path neuro formatted Flashcards

Question

26. 23.02.35 Schwannoma versus plexiform neurofibroma

Answer 1

Neurofibroma- schwann cell, fibroblast- NF1- uncommon - Involve cutaneous, spinal nn- 5-10% malignant degeneration- nerve fibre run through tumour- necrosis, cyst uncommon- histo: spindle cell, with intercellular collagen fibrils, myxomatous matrix- enhance- low T1, high t2 Schwannoma (5th -6th decade- schwan cell- NF2 (young patient)- common- involve CN8, spinal nn- no malignant degeneration- nerve eccentric from tumour- common to have cystic degeneration and haemorrhage- histo: spindle cell (Antoni A), looser mucoid stroma (Antoni B)- low 25% iso 75% T1, high T2

Answer 2

Answer : 1. Ganglioneuroma (Most well differentiated tumours comprised of ganglion cells and Schwann cells, without neuroblasts) 27. 23.03.12 Child with post paravertebral mass, biopsy shows acute neural elements and schwann cells not attached to nerve – DIAGNOSIS ? 1. Ganglioneuroma (Most well differentiated tumours comprised of ganglion cells and Schwann cells, without neuroblasts) 2. Ganglioglioma 3. Neurofibroma (Each fascicle is infiltrated by neoplasm – not possible to separate lesion from nerve) 4. Schwannoma (most common in 5th to 6th decade except in NF-2) 5. Neuroblastoma (appear as “small blue round cell tumour” - large nuclei, scant cytoplasm, solid sheets)

Answer 3

1. Lymphoma – 1° (Most common in immunosuppressed patients)

Answer 4

Answer:4. Meningioma (Cystic or necrotic change may be present - most often in parasagittal tumours (3 – 14%)) 29. 23.03.84 Cystic tumour in brain LEAST LIKELY is ? 1. Haemangioblastoma (60% are cystic masses with mural nodule that usually abuts pial surface) 2. JPA (Cerebeallar JPA 30% of total of JPA - Well-circumscribed mass with large cyst, and small reddish-tan mural nodule) 3. PNET (commonly cystic) 4. Meningioma (Cystic or necrotic change may be present - most often in parasagittal tumours (3 – 14%)) 5. Schwannoma (cystic change is common) 6. DNET (Well-defined “pseudocystic” lesion (high water content)) BR 1348 – cystic changes are a common finding

Answer 5

Probably 3?? • in some immunodeficient patients, reactivation results in disseminated infection and/or severe necrotizing meningoencephalitis and ependymitis • CMV may involve the CNS and/or peripheral nervous system • Neurologic manifestations of CMV thus include acute or chronic meningoencephalitis, cranial neuropathy, vasculitis, retinitis, myelitis, brachial plexus neuropathy, and peripheral neuropathy • The pathologic hallmark of CMV is the "owl's eye," an enlarged cell with a distended nucleus containing eosinophilic viral inclusions, surrounded by a halo, resulting in the characteristic appearance • The owl's eye appearance can be seen in ependymal cells, subependymal astrocytes, oligodendroglia, endothelial cells, and neurons. • Ependymal involvement is quite common. • Infrequently, CMV infection may result in extensive destruction of gray and white matter • Other typical histopathologic findings in the CNS include well-circumscribed microglial nodules, and CMV intranuclear inclusions may also be found in the spinal cord, spinal nerves, and retina • CT is frequently insensitive in the imaging of CMV encephalitis • The most common manifestation on CT is atrophy • Infrequently, white matter hypodensity may be apparent • Ring-enhancing lesions have also been described • CT grossly underestimates the degree of involvement by CMV o In addition to atrophy and white matter hypodensity, periventricular and subependymal enhancement may be seen and is best visualized with a double-dose delayed technique • MR has far greater sensitivity than CT in the detection of CNS CMV infection o In addition to atrophy, MR may demonstrate increased signal on T2-weighted images in the periventricular white matter, which may be patchy and is less often confluent o Infrequently, subependymal enhancement is evident and, if present, is a valuable diagnostic clue o Fat-suppressed MR with gadolinium may reveal a thickened enhancing choroid/retina in patients with CMV retinitis, a hemorrhagic retinitis affecting 20% to 40% of the AIDS population

