Practice vivas

Question 1

Inverted papilloma

Answer 1

Differential - mucocele (complete opacification by mucous, with bony expansion 2 to drainage obstruction)
Antrochoanal polyp - arise in maxillary sinus and expand posterior nasal cavity and nasopharynx
SCC, olfactory neuroblastoma, other tumour

Arise most commonly in lateral wall of nasal cavity, in proximity to the maxillary ostium. Often extends into maxillary sinus as expands.

High association with malignancy (degenerate to SCC 15% and others), and tend to recur

T2 and T1+ convuluted cerebriform pattern.

40-60, male prediliction

HSV 6, 11
May calcify

Question 2

SCC with nodes

Answer 2

Look for subtle SCC primary if see nodes

Question 3

Cervical lymph node groups

Answer 3

1 anterior to submandibular
2 jugular, base of skull to hyoid
3 lower hyoid to cricoid, lateral to medial margin of carotid vessels
4 lower hyoid to clavicle, lateral to carotid, anteromedial to SCM and then scalene
5 posterior triangle
6 pre laryngeal, hyoid to manubrium. Anterior to 3 and 4
7 superior mediastinal, between CCAs, to brachiocephalic level
1a submental b submandibular
5a upper, b lower (cricoid)

Question 4

Fungal sinusitis

Answer 4

Allergic fungal - chronic, associated with asthma, expansion and possibly erosion
Centrally hyperdense material
Acute invasive fungal sinusitis - not hyperdense, tend to be immunocompromised or diabetic
Chronic invasive

Question 5

Parapharyngeal space

Answer 5

Parotid and masticator both displace medially (antero and postero respectively)
Carotid space displaces it anteriorly
Retropharyngeal and pharyngeal mucosal space displace it laterally (antero and postero respectively)

Pleomorphic adenoma deep lobe can appear entirely extra parotid. The tumour can also rarely arise from rests in the parapharyngeal space

Question 6

Parotid gland anatomic pathologies

Answer 6

Deep and superficial lobes, separated by facial nerve (retromandibular vein approximate)
Not truely anatomically discrete - important surgically
Most benign tumours are in superficial lobe (though rarely deep also - e.g. pleomorphic adenoma, which when deep can appear entirely extra parotid, or can arise from rests in the parapharyngeal space) while most malignant involve both
Exclusive deep lobe tumours are rare - use parapharyngeal sapce to help localise

Question 7

Most common malignant parotid gland tumour

Answer 7

Mucoepidermoid carcinoma (these most commonly arise in parotid gland also)
Perineural spread (as with adenoid cystic)

Question 8

Glomus tympanicum paraganglioma

Answer 8

The most common middle ear tumour
2nd most common head and neck paraganglioma after carotid body
Other common: cholesteatoma, schwanomma
Female prediliction, <40
Pulsatile tinnitis, otalgia, or conductive hearing loss
Arise from Jacobsen nerve at Cochlear promintory (tympanic branch of glossopharyngeal)
Soft tissue mass lateral to cochlear promontory. May destroy ossicles

(glomus jugulare, glomus vagale, carotid body)

T1 salt and pepper
Surgical excision, endovascular embolisation pre-op may reduce bleeding risk

Vascular red mass on exam, retrotympanic
Differential aberrant carotid, tympanic membrane haemangioma

Question 9

Middle ear tumour

Answer 9

Glomus tympanicum
Schwanomma facial nerve
Cholesteatoma
Cholesterol granuloma
SCC or BCC or external meatus
Head and neck SCC
Parotid gland masses

Question 10

Petrous apex mass

Answer 10

Mets myeloma
Chondroma, chondrosarc
Meningioma
Schwannoma, cholesterol granuloma, cholesteatoma
Apical petrositis
LCH

Question 11

Clival mass

Answer 11

Mets, myeloma, chondrosarc, chordoma

Or intracranial growing into clivus - pituitary macro (can have dural tail), invasive. Meningioma. Craniopharyngioma

Or Naso/pharyngeal growing up - mucocele, SCC, rhabdomyosarc

Question 12

Papillary thyroid cancer

Answer 12

Mets to nodes c.f. follicular where more rare, but often haematogenous
Follicular cancer and adenoma not differentiated on FNA
Microcalc common
Cavitatory nodes
Medullary tends to have calc in primary and secondary sites (nodes)

Question 13

Intracranial epidermoid

Answer 13

Present due to mass effect
Can have aseptic meningitis
3rd most common CP angle mass after meningioma and schwannoma
May be seen in other cisterns, or in skull
Diffusion restricts
Do not enhance
Differential arachnoid, dermoid (fat on CT, midline)), inflammatory cyst (neurocystercicosis), cystic tumour (solid enhancement)

Question 14

Warthins v Pleomorphic

Answer 14

Warthins can be cystic, most common multifocal mass, and doesn’t calcify
Pleomorphic most common mass, may calcify
Warthins tumour only one which favours males. Benign, can excise or follow up with imaging.
Pleomorphics removed because of risk of malignant degeneration (10% at 15 years)

Question 15

Chordoma

Answer 15

Notochord remants
Sacrococcygeal > spheno-occipital > vertebral
Most common primary malignant sacral tumour
Sacrococcygeal ones are more common in men
Intratumoral calc, moderate to marked enhancement
T2 high, may have haemorrhage
Locally aggressive, recurrence common, poor prognosis. Metastasis uncommon.