Answer 6

2. CJD patients live for <12 months, vCJD live for a few years.

Answer 7

``` 4. Rosenthal fibres • Rosenthal fibres often present = eosinophilic bodies within astrocyte processes • up to 100% 5YS • Rosenthal fibers present in o Pilocytic astrocytoma o glioma o pineal tumor o Alexander’s disease o long-standing gliosis ```

Answer 8

1. Intracortical

Answer 9

4. adjacent to nose • Most common o Hemispheric convexity (20%) o Parasagittal (25%) → may occlude SSS • Very common o Sphenoid ridge, wing (15 – 20%) → may involve optic canal, wing meningiomas often en plaque Yock p26 Case 42 o Olfactory groove (5 – 10%) ``` • Common o Parasellar (5 – 10%) CR p79 Case 63 o Cavernous sinus CR p11 Case 7 • 66% partially or totally encase carotid artery • 33% narrow the artery ``` • Less common o CPA, along clivus (posterior fossa – 10%) Yock p38 Case 63 TA p3 Case 1 o Tentorium cerebelli Yock p36 Case 59 o Foramen magnum Yock p38 Case 64 • Rare o Optic nerve sheath (<2%) CR p155 Case 119 o Extracranial (nose, sinuses, skull (intraosseous)) o Intraventricular • usually trigone of (L) lateral ventricle Yock p40 Cases67-70 • most common trigonal mass in adults o Spinal canal (M : F = 1:10 ) • mostly thoracic region o Sylvian fissure Yock p31 Case 51 • Paediatric age group

Answer 10

1. majority occur at branch points • About 90% of berry aneurysms occur in the anterior circulation and are found near major arterial branch points. • Multiple aneurysms exist in 20-30% of autopsy series.

Answer 11

1. hippocampus

Answer 12

Answer: GBM. a. Pilocytic astrocytoma F - WHO grade I; bipolar cells with elongated hairlike processes; Rosenthal fibers; may have microscopically infiltrative margin; mural nodule may be highly vascular; often calcifications. Rarely malignant degeneration with hypercellularity, mitotic figures and necrosis. b. Glioblastoma multiforme T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation; with thickened vascular walls due to endothelial cell hyperplasia and hypertrophy; usually hypercellular with mitotic figures (some atypical), multinucleated tumor cells, bizarre nuclei, karyorrhectic cells; may have perinecrotic pseudopalisading of tumor cells around necrotic tumor. c. Acoustic schwannoma F - interlacing fascicles; biphasic with Antoni A (cellular) and B (myxoid) patterns and Verocay bodies (palisading nuclei); no/rare mitotic figures. Cystic change may be due to intratumoral hemorrhage. d. Craniopharyngioma F - Adamantinomatous (kids): relatively poorly circumscribed, nests and trabeculae of epithelium in fibrocollagenous stroma; nuclear palisading; often "wet" keratin, may undergo cystic degeneration, calcification, xanthogranulomatous reaction; cyst fluid contains cholesterol crystals, cholesterol clefts, reactive giant cells; variable necrosis, inflammation and Rosenthal fibers; no keratohyaline granules Papillary (adults): well-circumscribed, cores of fibrovascular stroma lined by well-diffd squamous epithelium that may form pseudopapillae. e. Ependymoma F - solid or papillary, small blue fibrillar to epithelioid cells with granular chromatin; form perivascular rosettes and less commonly ependymal rosettes. [Path outlines]

Answer 13

ANSWER: 1. DNET T - nodular intracortical lesion +/- cortical dysplasia, temporal lobe (62%). 38. Solid mass involving the cortex of a temporal lobe is demonstrated on MRI. The most likely diagnosis is: (GC) 1. DNET T - nodular intracortical lesion +/- cortical dysplasia, temporal lobe (62%). 2. Pilocytic astrocytoma F - usually cystic with mural nodule, may be solid or diffusely infiltrative (eg. optic n.). Usually midline - cerebellum, 3rd V, thalamus-hypothalumus. 3. Anaplastic astrocytoma F - found in hemispheres, usually frontal & temporal lobes. 4. Mesial temporal sclerosis F - 5. Pleomorphic xanthoastrocytoma F - most common in temporal lobe, superficial cortical location is typical, involves (attached to) leptomeninges. But is usually cystic (48%) with mural nodule; occasionally more diffuse with gyral infiltration. [Adelaide path notes, Dahnert]

Answer 14

ANSWER:1. Hippocampus 39. Least likely site for hypertensive bleed in the brain is: (GC) 1. Hippocampus 2. Cerebellum F - 10%; behave like SOL's - herniation & obstructive hydrocephalus. 3. Basal ganglia F - with thalamus account for 65% of hypertensive bleeds 4. Thalamus F - see above 5. Brainstem F - 10%

Answer 15

ANSWER: 2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. 1. H2O soluble medium cannot pass if normal BBB T - solutes with high affinity for plasma water, low affinity for plasma proteins, and high extremely low partition coefficients do not penetrate normal BBB (eg. contrast media). 2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. 3. Capillaries are continuous T - this is the basis of the BBB. Other types are fenestrated (circumventricular organs), and sinusoidal (liver, spleen, bone marrow). 4. Continuous capillaries have no fenestrations T - wall is composed of a single layer of endothelial cells connected by tight junctions, surrounded by a continuous basement membrane. It is the continuity of the interendothelial tight junctions, lack of pinocytosis and absence of fenestrations that contribute to the restricted permeability of the BBB. 5. Tight junctions are important T - see above.

Answer 16

ANSWER: a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. 41. Cortically based lesion, which is most likely: (GC) a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. b. Low grade glioma F c. Meningioma F - extra axial. Rarely atypical meningiomas may show sarcomatous transformation with spread over entire hemisphere and invasion of cerebral parenchyma (leptomeningeal supply). d. Ependymoma F - supratentorial tumours frequently grow into brain parenchyma extending to the cortical surface, esp in frontal and parietal lobes. May see scalloping of inner table or invasion of overlying meninges/bone. [Dahnert]

Answer 17

ANSWER: d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) 42. Which is least likely to involve the corpus callosum: (GC) a. GBM T - most commonly spread via direct extension along WM tracts, including the CC - classic butterfly pattern. b. Marchifava Bignami T - primarily affects the CC - acute form affects the genu & splenium, chronic form affects the body. c. DAI T - classic triad of GW junction, dorsolateral brainstem, and CC (most commonly eccentrically and in the splenium). d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) e. Lymphoma T - differ from GBM as usually less peritumoral oedema, less often necrotic, highly radiosensitive, frequently respond dramatically to steroids. [AJR 2002] Completed using stems from Aug 2006, previously only had DWS [Eric] ``` Associated anomalies include: o Chiari II malformation o Dandy-Walker complex o Neuronal migration disorders o Cephalocoeles o Schizencephaly o Interhemispheric lipoma – tubulonodular type o Azygous anterior cerebral arteries ```

Answer 18

ANSWER:1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 43. GBM what is the most important feature in Dx: (GC) 1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 2. Angiogenesis ? - microvascular proliferation is also a Dx feature 3. Cystic change F - non specific feature 4. Mitosis F - abnormal mitoses are also present in grade III (anaplastic) astrocytoma 5. Vasogenic oedema F - non specific feature WHO grading & Histological criteria: I Pilocytic astrocytoma - II Diffuse astrocytoma - 1 criterion, usually nuclear atypia III Anaplastic astrocytoma - 2 criteria, usually nuclear atypia and mitoses IV Glioblastoma - 3 criteria, usu nuclear atypia, mitoses, microvasc proliferation +/or necrosis

Answer 19

1. Detectable at angiography F - most are angiographically occult due to slow flow. 44. Cavernous Angioma – which is is not typical: (GC) 1. Detectable at angiography F - most are angiographically occult due to slow flow. 2. Bleeding tendency T - nearly all show evidence of recent and remote hemorrhage, as suggested by the presence of hemosiderin-laden macrophages, cholesterol crystals, and hemosiderin-stained parenchymal tissues. 3. No intervening normal brain - this is the only histopathologic characteristic that distinguishes these lesions from capillary telangiectasias. 4. Pseudocapsule + surrounding hemosiderin laden macrophages T - clots and blood products of various stages of evolution within the lesion, as well as calcification and gliosis surround the cavernoma, creating the appearance of a pseudocapsule. 5. Associated venous angioma T - persistent elevations in venous pressures, as may be seen locally within a venous malformation, may promote a pathologic reactive angiogenesis or angiogenic proliferation, resulting in abnormal blood vessel growth and coalescence. [eMedicine]

Answer 20

ANSWER:1. Chickenpox Dahnert includes it in "Other", p232. ? T - Congenital varicella syndrome occurs in 2% of children born to women who develop varicella during the 1st or 2nd trimester of pregnancy. Manifests as IUGR, cortical atrophy, microcephaly, microphthalmia, cataracts, limb hypoplasia, skin scarring. 45. Which of the following is not a congenital CNS infection: see Aug 2007 (GC) 1. Chickenpox Dahnert includes it in "Other", p232. ? T - Congenital varicella syndrome occurs in 2% of children born to women who develop varicella during the 1st or 2nd trimester of pregnancy. Manifests as IUGR, cortical atrophy, microcephaly, microphthalmia, cataracts, limb hypoplasia, skin scarring. 2. Rubella T 3. CMV T 4. Toxoplasmosis T 5. Herpes In utero infection is rare; 3% of these will have severe symptoms of skin vesicles/scarring, eye disease, microcephaphaly/hydranencephaly. HSV-2 is most commonly acquired during vaginal delivery (intrapartum), can also occur postnatally (horizontal transmission).

Answer 21

ANSWER:1. a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial cells with abundant eosinophilic, granular cytoplasm, termed Hurthle cells.1. 46. Hashimoto’s – FNA findings (TW) a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial cells with abundant eosinophilic, granular cytoplasm, termed Hurthle cells. b. Fibrosing nodules - F - Reidel's thyroiditis. c. Psammoma bodies - F - in papillary thyroid carcinoma. Concentrically calcified structures.= o ns = Hurthle cells seen in: o Hashimotos o Follicular adenoma

Answer 22

ANSWER:2. Lewy Bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease 47. Which is not a feature of Alzheimer’s: (GC). 1. Hirano bodies T - elongated glassy eosinophilic bodies of paracrystallline arrays of beaded filaments predominantly of actin, found mostly in hippocampal pyramidal cells in AD. 2. Lewy Bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease. 3. Senile Plaques T - aka neuritic plaques; focal spherical collections of dilated tortuous silver-staining neuritic processes (dystrophic neurites) surrounding a central amyloid core. 4. Neurofibrillary tangles T - bundles of filaments in cytoplasm of neurons that displace or encircle the nucleus, 'flame-shaped', seen well with silver staining (especially in cortical neurones). Characteristic but not specific to AD; also seen in PSNP, postencephalitic PD, ALS-parkinsonian-dementia complex of guam (!) 5. Granulovacuolar degeneration T - small clear intraneuronal cytoplasmic vacuoles, each containing a granule. 6. Amyloid T - almost an invariable accompaniment of AD. Beta-amyloid and its precursor protein (APP) are implicated in the aetiopathogenesis.

Answer 23

ANSWER:2. Angiogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 48. PNET, which is the most typical appearance: (GC) Eric had 'cystic' for this answer 1. Cortical F - deep cerebral white matter, most commonly frontal lobe. 2. Angiogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 3. Cystic F - large (hemispheric) heterogeneous mass with tendency for necrosis (65%), cyst formation, calcification (71%), haemorrhage (10%). 4. Vasogenic oedema F - thin rim of oedema 5. Astrocytoma [Dahnert] (--)Location - Supratentorial, most commonly located in frontal, parietal lobes next to lateral ventricle - Can be intraventricular - May include olfactory neuroblastoma (esthesioneuroblastoma) Morphology - Large bulky hemispheric mass with necrosis, cyst formation, haemorrhage & prominent vessels, densely cellular - Histol: small undifferentiated cells, Homer Wright pseudorosettes rarely Psammoma bodies: a form of dystrophic calcification. A necrotic cell forms a focus for crystal deposition and layers form around it. Associated with: Papillary carcinoma Renal cell carcinoma Meningioma Female genital tract tumours Breast cancer

Answer 24

ANSWER:2. Typically involves superior frontal lobes 1. In HSV I encephalitis, which is least correct 1. Age 50-70 years 2. Typically involves superior frontal lobes 3. Commonest presentation is headache 4. May present with seizures, ataxia and lethargy

Answer 25

Some people say 1, some 2 1. Central pontine myelinosis - F - central symptoms ALOC, pseudobulbar palsy, dysarthria, dysphagia. 2. Pontine myelinosis, midbrain and supratentorial changes - T - probably best answer :Extrapontine myelinolysis (now known as - along with CPM - osmotic demyelination syndrome). Movement problems, along with the CPM problems of pseudobulbar palsy, dysarthria, dysphagia, ALOC. 3. Pontine lesion secondary to Thiamine deficiency - F - wernickes encephalopathy tends to be symmetrical distribution in structure surrounding 3rd ventricle, aqueduct, and 4th ventricle. Typically mamillary bodies, periaqueductal gray matter, hypothalamus, and thalami adjacent to 3rd ventricle. 4. Subacute combined degeneration of cord secondary to thiamine deficiency - F - this would be best answer if was cobalamin (Vit B12) deficiency and not thiamin (B1) in regards to subacute combined degeneration. Cobalamin deficiency can cause paraesthesia of lower limbs, ataxia, to the extent of complete paraplegia. Realistically, the clinical presentation is probably related to the PFO + head trauma + coagulopathic + bleed. 5. Cord degeneration secondary to folate deficiency - F - deficiency of both cobalamin (B12) and folic acid produce megaloblastic anemia, but only B12 deficiency produces neurologic changes. 6. Hashimoto’s thyroiditis - F

Answer 26

ANSWER:1. Ganglioneuroma - T - The most well-differentiation lesions (in the neuroblastoma spectrum) - see ganglion cells and Schwann cells, and neuroblasts are no longer present. 3. Child with posterior paravertebral mass, biopsy shows mature neural elements and Schwann cells not attached to nerve – diagnosis is (TW) 1. Ganglioneuroma - T - The most well-differentiation lesions (in the neuroblastoma spectrum) - see ganglion cells and Schwann cells, and neuroblasts are no longer present. 2. Ganglioglioma - F - tumor of neoplastic astrocytes (rarely oligodendrocytes) and ganglion cells. 3. Neurofibroma - F - PNST arise from cells of the peripheral nerve (Schwann cells, perineural cells, fibroblasts) - attached to nerve, but can be separated from it 4. Schwannoma - F - PNST - see ans 3. 5. Neuroblastoma - F- small, primitive-appearing cells with dark nuclei, scant cytoplasm, and poorly defined cell borders growing in solid sheets. Certain NBs may have some degree of differentiation with clusters of larger cells resembling ganglion cells.

Answer 27

*LW: hopefully incomplete recall, as technically all of the 4 listed options can be classified as small round blue cells. Wilms tumour can be included within this category, with blastemal cells representing small round blue cells. ANSWER:4. Wilms tumour - F - classic Wilms tumor comprised of 3 cell types - Blastemal cells (undifferentiated cells), Stromal cells (immature spindle cells and heterologous skeletal, cartilage, osteoid, or fat), and epithelial cells (Glomeruli and tubules). 4. Child with mass FNA shows small round blue cells- least likely diagnosis is (TW) 1. Neuroblastoma - T - small, primitive-appearing cells with dark nuclei, scant cytoplasm, and poorly defined cell borders growing in solid sheets. 2. Ewing’s sarcoma - T - monotonous sheets of small round blue cells with hyperchromatic nuclei and scant cytoplasm. 3. Rhabdomyosarcoma - T - subtypes Botryoid and spindle cell (leiomyomatous / Embryonal / Alveolar / Undifferentiated. Histo of embryonal and alveolar types - cells have scant cytoplasm and a centrally placed round nucleus that occupies the majority of the cell. 4. Wilms tumour - F - classic Wilms tumor comprised of 3 cell types - Blastemal cells (undifferentiated cells), Stromal cells (immature spindle cells and heterologous skeletal, cartilage, osteoid, or fat), and epithelial cells (Glomeruli and tubules). 5. Retinoblastoma - T - sheets, trabeculae and nests of small blue cells with scant cytoplasm.Ewing's sarcoma family of tumors (EFT) includes Ewings sarcoma, extraosseous Ewing's sarcoma, more differentiated neuroectodermal tumors (PNET: previously AKA neuroepithelioma, adult neuroblastoms, Askin's tumor of chest wall).

Answer 28

ANSWER:3. Normal disorganised tissue in normal position - T - cellular elements are mature and identical to those found in remainder of organ, but do not reproduce the normal architecture of the surrounding tissue. Tumor-like malformation with tissues of particular part of body arranged haphazardly, usually with excess of one or more of its components. 5. Definition of Hamartoma is (TW) 1. Abnormal disorganised tissue in abnormal position 2. Abnormal disorganised tissue in normal position 3. Normal disorganised tissue in normal position - T - cellular elements are mature and identical to those found in remainder of organ, but do not reproduce the normal architecture of the surrounding tissue. Tumor-like malformation with tissues of particular part of body arranged haphazardly, usually with excess of one or more of its components. 4. Normal disorganised tissue in abnormal position Examples of hamartomas: hamartoma of lung, vascular hamartomas (hemangioma, lymphangiomas), melanotic hamartoma (melanocytic naevus, spitz naevus, halo naevus, dysplastic naevus, blue naevus), skeletal hamartoms (exostoses), generalised hamartomatous dysplasias (NF, TS).

Answer 29

ANSWER:4. Meningioma - F - extraaxial. Necrosis, cysts, haemorrhage may be seen in 8-23%. Can have assoc trapped CSF clefts 6. Cystic tumour in brain, least likely is (TW). 1. Hemangioblastoma - T - typically adult with intra-axial posteior fossa mass with cyst, enhancing mural nodule abutting pia. 2. JPA - T - common cystic lesion with mural nodule in children 3. PNET - T - PNET-MB - most common PF tumor in children (debatable vs JPA). Small intratumoral cysts / necrosis 40-50%. 4. Meningioma - F - extraaxial. Necrosis, cysts, haemorrhage may be seen in 8-23%. Can have assoc trapped CSF clefts. 5. Schwannoma - T - peripheral nerve sheath tumor which can be cystic and intraparenchymal. 1-2% intracerebral (superficial or periventricular location, cerebral hemisphere is most common site). Intracerebral schwannoma = cyst with nodule.Osborn.

Answer 30

ANSWER:2. Cerebellar vermis - F 7. Multiple sclerosis, least likely finding is (TW )1. Cerebellar white matter - T - cerebellar peduncles are classic. 2. Cerebellar vermis - F 3. Corpus callosum - T - typically mutliple perpendicular callososeptal T2 hyperintensities. 4. Peri venular - T - perpendicular lesions in perivenular distribution. >85% lesions periventricular / perivenous. 50-90% callososeptal interface. Perivenular extnsion "Dawson finger" along path of deep medullary veins.

Answer 31

2. Peripheral arterial - T - peripheral to first bifurcation of major vessel (45%); often located near surface of brain especially over convexities.

Answer 32

ANSWER:1. 1. Shy Drager - T - known as multiple system atrophy. Sky-Drager syndrome still used sometimes for MSA when primary symptoms are autonomic failure. MSA - striatonigral degeneration is clinically similar to idiopathic PD in presentation, but is relatively resistent to L-dopa treatment (due to pattern of neuronal degeneration - ie both dopaminergic projections and its target neurons are absent, therefore L-dopa cannot bulster neurotransmission as occurs in parkinsons disease). 9. Patient with drug resistant Parkinson’s and autonomic neuropathy, most correct option (TW)ANSWER:1. 1. Shy Drager - T - known as multiple system atrophy. Sky-Drager syndrome still used sometimes for MSA when primary symptoms are autonomic failure. MSA - striatonigral degeneration is clinically similar to idiopathic PD in presentation, but is relatively resistent to L-dopa treatment (due to pattern of neuronal degeneration - ie both dopaminergic projections and its target neurons are absent, therefore L-dopa cannot bulster neurotransmission as occurs in parkinsons disease). 2. Drug resistant Parkinson’s - F - autonomic neuropathy too. 3. Striatonigral degeneration - F - can see in PD and MSA 4. Olivopontocerebellar atrophy - F 5. Progressive supranuclear palsy - F

Answer 33

ANSWER:4. Involvement of post ⅔ superior temporal gyrus & parietal lobe - F - spared posterior aspect of superior temporal gyrus and pre- and postcentral gyri. Unremarkable parietal and occipital lobes. Picks disease / Frontotemporal dementia - nonspecific songioform degneration, with gliosis and neuronal loss, sometimes with Pick cells and bodies. 25-40% of FTD is familial. 10-30% of patients with positive family history have tau mutations (Tauopathy). 9. Pick’s disease, uncommon findings (TW) 1. Asymmetrical atrophy - T - worse atrophy of dominant hemisphere 2. Predominant frontal lobes - T - anterior frontotemporal atrophy. 3. Cortical atrophy - T - thin cortex. Gliosis of corticl gray matter. Soft, retracted subcortical white matter. Almost complete loss of large pyramidal neurons, diffuse spongiosis and gliosis. 4. Involvement of post ⅔ superior temporal gyrus & parietal lobe - F - spared posterior aspect of superior temporal gyrus and pre- and postcentral gyri. Unremarkable parietal and occipital lobes.Picks disease / Frontotemporal dementia - nonspecific songioform degneration, with gliosis and neuronal loss, sometimes with Pick cells and bodies. 25-40% of FTD is familial. 10-30% of patients with positive family history have tau mutations (Tauopathy).

Answer 34

1. Primary lymphoma - T - most notable risk factor for development of primary CNS lymphoma is immunodeficiency. Solid organ transplant patients have 30-50x higher incidence of lymphoproliferative disorder cf general population.

Answer 35

ANSWER:4. Giant cell arteritis - F - GCA is a chronic vasculitis of large and medium sized vessels. Mean age at Dx is approx 72yo, and the disease essentially never occurs in individuals younger than 50yo (UpToDate). 12. 40 year old female with stroke, underlying cause least likely is (TW) 1. Atherosclerosis - T 2. Dissection - T 3. Coarctation of aorta - T- congenital or acquired (eg inflammatory diseases of aort such as Takayasu). Previously undiagnosed adults - classic presenting sign is hypertension. 4. Giant cell arteritis - F - GCA is a chronic vasculitis of large and medium sized vessels. Mean age at Dx is approx 72yo, and the disease essentially never occurs in individuals younger than 50yo (UpToDate). 5. Mitral valve prolapse - T - most common congenital cause of MR in adults. Natural history of MVP is generall benign, but serious complications do occur; the most common are infective endocarditis, CVAs, need for MV surgery, death.

Answer 36

ANSWER:2. Anaplastic thyroid cancer in a 29 year old - F - older patients, mean age 65yo. 1. Sep03.26 Atypical Scenario (TW)1. Craniopharyngioma in a 42 year old - T - Bimodal age distribution (peak 5-15yo; papillary craniopharyngioma >50y). 2. Anaplastic thyroid cancer in a 29 year old - F - older patients, mean age 65yo. 3. Bowel cancer in a 32 year old - T - peak incidence for CRC is 60-70yo. CRC in a young person, preexisting UC or one of teh polyposis syndromes must be suspected. 4. Cholangiocarcinoma in a young adult with emphysema - T - a-1-antitrypsin deficency predisposes to cholangiocarcinoma.

Answer 37

ANSWER:4. Multipolar cells with microcysts, and bipolar cells with Rosenthal fibres - T - classic "biphasic" pattern of two astrocyte populations: compacted biplar cells with Rosenthal fibers (electron dense GFAP staining cytoplasmic inclusions); Loose-textured multipolar cells with microcysts, eosinophilic granular bodies.Expanded option 4. Previous said "...... fibers (this is correct ans)" 2. Sep03.28 Pilocytic Astrocytoma (TW) 1. Associated with NF2 - F - NF1. 15% of NF1 patients develop PAs (most commonly in optic pathway). Upt o 1/3 of patients with optic pathway PAs have NF1. 2. 50% are solid - F - 40% solid with necrotic center, heterogeneous enhancement. 10% solid, homogeneous. 50% non enhancing cyst with enhancing mural nodule. 3. Prognosis is less than 70% 5 year survival rate - F - median survival rates at 20y >70% 4. Multipolar cells with microcysts, and bipolar cells with Rosenthal fibres - T - classic "biphasic" pattern of two astrocyte populations: compacted biplar cells with Rosenthal fibers (electron dense GFAP staining cytoplasmic inclusions); Loose-textured multipolar cells with microcysts, eosinophilic granular bodies.Expanded option 4. Previous said "...... fibers (this is correct ans)"

Answer 38

ANSWER:1. Very radio sensitive. Excellent prognosis even if it extends retro-orbitally - F - enuleation usually is indicated for large tumors with not visual potential, blind, painful eyes, and/or tumors that extend into the optic nerve. External beam XRT was original globe-sparing treatment for Rb. Risk of tumor recurrence following ext XRT 7%, occurring within 40months. Also risk of secondary cancers with XRT. UpToDate 3. Sep03.41Retinoblastoma, which is the least likely ? (TW). 1. Very radio sensitive. Excellent prognosis even if it extends retro-orbitally - F - enuleation usually is indicated for large tumors with not visual potential, blind, painful eyes, and/or tumors that extend into the optic nerve. External beam XRT was original globe-sparing treatment for Rb. Risk of tumor recurrence following ext XRT 7%, occurring within 40months. Also risk of secondary cancers with XRT. UpToDate. 2. Carriers of RB gene have a 90% risk - T - If a mutant RB allele arises in the germ line, it can be transmitted as a dominant trait, and carriers are at high risk (>90% risk for most mutations) for retinoblastoma. Robbins. 3. Can get extraocular Retinoblastomas - T - trilateral RB = bilateral RB with neuroectodermal pineal tumor. Quadrilateral RB = trilateral RB with 4th focus in suprasellar cistern. Dahnert 6th.

Answer 39

ANSWER:1. Intracortical T - well-demarcated "bubbly" cortical mass 3. Sep03.64 DNET: (TW & GC) 1. Intracortical T - well-demarcated "bubbly" cortical mass 2. Cystic F - pseudocystic imaging appearance due to hypodensity. Histology may show "floating neurons" + mucinous degeneration. 3. Angiogenesis F - pathological hallmark is the "specific glioneuronal element": columns of heterogeneous cells oriented perpendicular to cortex. Also glial nodules and cortical dysplasia. 4. WHO grade II F - grade I 5. Frontal lobe F - temporal lobe 62%, frontal lobe 31%[Adelaide notes, Dahnert, RG 2001]

Answer 40

4. adjacent to nose - Atypical location. Ectopic = extradural meningioma: <1% cases, intradiploic space, outer table of skull, scalp, paranasal sinus, parotid gland, parapharyngeal space, mediastinum, lung, adrenal gland. Types of meningioma: - Globular meningioma (most common): compacted roundd mass with invagination of brain; flat at base; contact to falx / tentorium / basal dura / convexity dura. - Meningioma en plaque: pronounced hyperostosis of adjacent bone particularly along base of skull; difficult to distinguish hyperostosis from tumor cloaking the inner table - Multicentric meningioma (2-9%): tendency to localize to a single hemicranium; present clinically at earlier stage. CSF seeding is exceptional; in 50% assoc with NF2.

Answer 41

ANSWER: 1.1. paraganglioma, chemodectoma, and carotid body tumors can be used interchangeably - F - multiple names: glomus tumor, chemodectoma, endothelioma, perithelioma, sympathoblastoma, fibroangioma, sympathetic nevi. Paragangliomas are classified based on their location, innervation, and microscopic appearance. Would need to specify location for paraganglioma / chemodectoma to be able to use interchangeably with carotid body tumor. 6. Sep03.74 Paragangliomas (TW)ANSWER: 1. 1. paraganglioma, chemodectoma, and carotid body tumors can be used interchangeably - F - multiple names: glomus tumor, chemodectoma, endothelioma, perithelioma, sympathoblastoma, fibroangioma, sympathetic nevi. Paragangliomas are classified based on their location, innervation, and microscopic appearance. Would need to specify location for paraganglioma / chemodectoma to be able to use interchangeably with carotid body tumor. 2. carotid body tumors often adherent to vessels resulting in incomplete excision and recurrence of 10% - T - Shamblin classification - Type I are localized and easily removed; type II adherent and partially surround carotid vessels; type III adherent and completely surround carotid vesels and extremely difficult to resect often requiring resection of ICA and vein graft interposition. Prevalence of local recurrence and local invasion - 40-50% of glomus jugulare tumors, 17% for vagal paragangliomas, and about 10% for carotid body tumors. 3. glomus jugulare and carotid body paragangliomas are the most common head and neck paragangliomas - T - conflicting reports regarding the prevalence of these 2 subtypes some saying one is more prevalent, some saying the other is. 4. paragangliomas have biphasic or biphenotypic pattern and composed of chief cells and sustentacular cells - T

Answer 42

ANSWER:4. majority of newborns have systemic signs of disease, of which about half have CNS involvement - F - most infected newborns appear normal. 10% have systemic signs of disease (hepatosplenomegaly, petechiae, chorioretinitis, jaundice, and IUGR). 55% with systemic disease have CNS involvement (microcephaly, parenchymal Ca+, SNHL, seizures, hypotonia or hypertonia). 7. Sep03.17 CMV encephalitis: which is false? (TW) 1. characteristic inclusions - T - CMV inclusion-bearing cells. Prominent cytomegatic cells with intranuclear and intracytoplasmic inclusions can be readily identified. Hallmark is cytomegaly with viral nuclear and cytoplasmic inclusions. 2. ependymal & subependymal involvement - T - may affect any cell type by striking tendency for virus to localise in teh epehdymal and subependymal regions of brain. Replicates in ependyma, germinal matrix, and capillary endothelia. 3. may cause haemorrhage - T - results in severe necrotising ventriculo-encephalitis with massive necrosis, haemorrhage, ventriculitis and choroid plexusitis 4. majority of newborns have systemic signs of disease, of which about half have CNS involvement - F - most infected newborns appear normal. 10% have systemic signs of disease (hepatosplenomegaly, petechiae, chorioretinitis, jaundice, and IUGR). 55% with systemic disease have CNS involvement (microcephaly, parenchymal Ca+, SNHL, seizures, hypotonia or hypertonia).

Answer 43

CJD patients live for <12 months, vCJD live for a few years - T - mean duration illness for vCJD 14months, for CJD 4-5months. Both diseases are progressive and uniformly fatal 8. Sep03.18 CJD & variant CJD (TW) 1. caused by a slow virus - F - rapidly progressing, fatal, potentially transmissible dementing disorder caused by a prion (proteinaceous infectious particle devoid of DNA and RNA) 2. CJD patients live for <12 months, vCJD live for a few years - T - mean duration illness for vCJD 14months, for CJD 4-5months. Both diseases are progressive and uniformly fatal 3. Associated with marked frontal atrophy - F - get abnormal signal in predominantly gray matter - Basal ganglia (caudate nuclei, putamina, and to lesser extend globi pallidi) thalami. Cerebral cortex (most commonly frontal and temporal lobes). Mild cortical atropy - diffuse or confined to affected structures. Ventricular enlargement.

Answer 44

ANSWER: 3. Type 3 antigen antibody complex 13. Sep03.63 IV contrast, 4 -12 hrs afterwards, it results in skin necrosis. It’s a repeatable response. What type of reaction is it? (TW) 1. Type 1 hypersensitivity - F- Anaphylactic type. Rapidly developing immunologic reaction developing within minutes after combination of antigen with antibody bound to mast cells or basophils in individuals previously sensitized to antigen 2. Type 2 - F - Cytotoxic type. Mediated by antibodies directed toward antigens present on surface of cells or other tissue component (subtypes: complement-dependent reactions; antibody-dependent cell mediated cytotoxicity; antibody mediated cellular dysfunction) 3. Type 3 - T - Immunocomplex disease. Induced by antigen-antibody complexes that produce tissue damage as a result of their capacity to active the complement system. Can be generalized (immune complexes formed in circulation adn deposited in many organs etc), or localized to particular organs such as kidney (GN), joints (arthritis) or the small blood vessels of the skin if the complexes are formed an deposited locally (the local Arthus reaction). See below. 4. Type 4 - F - Cell mediated (delayed). Initiated by specifically sensitized T lymphocytes. 5. Non-immune reaction - F - unless someone is repeatedly extravasating a lot of contrast! Maybe fun, but not ethical.Local immune complex disease (Arthus reaction) - type III hypersensitivity reaction. Localized area of tissue necrosis resulting from acute immune complex vasculitis, usually elicited in the skin. Reaction can be produced by intracutaneous injection of antigen in an immune patient having circulating antibodies against the antigen. Unlike IgE mediated type I reactions, which appear immediately, the Arthus lesion develops over a few hours and reaches a peak 4-10hrs after injection, when it can be seen as an area of visible oedema with severe hemorrhage followed occasionally by ulceration.