Physiliferous cells

Question 16

Chondrosarcoma

Answer 16

Paramidline cf. Chordoma which are midline
High T2 and rings and arcs calc
Meningioma has low T2 and craniopharyngioma (papillary) doesn’t calcify (Cf. chondrosarc and chordoma)

Question 17

Antrochoanal polyp

Answer 17

A type of sinonasal polyp
Inflammatory polyp, lined by respiratory epithelium and with inflammatory infiltrate
Arise from maxillary sinus and pass into nasopharynx, expanding
Young adults, sinus symptoms
Maxillary ostium expanded by mass
High T2, with peripheral enhancement

A sinus retention cyst may be indistinguishable from a polyp

Question 18

JNA

Answer 18

Juvenile nasopharyngeal angiofibroma
Benign but highly vascular
Males almost exclusively
Arise in region of sphenopalatine foramen (posterolateral nasal wall)
Surgery with pre-op embolisation
Prominent T2 flow voids (punctate and serpentine) and enhances
Expanded sphenopalatine foramen with bowed posterior wall of maxillary sinus
Grossly Gray-white tan

Question 19

Basal ganglia calcification

Answer 19

Idiopathic
Fahrs
Toxic - CO, lead, chemo/rad
Infectious - TORCH, TB, AIDS, cystercicosis, toxoplasmosis
Metabolic - hypo, pseudo, pseudopseudohyp, hyperparathyroidism, mitochondrial disease - MELAS

Question 20

Dural AV fistula

Answer 20

Usually idiopathic acquired
Most common documented cause is neovascularity from thrombosed dural venous sinus, typically transverse
Those that have cortical venous drainage have risk of bleeding and of neurological compromise. Those that drain direct to sinuses are benign.

Spinal - hypoperfused spine because of venous congestion, intramedullary oedema - conus often involved as dependent, regardless of location of AVF - AVF is most common spinal vascular malformation

Question 21

Pituitary microadenoma

Answer 21

Dynamic MR delayed enhancement

Question 22

Laryngeal cancer

Answer 22

Subglottic 5%, late detection and poor prognosis (inferior cricoid to true fold). Spares lymphatics.
Glottic 50-60% manifests early with hoarse voice, and tends not to met because of lack of lymphatic drainage. >90% 5yr survivial
Supraglottic 20-30% early lymph node metastases

Smoking, alcohol, HPV, turkish coffee, asbestos

Question 23

Myxopapillary ependymoma

Answer 23

Most common tumour of conus / filum
WHO1
May have CSF dissemination
May haemorrhage, calcify
T2 high and enhance

Question 24

Basal cisterns anatomy

Answer 24

Interpeduncular cistern
Quadrigeminal cistern - between colliculi, splenium, and superior cerebellum
Ambient cistern - laterally surrounds midbrian, connects quadrigeminal to interpeduncular
Cisterna magna
Suprasella
Pre-pontine etc

Question 25

Temporal bone CT anatomy

Answer 25

.

Question 26

Ivory vertebra

Answer 26

``` Blastic met Lymphoma Haemangioma Chordoma Pagets ```

Question 27

Basilar tip thrombus

Answer 27

Also - artery of percheron - single trunk to bilateral medial thalami and rostral midbrain

Question 28

Subependymoma

Answer 28

``` 2/3 infratentorial grade 1, middle, older aged neurocytomas are in younger patients Ependymomas also in younger Small and don't enhance 50% become symptomatic ```

Question 29

Cavernoma

Answer 29

``` Rim of signal loss - haemosiderin Angiographically occult Rarely familial Associated with radiotherapy 20% have a DVA Imaging classification - Zabramski Differential of other multiple bleeding lesions: HTN or amyloid angiopathy Mets DAI Vasculitis ```

Question 30

Throat anatomy on CT

Answer 30

.

Question 31

Odontoma

Answer 31

Tooth hamartoma Complex - calcified but no identifiable tooth components Compound - tooth components Half associated with an unerupted tooth Typically second decade The most common odontogenic tumour of mandible May give rise to a dentigerous cyst "well defined lesion with identifiable tooth components..." or just with calcified components

Question 32

Glomus jugulare

Answer 32

More common than globums vagale Grow into middle ear Cause middle ear symptoms and cranial nerve ones

Question 33

Facet joint synovial cyst

Answer 33

Lumbar spine most common May be a calcified mass Adjacent joint may have OA Can peripherally enhance

Question 34

Dural sinus thrombosis

Answer 34

Higher risk in puerperium than pregnancy Can cause pseudotumour cerebri (intracranial hypertension) Other risks: infection, inflammation, neoplasia (meningioma - mechanical compression), dehydration, thyrotoxicosis, cirrhosis

Question 35

PRES

Answer 35