Answer 45

ANSWER:3. Meningioma - F - Cystic or necrotic change may be present - most often in parasagittal tumours (3 – 14%) 14. Patient with brain tumor that appears cystic with a solid component--- least likely (TW) 1. Haemangioblastoma - T - 60% are cystic masses with mural nodule that usually abuts pial surface 2. JPA - T - Cerebeallar JPA 30% of total of JPA - Well-circumscribed mass with large cyst, and small reddish-tan mural nodule 3. Meningioma - F - Cystic or necrotic change may be present - most often in parasagittal tumours (3 – 14%) 4. Schwannoma - T - cystic change is common especially in intraparenchymal schwannomas. 5. DNET - T - Well-defined “pseudocystic” lesion (high water content)

Answer 46

ANSWER: 4. carcinoma in situ occurring within follicle-bearing epithelium – T - Usually appears as a solitary, dull-red plaque with areas of crusting and oozing. 15. Bowen Disease (TW) 1. associated with BCC in 5% of cases if left untreated - F - Bowen's disease - if left untreated - SCC develops in approx 5% of cases. 2. may have a penile cutaneous horn - F - penile cutaneous horn is an exophytic keratotic lesion fromed by overgrowth and cornification of the epithelium. CHs typically form on the surface of preexisting lesions such as nevi, warts, or traumatic abrasions. 3. results from chronic irritation and/or inflammation with development of scaly plaques often involving the meatus - F - this is leukoplakia. 4. carcinoma in situ occurring within follicle-bearing epithelium – T - Usually appears as a solitary, dull-red plaque with areas of crusting and oozing.

Answer 47

NSWER: 2. Cerebellar vermis - F 16. Multiple sclerosis, least common site (TW)A 1. Cerebellar white matter - T - cerebellar peduncles are classic. 2. Cerebellar vermis - F 3. Corpus callosum - T - typically mutliple perpendicular callososeptal T2 hyperintensities. 4. Perivenular - T - perpendicular lesions in perivenular distribution. >85% lesions periventricular / perivenous. 50-90% callososeptal interface. Perivenular extnsion "Dawson finger" along path of deep medullary veins.

Answer 48

* AJL - Agree with below. This is now called MSA-P (MSA with parkinsonian features). The other type of MSA is MSA-C (MSA with cerebellar symptoms/changes). 2. Shy Drager - T - known as multiple system atrophy. Sky-Drager syndrome still used sometimes for MSA when primary symptoms are autonomic failure. MSA - striatonigral degeneration is clinically similar to idiopathic PD in presentation, but is relatively resistent to L-dopa treatment (due to pattern of neuronal degeneration - ie both dopaminergic projections and its target neurons are absent, therefore L-dopa cannot bulster neurotransmission as occurs in parkinsons disease).

Answer 49

ANSWER:b. Toxoplasmosis - T- most common cause of focal lesion in HIV+. 18. HIV positive patient with CD4 count less than 100 has a mass on CT brain. What is the likely diagnosis? (TW) a. Lymphoma - F - less likely, although increased risk with immunosuppression. b. Toxoplasmosis - T- most common cause of focal lesion in HIV+. c. Cryptosporidium - F - less likely cf toxoplasmosis d. TB - F - less likely e. PML - F - diffuse/patchy WM abnormalities.

Answer 50

ANSWER: d. Decreased N-myc amplification T - less copies of gene is better 34. Neuroblastoma, which is not associated with a worse prognosis: (GC) a. Age > 1 year F - age < 1yr has a better prognosis b. Stage 4B F - stage 4S has a near 100% survival c. Abdominal primary F - thoracic primary has a better prognosis d. Decreased N-myc amplification T - less copies of gene is better e. Metastases to bone only F - mets to liver and skin is associated with better prognosis

Answer 51

2. Glioblastoma multiforme T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation; with thickened vascular walls due to endothelial cell hyperplasia and hypertrophy; usually hypercellular with mitotic figures (some atypical), multinucleated tumor cells, bizarre nuclei, karyorrhectic cells; may have perinecrotic pseudopalisading of tumor cells around necrotic tumor. 35. Necrosis is a characteristic feature of: (GC) 1. Pilocytic astrocytoma F - WHO grade I; bipolar cells with elongated hairlike processes; Rosenthal fibers; may have microscopically infiltrative margin; mural nodule may be highly vascular; often calcifications. Rarely malignant degeneration with hypercellularity, mitotic figures and necrosis. 2. Glioblastoma multiforme T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation; with thickened vascular walls due to endothelial cell hyperplasia and hypertrophy; usually hypercellular with mitotic figures (some atypical), multinucleated tumor cells, bizarre nuclei, karyorrhectic cells; may have perinecrotic pseudopalisading of tumor cells around necrotic tumor. 3. Acoustic schwannoma F - interlacing fascicles; biphasic with Antoni A (cellular) and B (myxoid) patterns and Verocay bodies (palisading nuclei); no/rare mitotic figures. Cystic change may be due to intratumoral hemorrhage. 4. Craniopharyngioma F - Adamantinomatous (kids): relatively poorly circumscribed, nests and trabeculae of epithelium in fibrocollagenous stroma; nuclear palisading; often "wet" keratin, may undergo cystic degeneration, calcification, xanthogranulomatous reaction; cyst fluid contains cholesterol crystals, cholesterol clefts, reactive giant cells; variable necrosis, inflammation and Rosenthal fibers; no keratohyaline granules Papillary (adults): well-circumscribed, cores of fibrovascular stroma lined by well-diffd squamous epithelium that may form pseudopapillae. 5. Ependymoma F - solid or papillary, small blue fibrillar to epithelioid cells with granular chromatin; form perivascular rosettes and less commonly ependymal rosettes. [Path outlines]

Answer 52

ASNWER: 1 .1. DNET T - nodular intracortical lesion +/- cortical dysplasia, temporal lobe (62%). 35. Solid mass involving the cortex of a temporal lobe is demonstrated on MRI. Most likely diagnosis is: (GC) ASNWER: 1 .1. DNET T - nodular intracortical lesion +/- cortical dysplasia, temporal lobe (62%). 2. Pilocytic astrocytoma F - usually cystic with mural nodule, may be solid or diffusely infiltrative (eg. optic n.). Usually midline - cerebellum, 3rd V, thalamus-hypothalumus. 3. Anaplastic astrocytoma F - found in hemispheres, usually frontal & temporal lobes. 4. Mesial temporal sclerosis F - 5. Pleomorphic xanthoastrocytoma F - most common in temporal lobe, superficial cortical location is typical, involves (attached to) leptomeninges. But is usually cystic (48%) with mural nodule; occasionally more diffuse with gyral infiltration. [Adelaide path notes, Dahnert]

Answer 53

ANSWER: 1.1. Hippocampus 35. Least likely site for hypertensive bleed in the brain is: (GC) ANSWER: 1.1. Hippocampus 2. Cerebellum F - 10%; behave like SOL's - herniation & obstructive hydrocephalus. 3. Basal ganglia F - with thalamus account for 65% of hypertensive bleeds 4. Thalamus F - see above 5. Brainstem F - 10% [Adelaide path notes]

Answer 54

*AJL 2. Fat soluble medium cannot pass if normal BBB - false. (just remember that contrast cannot pass the BBB and it is water soluble therefore water soluble medium cannot pass. The other one (fat) can pass) 35. BBB, which is incorrect: (GC) ANSWER: 2 1. H2O soluble medium cannot pass if normal BBB T - solutes with high affinity for plasma water, low affinity for plasma proteins, and high extremely low partition coefficients do not penetrate normal BBB (eg. contrast media). 2. Fat soluble medium cannot pass if normal BBB 3. Capillaries are continuous 4. Continuous capillaries have no fenestrations 5. Tight junctions are important

Answer 55

ANSWER:a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. 35. Which is most likely to involve cortex: (GC) a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. b. Low grade glioma F c. Meningioma F - extra axial. Rarely atypical meningiomas may show sarcomatous transformation with spread over entire hemisphere and invasion of cerebral parenchyma (leptomeningeal supply). d. Ependymoma F - supratentorial tumours frequently grow into brain parenchyma extending to the cortical surface, esp in frontal and parietal lobes. May see scalloping of inner table or invasion of overlying meninges/bone. [Dahnert] Changed 2. from low grade anaplastic astrocytoma

Answer 56

ANSWER:d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) 40. Which is least likely to involve the corpus callosum: (GC) a. GBM T - most commonly spread via direct extension along WM tracts, including the CC - classic butterfly pattern. b. Marchifava Bignami T - primarily affects the CC - acute form affects the genu & splenium, chronic form affects the body. c. DAI T - classic triad of GW junction, dorsolateral brainstem, and CC (most commonly eccentrically and in the splenium). d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) e. Lymphoma T - differ from GBM as usually less peritumoral oedema, less often necrotic, highly radiosensitive, frequently respond dramatically to steroids. [AJR 2002]

Answer 57

1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation

Answer 58

1. Detectable at angiography F - most are angiographically occult due to slow flow **LJS - also no intervening normal brain (stat dx)

Answer 59

2. Lewy bodies F - Parkinson's disease

Answer 60

*AJL - (from radiopaedia) The tumour appears as a large, demarcated, solid mass featuring patchy or no contrast enhancement, with surrounding oedema, often with significant mass effect. A minority of the reported cases have shown cystic components and microcalcifications. Therefore I think the answer is actually 4 - vasogenic oedema, based on current classification **LJS - not sure. ETMR replaces several tumours in new WHO classification, not just PNET. Let's hope the question is gone. But if not I would probably answer as per the old PNET classification and say angiogenesis. Previuos ANSWER:2. Angiogenesis T - 35. PNET, which is the most typical appearance: (GC) 1. Cortical F - deep cerebral white matter, most commonly frontal lobe. 2. Angiogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 3. Cystic F - large (hemispheric) heterogeneous mass with tendency for necrosis (65%), cyst formation, calcification (71%), haemorrhage (10%). 4. Vasogenic oedema F - thin rim of oedema 5. Astrocytoma F

Answer 61

ANSWER:2. Lateral and third ventricle in infants - anaplastic ependymoma (rare), usually in infants and children. See below 1. Commonest sites for ependymoma, which is least likely: (GC) .1. Periventricular areas T - supratentorial ependymoma is more commonly seated in the brain parenchyma, typically arising near the trigone of the lateral ventricle. Thought to arise from embryonic rests of ependymal tissue trapped in the developing cerebral hemispheres. Tend to be larger in size, more often cystic components cf. infratentorial. [RG 2005, eMedicine] 2. Lateral and third ventricle in infants - anaplastic ependymoma (rare), usually in infants and children. See below. 3. Fourth ventricle in children T - most commonly arises from floor of 4th ventricle. 4. Spine in adults T - common site, better able to excise completely and generally better prognosis. Most common intramedullary spinal neoplasm in adults.

Answer 62

ANSWER:2. Affects the putamen and caudate T - degeneration of the striatum (C&P). 2. Huntington's disease, which is true: (GC) 1. Autosomal recessive F - autosomal dominant disorder 2. Affects the putamen and caudate T - degeneration of the striatum (C&P). 3. Presents in the second decade F - age of onset most commonly in 4th and 5th decades, related to the length of the CAG repeat. 4. Chorea due to striatal excitation F - loss of striatal inhibitory output, from the degeneration of GABA-containing neurons. This leads to disregulation of the basal ganglia that normally modulate motor output.

Answer 63

Streptococci and staphylococci Nearly always caused by bacterial infections; direct implantation / local extension / haematogenous spread. 25% are cryptogenic. Predisposition: - diabetes - immunosuppressed - acute bacterial endocarditis (usu multiple), - cyanotic CHD (R-L shunt), chronic pulm sepsis. CSF: elevated white cell count and protein, normal glucose. Complications: - rupture with ventriculitis/meningitis - daughter abscesses - venous sinus thrombosis & infarction, - mass effect. [Robbins]

Answer 64

ANSWER:c. Wernicke's encephalopathy T - usually abrupt onset of nystagmus, gaze palsies, ataxia and mental confusion. Due to thamine (vit B1) deficiency. Korsakoff's syndrome is closely linked to Wernicke's and my be viewed as different stages of the same process - symptoms are of retentive memory impairment and confabulation 4. Chronic alcoholic; speech preserved, no facial droop, ataxia. Most likely diagnosis: (GC) A . a. Alcoholic cerebellar degeneration F - staccato speech, wide-based gait and truncal ataxia b. Marchiafava Bignami F - variable presentation, some with sudden onset stupor/coma or seizures, some with dementia and/or gait problems. Psychiatric disturbances, incontinence, hemiparesis, aphasia, and apraxia have been described. [eMedicine] c. Wernicke's encephalopathy T - usually abrupt onset of nystagmus, gaze palsies, ataxia and mental confusion. Due to thamine (vit B1) deficiency. Korsakoff's syndrome is closely linked to Wernicke's and my be viewed as different stages of the same process - symptoms are of retentive memory impairment and confabulation. d. Superior cerebellar artery infarct F - usually dysarthric as well as ataxic, +/- vestibular signs (N&V, dizziness). [Stroke 1996] e. Central pontine myelinolysis F - pseudobulbar palsy (head & neck weakness, dysphagia, and dysarthria), spastic quadriplegia, delirium is extremely common. May have horizontal gaze paralysis, or "locked-in syndrome" (paralysis of lower cranial nerves and limb musculature. Vertical eye movements, blinking, breathing, and alertness may remain intact in these patients). [eMedicine] Added options a, b, d, e.

Answer 65

4. Depletion of oligodendrocytes is a feature of MS lesions

Answer 66

ANSWER:d. Decreased N-myc amplification T - less copies of gene is better 7. Neuroblastoma, which is not associated with a worse prognosis: (GC) a. Age > 1 year F - age < 1yr has a better prognosis b. Stage 4B F - stage 4S has a near 100% survival c. Abdominal primary F - thoracic primary has a better prognosis d. Decreased N-myc amplification T - less copies of gene is better e. Metastases to bone only F - mets to liver and skin is associated with better prognosis [Paeds pocket rad]Added options a-c and e.

Answer 67

ANSWER:b. See INCREASED ADC value 33. In drug resistant Parkinsons and autonomic neuropathy an MRI would look for all the following except? (TW) - Multiple system atropy a. Striatonigral degeneration - T - predominant degeneration of substantia nigra and striatum, with putamen > caudate nucleus b. Decreased putaminal ADC values - F - DWI appears to differentiate Parkinsons Disease from progressive supranuclear palsy and the Parkinsons variant of multiple system atropy. c. Cerebellar atrophy - T - hemispheres > vermis d. Cruciform pontine hyperintensity - T - hot cross bun sign (but not pathognomonic of MSA) MSA - striatonigral degeneration: clinically similar to idiopathic PD in presentation but is relatively resistant to L-dopa treatment (due to pattern of neuronal degeneration - ie both dopaminergic projections and its target neurons are absent, therefore L-dopa cannot bulster neurotransmission as occurs in parkinsons disease). Also have gross atrophy of caudat nucleus and putamen. Some patients also show evidence of pontocerebellar degeneration.DWI - appears to differentiate PD from progressive supranuclear palsy and Parkinson variant of MSA. in MSA-Pv get increased putaminal ADC values. In PSP have increased ADC in putamen, GP, and caudate nucleus. Path notes. Osborn. Brain 2006 129(10).

Answer 68

2. periventricular veins - T - early lesion often centered on small veins, esp near ventricles and expansion often tracks along such vessels.

Answer 69

ANSWER:4. HIV positive - F - this is probably rare, however ADEM has been assoc with HIV-seroconversion illness. Probably getting you to Dx from PML. 9. Patient with possible ADEM. Which clinical setting least likely? (TW) 1. 2 week history of viral illness - T - monophasic (usually) demyelinating disease following either a viral infection, or, rarely, a viral immunisation. Typically develops a week or two after anticedent infection. 2. female - T - common finding. Male predominance reported in some series 1.3 : 1 3. headache and confusion progressing to coma in 48 hrs - T - usually fever, malasie, myalgia as prodromal phase. Then headache, fever, drowsiness. Can have cranial nerve palsies, seizures, hemiparesis, decreased consciousness (from lethargy to coma). 4. HIV positive - F - this is probably rare, however ADEM has been assoc with HIV-seroconversion illness. Probably getting you to Dx from PML. 5. Age less than 40 - T - peak age 3-5yo, but can occur at anytime

Answer 70

ANSWER:3. Alzheimers patients should have greater uptake in the medial temporal lobe than age matched control patients - T - degenerative process starts in medial temporal lobe, spreads to parahippocampal gyrus, temporal and frontal lobes, and finally involves motor and visual cortex. Get parietal and temporal cortical atrophy with disproportionate hippocampal volume loss. Predominates ijn medial temporal and pareital lobes. 10. A new Nuc Med agent can attach to the amyloid in neuritic plaques. Which is most correct? (TW) 1. Should help exclude congophilic angiopathy in the elderly - F - amyloid deposition not specific from amyloid angiopathy 2. Uptake would allow distinction between Alzheimers and age matched Parkinsons disease - Alzheimers neuritic plaques have amyloid core. Plaques can be found in non-demented patients but in lower numbers. 3. Alzheimers patients should have greater uptake in the medial temporal lobe than age matched control patients - T - degenerative process starts in medial temporal lobe, spreads to parahippocampal gyrus, temporal and frontal lobes, and finally involves motor and visual cortex. Get parietal and temporal cortical atrophy with disproportionate hippocampal volume loss. Predominates ijn medial temporal and pareital lobes. 4. Cerebellar uptake would suggest ataxic telangiectasia - F - pathology is neuronal degredation + atrophy of cerebellar cortex (? from vascular anomalies). 5. Deep cerebral uptake would suggest multi-infarct dementia or MS - F - infarcts, demyelination.

Answer 71

ANSWER: 11. Central pontine myelinolysis - T - Now referred to as Osmotic demyelination syndrome (previously CPM, or extrapontine myelinolysis). Demyelination due to (usually) osmotic stress related problems - but exact mechanism is not known. Isolated pons lesion is most common. Combined type: central and extrapontine areas (basal ganglia, cerebellar white matter, thalamus, caudate nucleus, subcortical cerebral white matter, corona radiata, lateral geniculate body). 11. An unconscious alcoholic with multiple medical problems is resuscitated with IV fluids and thiamine. MRI shows white matter lesions in pons, tegmentum and deep cerebral white matter. Which is most likely? (TW) ANSWER: 11. Central pontine myelinolysis - T - Now referred to as Osmotic demyelination syndrome (previously CPM, or extrapontine myelinolysis). Demyelination due to (usually) osmotic stress related problems - but exact mechanism is not known. Isolated pons lesion is most common. Combined type: central and extrapontine areas (basal ganglia, cerebellar white matter, thalamus, caudate nucleus, subcortical cerebral white matter, corona radiata, lateral geniculate body). 2. Beri-beri - F - thiamine deficiency (B1), and often manifests in cardiovascular collapse (wet beriberi). Nervous involvement - symmetric impairment of sensory, motor, and reflex functions (dry beriberi). 3. Wernicke – korsakoffs - F - Wernicke encephalopathy - mamillary body, medial thalamus, hypothalamus, PAG abnormal signal. Alcoholic encephalopathy - disproportionate superior vermain atrophy. 4. ETOH encephalomyelitis - F

Answer 72

ANSWER: 1 1. Benign sacrococcygeal teratoma - T - sacrococcygeal region is the most frequent tumor site of teratomas. SCTs occur most commonly in infants and may be Dx in utero, or at birth with the majority in females. Frequence of malignancy in this location varies from less than 10% when younger than 2mo, to more than 50% when older than 4mo (Nelson's pediatrics). Prevalence 1 in 35000 to 40000 births (Donnelly). 12. 34/40 fetus with large mass protruding posteriorly from sacrum. No evidence of Chiari malformation. Most likely is (TW) ANSWER: 1 1. Benign sacrococcygeal teratoma - T - sacrococcygeal region is the most frequent tumor site of teratomas. SCTs occur most commonly in infants and may be Dx in utero, or at birth with the majority in females. Frequence of malignancy in this location varies from less than 10% when younger than 2mo, to more than 50% when older than 4mo (Nelson's pediatrics). Prevalence 1 in 35000 to 40000 births (Donnelly). 2. Malignant sacrococcygeal teratoma - F - see ans 1. Only 17% of SCTs have malignant features (Donnelly paeds). 3. Congenital neuroblastoma - F - NB is most common extracranial solid malignancy in children. Most commonly arises from adrenal gland but can arise anywhere along sympatheti chain - so would be anterior and typically fills the pelvis. 4. Imperforate cloacal membrane - F5. Mature ganglioneuroma - F - like neuroblastoma, arise from primitive sympathetic ganglion cells, so symp chain - and anterior mass in pelvis.

Answer 73

3. Orthopnoea Friedrich ataxia - AR degenerative disorder. Most common hereditary ataxia. Most cases caused by loss of function in frataxin gene (frataxin is a mitochondrial protein whose prescise function is unknown).Neuropathology - degeneration of posterior columns and the spinocerebellar tracts of the spinal cord and loss of the larger sensory cells of the dorsal root ganglia.Major clinical manifestations of FQ - neurologic dysfunction, cardiomyopathy, and diabetes mellitus. Neuro - ataxia of limbs, absence of lower limb reflexes, and presence of pyramidial signs. Early loss of position and vibration sense. Cardiomyopathy - concentric LVH, asymmetric septal hypertrophy, and globally decreased LVF patterns of disease.Major causes of death are complications related to the cardiomyopathy or bulbar dysfunction, leading to an inability to protect the airway.

Answer 74

ANSWER:4. Recent neck manipulation - F - vert dissection, but probably least likely option. Population-based, case-control study found pts under 45yo, those with bertebrobasilar dissection or occlusion were 5x more likley than controls to have visited a chripractor in the previous week. Actual incidence reports vary (1 per 400 000 manipulations, to 2 per million). ***LJS - agree. Although at first glance all correct, neck manipulation would cause vertebral dissection, which is more likely to cause posterior fossa haemorrhage (cerebellar vs cerebral) 14. Hemorrhagic areas in cerebrum on CT. Least likely (TW & GC) 1. Recent pelvic fracture - T - fat emboli syndrome most commonly associated with long bone and pelvic fractures. Need pulmonary-precapillary shunt or shunt across pulmonary capillary bed, OR via PFO (ie absence of PFO doesn't exclude it). Fat globules < um can traverse the pulmonary microvasculature (in dogs). 2. Past rheumatic fever - T - risk for valvular disease / IE - emboli (could also be anticoagulated). Mitral stenosis - thromboembolic events of which 40% involve the brain or a large pulmonary embolism. 3. Active mastoiditis - T - direct extension / infection, localised abscess / encephalitis, venous sinus thrombosis + infarctions, typically haemorrhagic. 4. Recent neck manipulation - F - vert dissection, but probably least likely option. Population-based, case-control study found pts under 45yo, those with bertebrobasilar dissection or occlusion were 5x more likley than controls to have visited a chripractor in the previous week. Actual incidence reports vary (1 per 400 000 manipulations, to 2 per million). 5. Recent placental abruption - T - presuming this refers to the mother ('recent placental abruption') and not the fetus. There is a risk of abuption with eclampsia / HTN. Abruption can result in severe hypovoluemia, and coagulopathy. Severe abruption 1 in 830 deliveries - of which DIC is a common manifestation with CNS involvement in 2% (coma, delirium, mocrothrombi, haemorrhage, hypoperfusion). UpToDate.

Answer 75

ANSWER:2. Incorrect diagnosis - T 15. 65 year old, 3rd yearly follow up scan for CJD. Which is most correct? (TW) 1. This is expected as CJD is slowly progressive - F - rapidly progressive mental deterioration and myoclonus (sCJD). Mean duration of illness for sCJD 4-5months (howevers urvival range varies depending on subtype of sCJD). 2. Incorrect diagnosis - T 3. Patient most likely has variant CJD - F - mean duration of illness 14months. 4. CJD has variable progression with 10-15% having a long term survival of > 10 years - F - both vCJD and sCJD are progressive and uniformly fatal. Occasional case reports of survival to 40-50months, but rare. 5. Patient more likely to have the more indolent familial form - F - fCJD accounts for 10-15% cases. Longer survival - mean duration 26 months. Age little younger than sCJD (~60yo). So could be this then - SG

Answer 76

Answer: 4. Spinal cord - F - toxoplasmosis of the spinal cord is less frequent than in the brain (in HIV), and has become even less common cause of myelopathy after the introduction of HAART ). [The neurology of AIDS, H Gendelman] 5. Putamen - T - basal ganglia in up to 75%

Answer 77

2. post obstetric patient - T - think this is most correct. * *LJS - 30-40% SLE pt have antiphospholipid Ab = recurrent arterial and venous thrombosis. ?higher risk than post-partum * **LW: 2019 consensus statement states 5-17% of cerebral venous infarction / thrombosis have SLE related conditions, while 1% to 59% are peri partum and 54% to 71% of cases are on OCP. So i still favour post obstetric patient as most correct option. (https: //www.ahajournals.org/doi/10.1161/STROKEAHA.119.025334) 17. Most at risk for cerebral venous infarction (TW) ANSWER: 2 1. diabetic in renal failure 2. post obstetric patient - T - think this is most correct. 3. young girl on progesterone only pill - F - oestrogen is major prothrombotic component. Progesterone much lower risk. Most frequent risk factor for cerebral venous sinus thrombosis is the OCP (but this is presumably the oestrogen containing one). 4. young girl with SLE

Answer 78

ANSWER: 11. Hydatid / echinococcus - T - large uni- or multilocular cyst +/- detached germinal membraine. Cyst fluid is opalescent. 18. Solitary 3cm cystic lesion in the brain containing an opaque gel-like substance (TW) ANSWER: 1. Hydatid / echinococcus - T - large uni- or multilocular cyst +/- detached germinal membraine. Cyst fluid is opalescent. 2. Cysticercosis - F - although most common parasitic infection world wide, cyst size is variable and typically 1cm, with range of 4-20mm. Parenchymal cysts 1cm or less, however subarachnoid systs may be larger, up to 9cm reported (and recemose). Cysts are ovoid and white-to-opalescnet, rarely exceeding 1.5cm. Contain an invaginated scolex with hooklets that are bathed in clear cyst fluid. 3. Amoebiasis - F - cerebral amebiasis is a rare cause of brain abscess. Amebic encephalitits - hyperintense lesions +/- haemorrhage. 4. Strongyloides - F 5. Ascaris - F

Answer 79

ANSWER: 5. osteosarcoma - F - couple of case reports of NF1 and osteosarc, but not indicated that is associated. Note however that NF1 is assoc with sarcomas. Malignancy in Neurofibromatosis Type 1. The Oncologist Vol 4, No 5, 477-485. Dec 2000. 19. NF1 – which is not/least associated (TW) 1. Wilms - T - mixed data. Seems to have assoc (NF1 has been assoc with tumors of embryonic origin, such as Wilms tumor, rhabdomyosar, leukemia [Med and Ped Onc 2002]). 2. Rhabdomyosarcoma - T - increased rate 3. CML - T - NF1 have increased risk of CML, ALL, NHL. 4. phaeochromocytoma - T - higher frequency 5. osteosarcoma - F - couple of case reports of NF1 and osteosarc, but not indicated that is associated. Note however that NF1 is assoc with sarcomas. Malignancy in Neurofibromatosis Type 1. The Oncologist Vol 4, No 5, 477-485. Dec 2000.

Answer 80

ANSWER: 11. Pick's disease - focal cortical atrophy of anterior frontal and anterior temporal lobes 20. White matter disease, least likely: (GC) ANSWER: 11. Pick's disease - focal cortical atrophy of anterior frontal and anterior temporal lobes. 2. ADEM 3. DAI

Answer 81

. Cord involvement F - can't find any literature on this. 1. Central pontine myelinolysis, which is least correct: (GC) a. Oesophageal varices T - 60-70% of CPM occurs in chronic alcoholics, who are more likely to have chronic liver disease and varices. b. Cord involvement F - can't find any literature on this. c. Resuscitation with IV fluids if hypotensive T - aggressive IVH with hypertonic saline solutions may precipitate CPM. However, many patients with hypoNa+ that is corrected rapidly do not develop CPM. d. Supratentorial involvement T - extrapontine myelinolysis: BG, thalamus, caudate nucleus, subcortical cerebral WM, corona radiata, lateral geniculate body. Also may occur in cerebellar WM. e. Recent quadriparesis T - spastic quadriplegia, pseudobulbar palsy & "locked-in" state. [eMedicine, Dahnert 6th p273] Changed Qu from "least likely", changed option d. from "supracortical"

Answer 82

5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children. 21. Children with Ependymoma, which is false: (GC) 1. Prognosis poor – cannot remove completely T - Despite the survival advantage of gross total resection, lesions of the posterior fossa are in close proximity to cranial nerves with a significant risk of long-term neurologic dysfunction and disability. Hence, most tumors of the posterior fossa cannot be fully resected and are likely to recur without postoperative radiation. 2. Less common than medulloblastoma T - third most common paediatric brain tumour, after medulloblastoma & JPA. 3. Does not metastasize as frequently as medulloblastoma T - subarachnoid dissemination via CSF rare, observed in <10% of patients at diagnosis when ependymoblastomas are excluded. The incidence is higher with infratentorial ependymomas than with supratentorial tumors (9% vs 1.6%). 4. Myxopapillary variant in filum terminale T - considered a biologically and morphologically distinct variant of ependymoma, occurring almost exclusively in the region of the cauda equina and behaving in a more benign fashion than grade II ependymoma. 5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children.

Answer 83

* *LJS edit** new WHO grading - invasion into brain parenchyma makes it grade 2. So now 3. is also false https: //www.pathologyoutlines.com/topic/cnstumorwhomeningioma.html 2. Intra axial position F - Most common extra axial tumour. Derive from arachnoid cap cells (associated with dura mater, choroid plexus). Grow along external surface of brain or ventricular system. However, there are around 11 case reports of intraparenchymal meingiomas, believed to arise from arachnoid cells of the pia mater. [J Neurosurg (paeds) 2004] 22. Meningioma, which is least correct: (GC) 1. WHO class 1 T - vast majority are grade I. Grade II Atypical (5-15%); grade III Anaplastic (1%). 2. Intra axial position F - Most common extra axial tumour. Derive from arachnoid cap cells (associated with dura mater, choroid plexus). Grow along external surface of brain or ventricular system. However, there are around 11 case reports of intraparenchymal meingiomas, believed to arise from arachnoid cells of the pia mater. [J Neurosurg (paeds) 2004] 3. Invasion into brain parenchyma does not change grade T - Usually benign; not considered malignant even if invades bone and skeletal muscle. Grade II: invasion of dura, bone or soft tissue is not a feature. Grade III: invasive front is discrete or proceeds along vessels trapping gliotic areas, however, invasion alone is insufficient for diagnosis. 4. Papillary variant T - rare histological variant (grade III), tends to occur in children, histol shows papillae composed of syncytial cells making rosettes around vessels. Note that morphological types are: globular, en plaque, multicentric (<10%). [Path outlines, Dahnert] **LJS edit** new WHO grading - invasion into brain parenchyma makes it grade 2. So now 3. is also false

Answer 84

1. Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). 23. 15yo with psychosis, MRI showed diffuse WM abnormality, which is most likely: (GC) 1. Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). 2. ADEM F - multifocal punctate or large confluent areas of T2/FLAIR hyperintensity. 3. Huntington’s F - caudate nucleus atrophy. 4. HIV F - AIDS-dementia complex: cerebral atrophy, subtly increased SI on T2/FLAIR without mass effect (from leaky capillaries), may be focal/diffuse, symmetric/asymmetric, reversible/nonreversible. Symptoms are more of inattention, indifference and psychomotor slowing (progressing to frank dementia), i.e. not psychosis.

Answer 85

2. Caudate nucleus + putamen T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 24. Huntington’s chorea, what does it show: (GC) 1. Various locations including basal ganglia F - although the globus pallidus may secondarily atrophy, with dilatation of the lateral and third ventricles. 2. Caudate nucleus + putamen T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 3. Cerebellum F 4. Locus ceruleus F - involved in Parkinson's disease.

Answer 86

**LJS edit** - 60% cerebellum, optic pathways next most common. Others: brainstem, cerebral hemispheres, cord. I think 3 (brainstem) most common of the options given 1. Cerebrum Most lesions occur in or near the midline. Commonest locations: cerebellum, hypothalamus (around 3rd ventricle), optic n./chiasm. [RG 2004] 25. Pilocytic Astrocytoma, most common location: 1. Cerebrum 2. CPA 3. Brainstem 4. Hypothalamus 5. Pituitary

Answer 87

2. Wilson’s - T - Onset of liver diease with WD usually 8-16yo, neurological symtpoms rare <12yo. WD often recognised in 2nd-3rd decade. M=F. Most common to see putamen (predilection for outer rim) and pons (dorsal and central regions) of increased T2. 27. 25 yo man with liver failure, previously had MRI showing increased signal in basal ganglia, most likely: (T bag, G bees) 1. HIV - F 2. Wilson’s - T - Onset of liver diease with WD usually 8-16yo, neurological symtpoms rare <12yo. WD often recognised in 2nd-3rd decade. M=F. Most common to see putamen (predilection for outer rim) and pons (dorsal and central regions) of increased T2. 3. Liver failure kernicterus - F - develops during the 1st year of birth (term and pre-terms). Kernicterus is the staining of the basal ganglia, brainstem, and cerebellum by unconjugated bilirubin: encephalopathy due to deposition of toxic unconjugated bilirubin. High signal T2 in globus pallidus or other areas of basal ganglia. Most common cause = erythroblastosis fetalis. 4. Disseminated toxoplasmosis - F

Answer 88

c. Papillary variant 28. Craniopharyngioma on histology in a 60 yo, solid 5cm, no cystic change or calcification: (GC) a. Review pathology: not usually solid tumours F - vary from solid to cystic. b. Sellar expansion but not destruction F - extensive sellar destruction in 75% of craniopharyngiomas c. Papillary variant T d. Absence of calcification is unusual F - only 30-40% contain Ca2+ in adults, cf. 90% of CP in children. Craniopharyngiomas arise from epithelial remnants of Rathke’s pouch that are trapped in pituitary stalk. Grows slowly and damages hypothalamus (causing endocrine abnormalities), compresses optic chiasm (causing bitemporal hemianopsia), blocks third ventricle (causing hydrocephalus). Histologically benign but frequently recurs due to incomplete excision; rarely metastasizes or transforms to squamous cell carcinoma. * Papillary subtype: usually occurs in older adults (50+). Histology: well-circumscribed, composed of cores of fibrovascular stroma lined by well-differentiated squamous epithelium that may separate to form pseudopapillae; resembles squamous papilloma; no stellate reticulum, no “wet” keratin, no calcification, no xanthogranulomatous inflammation; cystic fluid does not resemble motor oil. * Adamantinomatous subtype: usually children (5-14yrs), associated with beta-catenin mutations. 90% cystic, 90% calcifn. Histol: wet keratin, Ca2+, cysts with cholesterol (sump oil).[Path outlines]

Answer 89

4. History of rheumatic fever and tooth extraction T - Aneurysms that develop at distal sites in the intracranial circulation are often caused by trauma or infection. Mycotic aneurysms are most commonly due to infected arterial embolus, occurring in subacute bacterial endocarditis. In such cases, they are often multiple, being situated in small corticomeningeal branches of the cerebral artery. 29. Peripheral MCA aneurysm, most likely history: (GC) 1. SLE F - Commonly reported CNS vascular lesions with SLE include infarcts and transient ischemic attacks. Intracranial hemorrhages are present in approximately 10% of patients with CNS symptoms. Although uncommon, arteritic and nonvasculitic aneurysms occur in SLE. These can be saccular, fusiform, or a bizarre-looking mixture of both. 2. Past history of irradiation for fibrous dysplasia F - Radiation is contraindicated as it has been found to increase the rate of secondary malignancy by 400 times. If in the remote past... intracranial aneurysms may develop (and rupture) post irradiation. 3. Hypertension F - Charcot-Bouchard microaneurysms secondary to segmental lipohyalinosis of the walls of long penetrating arteries. 4. History of rheumatic fever and tooth extraction T - Aneurysms that develop at distal sites in the intracranial circulation are often caused by trauma or infection. Mycotic aneurysms are most commonly due to infected arterial embolus, occurring in subacute bacterial endocarditis. In such cases, they are often multiple, being situated in small corticomeningeal branches of the cerebral artery.

Answer 90

4. Anaplastic astrocytoma F - central white matter of cerebrum, typically frontal & temporal lobes. 30. Which is not associated with brain cortical involvement: (GC) 1. DNET T - nodular cortical mass, background of cortical dysplasia; WHO grade I. 2. Oligodendroglioma T - most commonly involve cortex & subcortical WM, may have Ca2+, frontal >temp; WHO grade I. 3. Pleomorphic xanthoastrocytoma T - superficial supratentorial tumour that involves the leptomeninges, most commonly in the temporal lobe. WHO grade II, relatively high recurrence rate, malignant transformation in 20%. 4. Anaplastic astrocytoma F - central white matter of cerebrum, typically frontal & temporal lobes. 5. Ganglioglioma T - most common cause of chronic temporal lobe epilepsy; WHO grade I. Superficial gliomas: - glial neoplasms that are peripherally located and involve the cortical grey matter - commonly a seizure locus - amenable to surgical resection, with generally favorable prognosis - include: ganglioglioma, gangliocytoma, Lhermitte-Duclos (dysplastic cerebellar gangliocytoma), DNET, desmosplastic infantile ganglioglioma, pleomorphic XA. [RG 2001]

Answer 91

4. Neurofibrillary tangles in occipital region - NFT's are commonly found in the entorhinal cortex, as well as in pyramidal cells of hippocampus, amygdala, basal forebrain, raphe nuclei. Perhaps in advanced dementia there may be occipital cortex involvement (?). Posterior cortical atrophy (Benson's syndrome) and Balint's syndrome may be regarded as variants of AD, whereby deposition of neuritic plaques and NFT's are specifically revealed in the posterior cerebral areas (occipital cortex, visual cortex). [Acta Neuropathologica 1993]

Answer 92

3. 4 x > common than medulloblastoma 1. Ependymoma – which is false: (GC) 1. Poor prognosis T - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults (mainly spinal tumours) and only 14% in children (mainly intracranial tumours; 70% infra-, 30% supratentorial). 2. Have drop mets T - GEM POT. Subarachnoid dissemination via CSF is observed in <10% of patients at diagnosis when ependymoblastomas are excluded. The incidence is higher with infratentorial ependymomas than with supratentorial tumors (9% vs 1.6%). 3. 4 x > common than medulloblastoma F - third most common paediatric brain tumour, after medulloblastoma & JPA. 4. 4th ventricle T - In children, approximately 90% of ependymomas are intracranial - 70% infratentorial (usually arising from roof of 4th ventricle), 30% supratentorial. In adults and adolescents, 75% arise within the spinal canal. [eMedicine, Adelaide notes]

Answer 93

**LJS edit** 4th V most common site Often incidental finding at imaging/autopsy, WHO 1, can have surveillance rather than resection. I think 1 is more correct than 4. **agree with above as per Big Robbins 8th (pg 1311) + radiopaedia (RY). Subependymoma (TW) 1. Usually slow growing and asymptomatic - F - slow growing, however, although can be asymptomatic, 50% become symptomatic. WHO grade I. **Big Robbins/radiopaedia - often incidental at autopsy/imaging. Hence T not F (RY). 2. Associated with TS - F - TS assoc with cortical / subcortical tubers, subependymal hamartomas, subependymal GCA. Zits, fits, nitwits (facial angiofibroma, epileptic seizures, mental retardation). 3. 5-10 yo - F - middle-aged / elderly adult (typically 40-50yo). Rare in children (unlike ependymoma). 4. Commonly in lateral ventricle - T - inferior fourth ventricle, frontal horn of lateral ventricle most common sites. **radiopaedia = 4th vent 50-60%, lat vent 30-40% (RY).

Answer 94

* LW: 3. ADEM - T 3. MS plaques that are not perpendicular to ventricles or some such (atypical anyway) (TW) 1. Type III, IV: Describes active plaques that are less well demarcated with widespread oligodendrocyte deposits (pattern 3) and are note centered on vessels with central only oligodendeocyte deposits (pattern 4). Pattern 1 - active plaque sharply demarcated and centered on blood vessel with deposition of immunoglobulin and complement. Pattern 2 - active plaque sharply demarcated and centered on blood vessel without deposition of immunoglobulin or complement. 2. Devics - - AKA neuromyelitis optica - combination of bilateral optic neuropathy and transvers myelitis. Optic neuritis can occur concurrently, or one may follow the other. Diagnostic criteria for NMO - optic neuritis, myelitis, and one of the following: MRI evidence of a contiguous spinal cord lesion 3 or more segments in length, or seropositivity for NMO IgG. Although original diagnostic criteria for NMO didn't permit CNS involvement (beyond optic nerves and spinal cord), revised criteria allow for other brain lesion in patients who otherwise meet criteria for NMO. 3. ADEM - T 4. Typical of MS - F - typical is plaxues perpendicular to ventricles / callososeptal interface.

Answer 95

1. Fat fluid level and satellite lesion suggests demyelination

Answer 96

1. Endarteritis causes ischaemia. T - ischaemic infarcts of BG + internal capsule in 20-40%, due to vascular compression and/or occlusion of small perforating vessels in basal cisterns.

Answer 97

3. Commonly cortical F - most lesions occur in or near the midline, usually arising from the cerebellum, optic n/chiasm, hypothalamic-thalamic region. **LJS - cerebellar hemisphere most common location (60%) then optic pathway. Does "cortical" mean cerebral cortex or include cerebellar cortex?

Answer 98

1. Fatty accumulation – ?T – denervation – fatty replacement With ALS the increasing signal in muscle is due to (TW) 1. Fatty accumulation – ?T – denervation – fatty replacement 2. Deposition of lipofuscin – F – lipofuscin deposition in the motor neurons

Answer 99

3. Neuropathic – T – neuropathic joint. Loss of proprioception and vibration sense, but preservation of temperature and sensation. So I guess painful Charcot joint. Autosomal recessive degenerative disorder. Most common hereditary ataxia. Primary affects CNS, spinal cord, and peripheral nerves, as well as the heart and pancreas. Most cases caused by loss of function mutations in frataxin gene. Early loss of position and vibration sense and reflects posterior column spinal cord dysfunction as well as dorsal root and peripheral, primarily sensory, axonal neuropathy. Pain and temperature sensation are retained.

Answer 100

3. Lysosomal storage disorder – F – mitochondrial disorder characterised by neurodegeneration. Brain and striated muscle highly dependent on oxidative phosphorylation which are moste severely affected in mitochondrial disorders. . Leighs, which is incorrect… (TW) 1. Increased T2 signal in peri-aqueductal gray matter – T – best diagnostic clue = bilateral, symmetric increased T2/FLAIR in putamina and peri-aqueductal gray matter 2. Enhancement is uncommon - T 3. Lysosomal storage disorder – F – mitochondrial disorder characterised by neurodegeneration. Brain and striated muscle highly dependent on oxidative phosphorylation which are moste severely affected in mitochondrial disorders. 4. May be x-linked inheritance – Autosomal recessive, X-linked, and maternal inheritance of mutated proteins involved in mitochondrial energy production underlie Leigh syndrome. 5. Most present by 2y age – T – majority by 2yo.

Answer 101

LW: likely incomplete recall: > 80% of acromegaly due to pituitary GH release. Rare case reports of Phaeochromocytomas secreting GHRH and resulting in acromegaly. Not in Robbins. Hence incidentaloma is favoured option, as they are relatively common, and unlikely related to acromegaly in the provided details. While a met or adenocarcinoma of adrenal gland wont / unlikely to secrete GH or GHRH to cause acromegaly . incidental adenoma – T – most likely. Incidental adenomas found in 1-2% of population. 10. acromegaly 3cm adrenal lesion likely a (TW) 1. met – F – no reason to suspect mets 2. adenocarcinoma – F – adrenal carcinoma rare. 3. incidental adenoma – T – most likely. Incidental adenomas found in 1-2% of population. Acromegaly – excess growth hormone due to eosinophilic adenoma / hyperplasia in anterior pituitary.

Answer 102

2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain.

Answer 103

1. Hippocampus 2. Least likely site for hypertensive bleed in the brain is: (GC) 1. Hippocampus T 2. Cerebellum F - 10%; behave like SOL's - herniation & obstructive hydrocephalus. 3. Basal ganglia F - with thalamus account for 65% of hypertensive bleeds 4. Thalamus F - see above 5. Brainstem F - 10%

Answer 104

1. Detectable at angiography F - most are angiographically occult due to slow flow.

Answer 105

1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation

Answer 106

1. Oligodendroglioma

Answer 107

4. Dandy Walker 6. Which is least likely to involve the corpus callosum: (GC) 1. GBM T - most commonly spread via direct extension along WM tracts, including the CC - classic butterfly pattern. 2. Marchifava Bignami T - primarily affects the CC - acute form affects the genu & splenium, chronic form affects the body. 3. DAI T - classic triad of GW junction, dorsolateral brainstem, and CC (most commonly eccentrically and in the splenium). 4. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) 5. Lymphoma T - differ from GBM as usually less peritumoral oedema, less often necrotic, highly radiosensitive, frequently respond dramatically to steroids. [AJR 2002]

Answer 108

2. Lewy bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease.

Answer 109

2. Angioneogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 8. PNET, which is the most typical appearance: 1. Cortical F - deep cerebral white matter, most commonly frontal lobe. 2. Angioneogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 3. Cystic - Eric had this as the answer in 2004 - F - large (hemispheric) heterogeneous mass with tendency for necrosis (65%), cyst formation, calcification (71%), haemorrhage (10%). 4. Vasogenic oedema F - thin rim of oedema 5. Astrocytoma

Answer 110

* AJL - I favour chicken pox to not be a congenital infection, it is never mentioned in robbins. The rest are counted as TORCH (Toxo, other (syphilis, ...), Rubella, CMV, Herpes). 5. Herpes - In utero infection is rare; 3% of these will have severe symptoms of skin vesicles/scarring, eye disease, microcephaphaly/hydranencephaly. HSV-2 is most commonly acquired during vaginal delivery (intrapartum), can also occur postnatally (horizontal transmission). 9. Which of the following is not a congenital CNS infection: (GC) see Aug 2007 1. Chicken pox Eric had this as the answer in 2004 - Dahnert includes it in "Other", p232.? T - Congenital varicella syndrome occurs in 2% of children born to women who develop varicella during the 1st or 2nd trimester of pregnancy. Manifests as IUGR, cortical atrophy, microcephaly, microphthalmia, cataracts, limb hypoplasia, skin scarring. 2. Rubella 3. CMV 4. Toxoplasmosis 5. Herpes - In utero infection is rare; 3% of these will have severe symptoms of skin vesicles/scarring, eye disease, microcephaphaly/hydranencephaly. HSV-2 is most commonly acquired during vaginal delivery (intrapartum), can also occur postnatally (horizontal transmission).

Answer 111

Perivenular inflammation T - at junction of pial veins 10. Multiple sclerosis, distribution: (GC) a. Ovoid lesions with long axis oriented parallel to ventricular walls F - perpendicular, aka Dawson's fingers. b. Subcortical U fibres spared F - not spared, 10% of MS plaques occur in grey matter. c. 40% of spinal lesions occur without coexistent intracranial plaques F - 12-33% d. Perivenular inflammation T - at junction of pial veins e. Predilection for thoracic cord F - cervical cord [Dahnert]

Answer 112

Haemorrhage is uncommon – T – rare to get haemorrhagic foci (0.5%). 1. Regarding vestibular schwannomas: (TW) 1. Bilateral tumours are associated with NF1 – F – NF2 = MISME, multiple inherited schwannomas, meningiomas, and Ependymomas. 2. Haemorrhage is uncommon – T – rare to get haemorrhagic foci (0.5%). 3. About 70% are cystic – F – 15% have intramural cysts (Harnsberger) 4. Meningeal reaction is typical – F – this is a differentiating factor to Dx from meningioma. 5. A melanotic variant is a recognized entity – F - CME says F. However there are a handful of cases reported (so very, very rare). Melanotic schwannoma is a rare melanin-producing nerve sheat tumor. MSs are of neural crest origin, prob from neoplastic proliferation of a common precursor cell for both Schwann cells and melanocytes. Most involve cranial or spinal nerve roots (esp spinal Cx and thoracic nerves). 10% involve symp chain. There have been reports of MSs of vestibular nerves. MSs may be component of Carney complex.

Answer 113

1. Type 2 neurofibromatosis is associated with multiple schwannomas – T – MISME, multiple inherited schwannomas, meningiomas, Ependymoma. 2. The following are true in relation to cerebello-pontine angle tumours:¬ (TW) 1. Type 2 neurofibromatosis is associated with multiple schwannomas – T – MISME, multiple inherited schwannomas, meningiomas, Ependymoma. 2. Acoustic neuromas are typically hyperintense on TI weighted images – F – intermediate signal most common. High signal patches if rare haemorrhagic lesion present. 3. Peripheral enhancement is a feature of epidermoid cysts – F – no enhancement is the rule, however sometimes the margin of cyst minimally enhances CECT. Mild peripheral enhancement occurs in approx 25% cases. Osborn. 4. Choroid plexus seen in the cerebello-pontine angle is not a normal feature – F – choroid plexus may normally pass from 4th ventricle through foramen of Luschka in to CPA cistern. Osborn. 5. Acoustic neuromas arise from the cochlear portion of the acoustic nerve – F – arise from the vestibular segment of CN VIII, with an equal frequency b/w superior and inferior vestibular nerves. Cochlear nerve involvement is much less common (15% vs 85%).

Answer 114

2. Is associated with Down’s syndrome – F – Assoc with abnormal karyotype (T13, 15, 18 – not typically assoc with T21, however there are some case reports). Multiple other assoc: Dandy-Walker cyst, interhemispheric arachnoid cyst, hydrocephalus, intracerebral lipoma of CC, AC II malformation, porencephaly, Holoprosencephaly, polymicrogyria. 3. The following statements regarding agenesis of the corpus callosum, false?: (TW) 1. Ventriculomegaly predominantly affects the occipital horns – T – occipital horns often dilated (colpocephaly). Pointed frontal horns. Can get dilation of the posterior temporal horns in the absence of splenium. 2. Is associated with Down’s syndrome – F – Assoc with abnormal karyotype (T13, 15, 18 – not typically assoc with T21, however there are some case reports). Multiple other assoc: Dandy-Walker cyst, interhemispheric arachnoid cyst, hydrocephalus, intracerebral lipoma of CC, AC II malformation, porencephaly, Holoprosencephaly, polymicrogyria. 3. The lateral ventricles are widely placed – T- “bat-wing” appearance of lateral ventricles (= wide separation of lateral ventricles with straight parallel parasagittal orientation with absent callosal body) 4. There is an association with heterotopic gray matter – T – polymicrogyria, gray-matter heterotopia 5. It is associated with colpocephaly - T

Answer 115

contrast enhancement of the para hippocampal gyrus - F – no enhancement. 1) Mesial temporal sclerosis, which is false (TW) 1. contrast enhancement of the para hippocampal gyrus - F – no enhancement. 2. atrophy hippoc gyrus – T – decreased size of hippocampus 3. may see fornix and/or mamillary body atrophy – T – location: mesial temporal lobe – hippocampus > amygdale > fornix > mamillary bodies. Bilateral in 20% cases. 4. dilatation of temporal horn may be evident - T

Answer 116

4. 15% malignant - ?T - in the literature the percentage of the anaplastic variant ranges from 7-89% (Med and Ped Onc: 1998 30:6 p319). 2) ependymoma in the pediatric patient (TW) 1. supratentorial location - F - infratentorial 70% (floor 4th ventricle). Can also occur supratentorial: frontal > parietal > temporoparietal > juxtaventricular. 2. homogenous enhancement - F - variable heterogeneous enhancement. 3. hemorrhage is common - F - intratumoral haemorrhage 10% 4. 15% malignant - ?T - in the literature the percentage of the anaplastic variant ranges from 7-89% (Med and Ped Onc: 1998 30:6 p319). 5. arise from lumbar nerve roots in the spine - F - arise form ependymal cells lining the central canal.

Answer 117

normal sella favours meningioma rather than macroadenoma - T - as pituitary MAs grow they first expand sella and then grow upwards. Aggresive adenomas extend inveriorly, invade sphenoid, and may destroy upper clivus. As they are soft - often are indented by diaphragma sellae giving them a 'snowman' configuration which can help Dx from meningoma. ) Sellar lesions, which is true (TW) 1. normal sella favours meningioma rather than macroadenoma - T - as pituitary MAs grow they first expand sella and then grow upwards. Aggresive adenomas extend inveriorly, invade sphenoid, and may destroy upper clivus. As they are soft - often are indented by diaphragma sellae giving them a 'snowman' configuration which can help Dx from meningoma. 2. squamous variant of craniopharyngioma is more likely cystic - F - squamous papillary type (more common in adults) rarely calcifies, often solid, isodense. Both adamantinomatous and squamous papillary types enhance. 3. intrasellar arachnoid cyst will displace stalk anteriorly - F - 10% arachnoid cysts are suprasellar & would push stalk back. 4. 17mm pituitary is normal for pregnant female - F - normal pituitary measurements: children 6mm, males and post-menopausal females 8mm, young menstruating females 10mm, pregnant/lactating females 12mm. 5. macroadenoma more likely to compress ICA than meningioma - F- meningioma more likely to compress / constrict ICA (given ICA course in cavernous sinus too). Note that macroadenomas can also extend into the cavernous sinus.

Answer 118

3. sudden loss after minor trauma is typical for vestibular aqueduct synd - T ) Sensorineural hearing loss, which is true (TW) 1. destruction of ossicular chain from otitis media - F - conductive 2. cochlear SNHL is more common than retrocochlear SNHL - F - other way around. retrocochlear SNHL (abnormalities of neurons of the spiral ganglion) more common than cochlear SNHL (damage to cochlea / organ or Corti). Dahnert 6th. 3. sudden loss after minor trauma is typical for vestibular aqueduct synd - T

Answer 119

4. spinal drop mets most likely posterior - T - normal flow of CSF from cisterna magna - highest concentration of potential tumor cells. 5) CME Medullo (TW) 1. resistant to XRT - F - highly radiosensitive. Rx with surgery and XRT. 2. ca2+ is most important differentiator from astro on CT - F - calcification is present in up to 20% in both MB and PCA. 3. desmoplastic in <3y - F - MB in adult patients often the desmoplastic histologic subtype (and are prone to recurrence). 4. spinal drop mets most likely posterior - T - normal flow of CSF from cisterna magna - highest concentration of potential tumor cells. 5. majority are lytic bone metastases - F - osseous lesions are usually sclerotic (65% sclerotic, 35% lytic). Bone is most common extraneural metastatic site.

Answer 120

2. enhancement lasts 3 months - T - Dahnert says Gd-DTPA enhancement of lesions on T1WI up to 8weeks following acute demyelination. Osborn says >90% of enhancing lesions disappear within 6 months. MS (TW) 1. juxta cortical favours MS vs age - F - calloseptal favors MS, plus infratentorial. 2. enhancement lasts 3 months - T - Dahnert says Gd-DTPA enhancement of lesions on T1WI up to 8weeks following acute demyelination. Osborn says >90% of enhancing lesions disappear within 6 months. 3. usually thoracic spinal lesion - F - predilection for cervical cord 4. perpendicular to long axis - F - parallell to long axis of spinal cord / perpendicular to the axis of CC, ventricles.

Answer 121

2. large acetabular angles - F - flattening of acetabular roof (small acetabular angle). Flaring of iliac wings "mickey mouse ears" / " elephant ears". Decreased iliac angle. 8) Downs, false (TW) 1. hypotelorism - T - also have hypoplasia of sinuses and facial bones 2. large acetabular angles - F - flattening of acetabular roof (small acetabular angle). Flaring of iliac wings "mickey mouse ears" / " elephant ears". Decreased iliac angle. 3. brachycephaly - T - microcrania. 4. metaphyseal flaring - T

Answer 122

. cingulate gyrus normal - F - dysgenesis of cingulate gyrus / persistent eversion of cingulate gyrus 9) CC dysgenesis, false (TW) 1. genu always present in partial - T - depending on time of arrested growth (anteroposterior development of genu, body, splenium, however, rostrum forming last). Can have: genu only, genu + part of body, genu + entire body, genu + body + splenium (without rostrum). 2. cingulate gyrus normal - F - dysgenesis of cingulate gyrus / persistent eversion of cingulate gyrus 3. medial parietal sulci affected - T - radial array pattern of medial cerebral sulci, gyri "point to" 3rd ventricle 4. foramen monro enlarged - T - enlarged / elongated foramina of Munro 5. assoc with AC II - T - 7%. Also assoc with DW cyst, interhemispheric arachnoid cyst, hydrocephalus, lipoma of CC, porencephaly, holoprosencephaly, polymicrogyria. CC segments (front to back): Lamina rostralis (unmyelinated), Rostrum, Genu, Body / isthmus, Splenium (myelinated). * Presume AC II = Arnold-Chiari type II malformation

Answer 123

2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. . BBB, which is incorrect: (GC) 1. Water soluble medium cannot pass if normal BBB T - solutes with high affinity for plasma water, low affinity for plasma proteins, and high extremely low partition coefficients do not penetrate normal BBB (eg. contrast media). 2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. 3. Capillaries are continuous T - this is the basis of the BBB. Other types are fenestrated (circumventricular organs), and sinusoidal (liver, spleen, bone marrow). 4. Continuous capillaries have no fenestrations T - wall is composed of a single layer of endothelial cells connected by tight junctions, surrounded by a continuous basement membrane. It is the continuity of the interendothelial tight junctions, lack of pinocytosis and absence of fenestrations that contribute to the restricted permeability of the BBB. 5. Tight junctions are important T - see above.

Answer 124

2. Detectable at angiography F - most are angiographically occult due to slow flow. 2. Cavernous angiomas, which is not typical: (GC) 1. Detectable at angiography F - most are angiographically occult due to slow flow. 2. Bleeding tendency T - nearly all show evidence of recent and remote hemorrhage, as suggested by the presence of hemosiderin-laden macrophages, cholesterol crystals, and hemosiderin-stained parenchymal tissues. 3. No intervening normal brain T - this is the only histopathologic characteristic that distinguishes these lesions from capillary telangiectasias. 4. Associated venous angioma T - persistent elevations in venous pressures, as may be seen locally within a venous malformation, may promote a pathologic reactive angiogenesis or angiogenic proliferation, resulting in abnormal blood vessel growth and coalescence. Note that it is the immaturity of the blood vessels within the cavernoma that differentiates it from a venous angioma (which consists of mature vessels responsible for normal venous drainage). 5. Pseudocapsule T - clots and blood products of various stages of evolution within the lesion, as well as calcification and gliosis surround the cavernoma, creating the appearance of a pseudocapsule. (eMedicine)

Answer 125

Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 3. Which is the most important for diagnosis in GBM: (GC) 1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 2. Angiogenesis ? - microvascular proliferation is also a Dx feature 3. Cystic change F - non specific feature 4. Mitosis F - abnormal mitoses are also present in grade III (anaplastic) astrocytoma 5. Vasogenic oedema F - non specific feature WHO grading & Histological criteria: I Pilocytic astrocytoma - II Diffuse astrocytoma - 1 criterion, usually nuclear atypia III Anaplastic astrocytoma - 2 criteria, usually nuclear atypia and mitoses IV Glioblastoma - 3 criteria, usu nuclear atypia, mitoses, microvasc proliferation +/or necrosis

Answer 126

. Lewy bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease. 4. Which is not a feature of Alzheimer’s: (GC) 1. Hirano bodies T - elongated glassy eosinophilic bodies of paracrystallline arrays of beaded filaments predominantly of actin, found mostly in hippocampal pyramidal cells in AD. 2. Lewy bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease. 3. Senile plaques T - aka neuritic plaques; focal spherical collections of dilated tortuous silver-staining neuritic processes (dystrophic neurites) surrounding a central amyloid core. 4. Neurofibrillary tangles T - bundles of filaments in cytoplasm of neurons that displace or encircle the nucleus, 'flame-shaped', seen well with silver staining (especially in cortical neurones). Characteristic but not specific to AD; also seen in PSNP, postencephalitic PD, ALS-parkinsonian-dementia complex of guam (!) 5. Amyloid T - almost an invariable accompaniment of AD. Beta-amyloid and its precursor protein (APP) are implicated in the aetiopathogenesis. Nash:- NFT- amyloid- senile plaque- hiring body

Answer 127

5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children. 5. Children with Ependymoma, which is false: (GC) 1. Prognosis poor – cannot remove completely T - Despite the survival advantage of gross total resection, lesions of the posterior fossa are in close proximity to cranial nerves with a significant risk of long-term neurologic dysfunction and disability. Hence, most tumors of the posterior fossa cannot be fully resected and are likely to recur without postoperative radiation. 2. Less common than medulloblastoma T - third most common paediatric brain tumour, after medulloblastoma & JPA. (Adelaide notes) 3. Does not metastasize as frequently as medulloblastoma T - subarachnoid dissemination via CSF rare, observed in <10% of patients at diagnosis when ependymoblastomas are excluded. The incidence is higher with infratentorial ependymomas than with supratentorial tumors (9% vs 1.6%). 4. Myxopapillary variant in filum terminale T - considered a biologically and morphologically distinct variant of ependymoma, occurring almost exclusively in the region of the cauda equina and behaving in a more benign fashion than grade II ependymoma. 5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children. In children, approximately 90% of ependymomas are intracranial - 70% infratentorial (usually arising from floor of 4th ventricle), 30% supratentorial. In adults and adolescents, 75% arise within the spinal canal. [eMedicine, Adelaide notes]

Answer 128

Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). . 15yo with psychosis, MRI showed diffuse WM abnormality. Which is most likely: (GC) 1. Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). 2. ADEM F - multifocal punctate or large confluent areas of T2/FLAIR hyperintensity. 3. Huntington’s F - caudate nucleus atrophy. 4. HIV F - AIDS-dementia complex: cerebral atrophy, subtly increased SI on T2/FLAIR without mass effect (from leaky capillaries), may be focal/diffuse, symmetric/asymmetric, reversible/nonreversible. Symptoms are more of inattention, indifference and psychomotor slowing (progressing to frank dementia), i.e. not psychosis. (Dahnert, Pocket Rad paeds neuro)

Answer 129

2. Caudate nucleus T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 7. Huntington’s chorea, what does it show: (GC) Autosomal dominant with complete inheritance, increased CAG trinucleotide repeats in huntingtin gene located on chromosome 4. 1. Various locations including basal ganglia F - although the globus pallidus may secondarily atrophy, with dilatation of the lateral and third ventricles. 2. Caudate nucleus T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 3. Brainstem and Cerebellum F 4. Locus ceruleus, amygdala and basal ganglia F 5. Substantia nigra F - Parkinson's disease: pallor of the substantia nigra and locus ceruleus, Lewy bodies microscopically. [Robbins, Dahnert]

Answer 130

4. Hypothalamus Most lesions occur in or near the midline. Commonest locations: cerebellum, hypothalamus (around 3rd ventricle), optic n./chiasm. In adults the tumour more frequently occurs in the cerebral hemisphere. Of all patients with an optic pathway glioma, 1/3 have NF-1, and of all tumours in this region 40-70% occur in NF-1 patients. [RG 2004]

Answer 131

c. Commonly cortical. F - most lesions occur in or near the midline, usually arising from the cerebellum, optic n/chiasm, hypothalamic-thalamic region. 53. Juvenile pilocystic astrocytoma, which is false? (GC) a. Even without surgery rarely fatal. T - WHO grade I, 10YS rate of up to 94%, 20YS 79%. b. Well circumscribed, easy to cut out. T - surgery generally regarded as curative when gross total resection attained. Resection of the mural nodule is the key surgical objective, since the surrounding cyst occurs as a simple reactive change in most cases (however, neoplastic changes in the cyst wall have been documented). Although most appear well-circumscribed macroscopically, they may infiltrate into the surrounding parenchyma for several mm. XRT is strictly avoided - significant morbidity in <5yo. and no clinical proof of preventing recurrence. c. Commonly cortical. F - most lesions occur in or near the midline, usually arising from the cerebellum, optic n/chiasm, hypothalamic-thalamic region. d. More benign behaviour when it occurs in patient with NF1 T - Only a small number of NF1 patients showed tumour progression 10yrs after diagnosis; and those with an optic pathway glioma had a longer interval btn primary dx and first recurrence cf. those without NF1. e. Abundant Rosenthal fibres T - classically biphasic - loose glial component, and compact piloid tissue (dense sheets of bipolar cells with fine fibrillary processes, abundant RF's). Rosenthal fibres are also seen in areas of longstanding brain gliosis.[RG 2004]

Answer 132

a. Endarteritis causes ischaemia. T - ischaemic infarcts of BG + internal capsule in 20-40%, due to vascular compression and/or occlusion of small perforating vessels in basal cisterns. 56. TB Meningitis, which is most correct: (GC) Bacilli seed to meninges, form small subpial/subependymal caseous foci. These Rich foci then rupture into SAS (if located deeper in brain will cause tuberculomas/asbcesses). a. Endarteritis causes ischaemia. T - ischaemic infarcts of BG + internal capsule in 20-40%, due to vascular compression and/or occlusion of small perforating vessels in basal cisterns. b. Small multiple miliary nodules in brain. T - but is an association, ie. miliary TB is usually associated with TB meningitis. Tuberculomas may be solitary (70%), multiple, or miliary. Seen in AIDS patients, infants + small children. c. Cannot be seen macroscopically. F - thick gelatinous exudate. d. Can be asymptomatic. F - usually the prodrome is non specific; symptoms include headache, vomiting, photophobia, fever, drowsiness, meningism and confusion, occurring over a period of 2-3wks. Fever and headache can be absent in 25%, malaise absent in up to 60%. Headache and mental state changes more common in elderly patients.[eMedicine, Dahnert, RG 2007]

Answer 133

a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial 58. Autopsy of the thyroid in Hashimotos shows? (TW) a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial cells with abundant eosinophilic, granular cytoplasm, termed Hurthle cells. b. Fibrosing nodules - F - Reidel's thyroiditis. c. Psammoma bodies - F - in papillary thyroid carcinoma. Concentrically calcified structures.

Answer 134

c. Bilateral or unilateral enlarged lobes - T - gland may be unilaterally or bilaterally enlarged and firm, with an intact capsule. Both thyroid lobes are involved from the beginning in most patients. 59. Macroscopic features of de Quervains Thyroiditis (AKA subacute). (TW) a. Diffuse smooth symmetrical goiter - F - only mild-moderate enlargement (Dahnert, UptToDate), patchy with occasionally distinctly focal inlvolvement. On cut section - involved areas are firm and yellow-white and stand out from the more rubbery, normal brown thyroid substance. b. Multiple nodules - F - early scattered follicles may be entirely disrupted and replaced by PMN forming microabscesses. Later the characteristic changes: aggregates of cells around damaged follicles .c. Bilateral or unilateral enlarged lobes - T - gland may be unilaterally or bilaterally enlarged and firm, with an intact capsule. Both thyroid lobes are involved from the beginning in most patients.

Answer 135

b. Warthins tumour - T - benign neoplasm. Distinctive double layer of lining cells with surface palisade of columnar cells having abundant, finely granular, eosinophilic cytoplasm, imparting an oncocytic appearance, resting on a layer of cuboidal to polygonal cells. 60. 55 yr old man with oncocytes from biopsy of a solitary parotid cyst? (TW) a. Benign pleomorphic adenoma - F - heterogeneity. Epithelial elements resembling ductal cells or myoepithelial cells disposed in duct formations, acini, irregular tubules, strands, or sheets of cells. b. Warthins tumour - T - benign neoplasm. Distinctive double layer of lining cells with surface palisade of columnar cells having abundant, finely granular, eosinophilic cytoplasm, imparting an oncocytic appearance, resting on a layer of cuboidal to polygonal cells. c. HIV. d. Type 1 Branchial cleft cyst - F - fibrous walls usually lined by stratified squamous or pseudostratified columnar epithelium underlaid by an intense lymphcytic infiltrate or, more often, well-developed lymphoid tissue with reactive follicles. e. Mucoepidermoid - F - mucus secreting cells, often forming glandular spaces. Higher grade tumors are composed of squamous cells with only a scatterin gof mucus-secreting cells.Oncocytes are epithelial cells stuffed with mitochondria that impart the granular appearance to the cytoplasm.

Answer 136

d. Riedels Thyroiditis - F - rare, chronic inflammatory disease of thyroid gland characterized by a dense fibrosis that replaces normal thyroid capsule. Morbidity is most frequently related to local compressive symptoms. Most patients are euthyroid, and hypothyroidism can be seen in 30% cases. 61. Least likely to cause Hyperthyroidism? (TW) a. Graves disease - T - thyroid stimulating antibodies. Elevated T3 and T4. b. Toxic adenoma - T - AKA Plummer disease / toxic autonomous nodule. Hyperthyroidism caused by one / two hyperfunctioning nodules independent of normal pituitary-thyroid control. c. Hashimotos thyroiditis - T - thyrotoxicosis in early stage 4%. Hypothyroid at presentation 20%. Chronic lymphocytic thyroidits. Autoimmune process with marked familial predisposition. d. Riedels Thyroiditis - F - rare, chronic inflammatory disease of thyroid gland characterized by a dense fibrosis that replaces normal thyroid capsule. Morbidity is most frequently related to local compressive symptoms. Most patients are euthyroid, and hypothyroidism can be seen in 30% cases. e. Subacute thyroiditis - T - AKA subacute thyroiditis. Hyperthyrodisim 50% secondary to severe destruction. Short-lived hypothyroidism (25%) due to hormone depletion of gland. Probably viral aetiology. Lymphocytic infiltration, granulomatous and foreign body giant cells.

Answer 137

b. Paragangliomas are parasympathetic tumours - F - rare neuroendocrine tumors arising from paraganglionic tissue found between base of skull and floor of pelvis. Adrenal paraganglioma = phaeochromocytoma, extraadrenal paraganglioma sympathetic / parasympath **LJS - agree, paragangliomas can be SNS or PSNS 62. Which of the following is false? (TW) a. Chordomas arise from physaliphorous cells - T - arise from embryonic remnants of the primitive notochord. Microscopically, cordomas are composed of characteristic mucoid, fluid-containing, translucent cells of variable size with a large, intracytoplasmic vacuole, and they are rich in mucin and glycogen (physaliphorous cells) b. Paragangliomas are parasympathetic tumours - F - rare neuroendocrine tumors arising from paraganglionic tissue found between base of skull and floor of pelvis. Adrenal paraganglioma = phaeochromocytoma, extraadrenal paraganglioma sympathetic / parasympath c. Cholestrol granulomas need an aerated pterous apex for formation - T - results from obsturction of the normal aeration of petrous air cells. d. Cholestatomas arise from epithelial rests - T - derived from aberrant embryonic ectodermal rests in temporal bone (primary, AKA epidermoid cyst). Ingrowth of squamous epithelium throught tympanic membrane secondary to repeated inflammation / marginal perforation of ear drum.

Answer 138

d. Adrenal tissue under the renal capsule is an example of a choristoma- T - normal cells or tissues in an abnormal location. 63. Which of the following are true in regards to choristomas and hamartomas? (TW) a. A hamartoma is an ectopic rest of tissue- F - Tumor-like malformation with tissues of a particular part of the body arranged haphazardly, usually with excess of one or more of its components. Excessive but focal overgrowth of cells and tissues native to the organ in which it occurs (cf teratoma - tissues NOT specific to the part) b. A choristoma is abnormal tissue in a normal location - F - AKA heterotopia. Normal cells or tissues that are present in abnormal locations. eg rest of pancreatic tissue found in the wall of the somtach or small intestine, or small mass of adrenal cells found in the kidney, lungs, ovaries, or elsewhere. The heterotopic rests ore usually of little significance, but can be confused clinically with neoplasms. c. An adenoma is a typical hamartoma - F - adenoma is a benign tumor of glandular origin d. Adrenal tissue under the renal capsule is an example of a choristoma- T - normal cells or tissues in an abnormal location. e. Hamartomas predispose to an increased risk of malignant transformation - F - not neoplastic. No tendency to excessive growth, being co-ordinated with surrounding tissues and stops after adolescence.

Answer 139

2. Liquefactive - T - characteristic of focal bacterial or occasional fungal infections, as these agents constitute powerful stiumli to the accumulation of inflammatory cells. Hypoxic death of CNS cells often evokes liquefactive necrosis. Liquefactin completely digests the dead cells. Tranformation of tissue into liquid viscous mass. Which form of necrosis is seen with cerebral infarction (TW) 1. Coagulative - F - implies preservation of the basic outline of coagulated cell for a span of at least some days. Myocardial infact is typical example - ultimatley the necrotic myocardial cells are removed by fragmentation and phagocytosis of cellular debirs by scavenger cells and lysosomal enzymes. This type of necrosis is characteristic of hypoxic death of cells in all tissues except the brain. 2. Liquefactive - T - characteristic of focal bacterial or occasional fungal infections, as these agents constitute powerful stiumli to the accumulation of inflammatory cells. Hypoxic death of CNS cells often evokes liquefactive necrosis. Liquefactin completely digests the dead cells. Tranformation of tissue into liquid viscous mass. 3. Caseous - F - distinctive form of coagulative necrosis. Most often in foci of tuberculous infection. 4. Gummatous - F- restricted to necrosis involving spirochaetal infections (syphilis)

Answer 140

3. Lymphocytic infiltration - T - lymphocytic hypophysitis. Peripartum female (almost exclusively) with headache, multiple endocrine deficiencies. Idiopathic inflammation of anterior pituitary gland. Rare 1-2% of sellar lesions. 1. 28 yo F 6/52 post partum, hypopituitarism, likely (TW) 1. Empty sella - F - primary empty sella (10% incidence). Usually symptomoatic. 2. Pituitary carcinoma - F - rare! 3. Lymphocytic infiltration - T - lymphocytic hypophysitis. Peripartum female (almost exclusively) with headache, multiple endocrine deficiencies. Idiopathic inflammation of anterior pituitary gland. Rare 1-2% of sellar lesions. 4. Sheehan syndrome - F - *AJL - infarction and haemorrhage occuring peripartum secondary to blood volume loss (anterior pituitary susceptible due to low volume blood flow). Rare in developed countries due to improved care. I think this could be a correct answer for this but is more rare than lymphocytic hypophysitis therefore not the 'most correct'...

Answer 141

1. Amyloid angiopathy - T - usually lobar. Older patients. Usually >70yo, normotensive, demented. 6. Atypical of basal ganglia lesion: (TW) 1. Amyloid angiopathy - T - usually lobar. Older patients. Usually >70yo, normotensive, demented. 2. Fahrs disease - F - Bilateral symmetric basal ganglia Ca+ on CT. Location: globus pallidus is most common site of Ca+ (lateral pallidum > medial pallidum). Other areas may include putamen, caudate nuclei, thalami, cerebellum (esp dentate nuclei), cerebral white matter, internal capsule. 3. CO poisoning - F - Globus pallidi is most common site of abnormality. Hypodensity in GP on UECT. T1 hypointensity (necrosis) and hyperintensity (hemorrhage) reported. T2 hyperintensity with hypintense rim (prob due to hemosiderin). 4. Hypertensive haemorrhage - F - striatocapsular (putamen/ext capsule) 60-65%, Thalamus 15-25%, pons / cerebellum 10%.

Answer 142

*LW: See prior path / RD same question, both bacterial ADEM and demyelination are contentious, paper states demyelination likely occurs with DAI, and although rare case reports of ADEM post bacteria infection, however other than flipping a coin, I would go with ADEM follws bacterial infection as preferred answer with false (despite neither being mentioned in Robbins). 3. DAI causes demyelination - F - inertia forces - axos stretched, rarely disconnected or "sheared" (except only in most severe injury). Non-disrupted axons undergo traumatic depolarization, metabolic alterations, cellular swelling and cytotoxic oedema. "autoaxotomy". See below 7. Of demyelinating disease, which is false? (TW) 1. ADEM follows a bacterial infection - T - most patients it follow a viral illness, but has been reported after bacterial infection, immunizations, and drug and serum administration. 2. DAI causes demyelination - F - inertia forces - axos stretched, rarely disconnected or "sheared" (except only in most severe injury). Non-disrupted axons undergo traumatic depolarization, metabolic alterations, cellular swelling and cytotoxic oedema. "autoaxotomy". See below 3. MS is perivenular - T - perivenous demyelination, oligodendrocyte destruction. 4. Rasmussen encephalitis is typically unilateral - T - unilateral progressive cortical atrophy

Answer 143

1. Kernohan’s notch in the parietal lobe - F - displacement of brainstem against the contralateral tentorial edge with injury to the brain stem, not parietal lobe. 4. Which is not associated with raised intracranial pressure? (TW) 1. Kernohan’s notch in the parietal lobe - F - displacement of brainstem against the contralateral tentorial edge with injury to the brain stem, not parietal lobe. 2. Duret haemorrhage of the cerebral peduncle - T - brain stem hemorrhage involving midbrain and pons / haemorrhage in lateral brain stem due to massive temporal lobe herniation. 3. Infarct contralateral medial occipital lobe - T - generally there is ispilateral compression of PCA 1st, followed by contralateral side. 4. Early findings of enlarged ipsilateral ambient cistern - T - ipsilateral CPA cisterns also enlarge (Osborn).

Answer 144

2. HSV1 is the commonest cause of herpes meningitis - F - HSV-2 is responsible for most cases of herpetic viral meningitis (Path notes). HSV-1 causes 95% of all herpetic encephalitis. 5. Which is false regarding HSV? (TW) 1. It is grossly necrotising and often haemorrhagic - T - hemorrhagic, necrotizing encephalitis of gray and white matter (primarily limbic system). Severe edema an dmassive tissue necrosis with hemorrhage typical. 2. HSV1 is the commonest cause of herpes meningitis - F - HSV-2 is responsible for most cases of herpetic viral meningitis (Path notes). HSV-1 causes 95% of all herpetic encephalitis. 3. 80 – 90% of children have had HSV 1 infection - F (less correct)- 30% of HSV-1 Abs found in university students. HSV-2 Abs up to 60% of lower socioeconomic groups, and 10-30% (HSV2) higher socioeconomic groups,...... and 3% in nuns were seropositive for HSV2. 4. HSV1 encephalitis most common in adults - T - Occurs at any age. Highest incidence in adolescents and yong adults. Approx 30% or patients are less than 20yo.

Answer 145

4. Pleomorphic xanthoastrocytoma - F - rare distinct astrocytoma subtype tumor of children and young adults. Astrocytic tumor. 6. Which is not a mixed neural/glial tumour? (TW) 1. Ganglioglioma - T - benign tumor composed ofneoplastic astrocytes and ganglion cells. 2. DNET - T - mixed neuronal-glial neoplasm of infancey with a distinct desmoplastic component. 3. Lhermitte Duclos - T - dysplastic gangliocytoma of cerebellum - very rare, tumor-like neuronal lesion of the cerebellum, with distincet dysplastic features. 4. Pleomorphic xanthoastrocytoma - F - rare distinct astrocytoma subtype tumor of children and young adults. Astrocytic tumor. 5. Neurocytoma - T - Interventricular tumor composed of uniform round cells with immunihistochem an ultrastructural features of neuronal differentiation. Arises from septum pellucidum. Neuroglial tumors - nerve cells and glial cells of the brain come from a primitive neuroepithelial precur cell and germinal matrix. Pure neurons = ganglion cells (gangliocytoma, neurocytoma). Tumors of oligodendrocytes and astrocytes may be combined with ganglion cells and called gangliogliomas. If abnormalities which are considered to incorporate all these tumor types - can be called neuroepithelial tumors (DNET).

Answer 146

c. Hypovolaemic shock

Answer 147

c. Lymphocytic hypophysitis

Answer 148

b. Papillary RCC