``` Disordered autoregulation of perfusion HTN and endothelial dysfunction Vasogenic oedema in parietal and occipital lobes Otherwise mainly in watershed areas Infarcts in 10-25%. Haemorrhage 15% ```

Question 36

Cochlear promontory

Answer 36

Bone overlying basal turn of cochlear, protrudes into middle ear. Glomus tymanicum arise here

Question 37

MR intracranial blood products

Answer 37

Hyperacute - isoiso - intracellular oxy Acute - isohypo - intracellular deoxy Early subacute - hyperhypo - intracellular met Late subacute - hyperhyper - extracellular met Chrnoic - lowlow - haemosiderin

Question 38

BLL

Answer 38

Benign lymphoepethlial lesion Mixed solid and cystic lesion of parotids in HIV patient Commonly cervical node enlargement also

Question 39

HIV

Answer 39

PML, HIV encephalitis (/ HIV associated dementia) (and toxoplasmosis, lymphoma) Progressive multifocal leukoencephalopathy Demyelination from JC reactivation Subcortical U fibres commonly involved Asymmetric periventricular and subcortical demyelinating foci - middle cerebellar peduncel and adjacent pons and cerebellum typical Uncommonly diffusion restrict, doesn't enhance Cf HIV which has symmetric T2 abnormality with sparing of subcortical white matter

Question 40

CADASIL

Answer 40

Cerebral AD arteriopathy with subcortical infarcts and leukoencephalopathy Microvasculopathy Confluent white matter T2 hyperintensities

Question 41

White matter disease

Answer 41

Idiopathic/inflammatory/autoimmune eg MS Toxic eg Machiafava bignami, Werneckes, osmotic Vascular - CADASIL, PRESS, microangiopathy, vasculitis Infectious: PML, SSPE (Measles) Post-infectious: ADEM Iatrogenic: Radiation, chemotherapy

Question 42

Gliomatosis cerebri

Answer 42

Growth pattern Most commonly in anaplastic astrocytoma At least 3 lobes Diffuse T1 low and T2 high

Question 43

ADEM

Answer 43

``` Post viral Basal ganglia and spinal cord Can involved gray matter Acute disseminated encephalomyelitis Hurst disease is fulminant haemorrhagic course Sligh male predominance Systemic symptoms Peak 3-5 age ```

Question 44

CJD

Answer 44

``` T2 up in cortex, basal ganglia, thalami Diffusion restricts No significant atrophy, significant rapidly progressive dementia Normal form sCJD, 7 month survival vCJD 16 month - hot cross bun sign Familial 10-15% - 26 month survival ```

Question 45

J-shaped sella

Answer 45

``` Flattening of tuberculum sellae (anterior margin of sella) Normal variant (5%) Optic glioma Hydrocephalus MPS NF Achondroplasia ```

Question 46

Dilated Virchow-Robin spaces, types

Answer 46

Type 1 - basal ganglia (lenticulostriate) Type 2 - entering cortex (perforating medullary) Type 3 - midbrain

Question 47

Dilated VR spaces, causes

Answer 47

``` Normal variant Lacunar infarct Amyloid angiopathy Microangiopathy Infectious - cryptococcus, neurocystercicosis, TB MPS Sarcoid Metachromatic leukodystrophy Sturge-Weber Meningiomatosis ```

Question 48

MELAS

Answer 48

Stroke like episodes in late childhood or early adulthood | MORE HERE

Question 49

Hallevorden-Spatz

Answer 49

Iron deposition in brain Low T2 globi pallidi, with T2* blooming in same areas Dementia

Question 50

Basal ganglia disease

Answer 50

CO - T2 high signal in globi pallidi Methanol tends to affect putamen Mitochondrial disorders affect other parts of basal ganglia) E.g. Leighs AKA SNEM, (predominantly putamina) Wilsons disease has global basal ganglia T2 high CJD also affects basal ganglia, and cortex, with diffusion restriction and T2 high

Question 51

Intraventricular mass

Answer 51

``` Central neurocytoma Choroid plexus Ependymoma Subependymoma SEGA Oligodendroglioma Meningioma - most common trigonal mass Lymphoma ``` Central neurocytoma and oligo may be mistaken both histo and radio

Question 52

Otosclerosis

Answer 52

.

Question 53

Vestibular aqueduct

Answer 53

Normal <1.5mm

Question 54

Thyroid ultrasound, suspicious features

Answer 54

``` Microcalc Extension beyond thyroid Lymph nodes Taller than wide Markedly hypoechoic Ill defined Increased central vascularity ```

Question 55

Thyroid nodule FNA indications

Answer 55

``` >1cm solid with suspicious features >1.5cm solid without suspicious features >1.5cm mixed solid cystic with suspicious features >2cm mixed without suspicious features >50% growth from previous ```

Question 56

Normal pressure hydrocephalus

Answer 56

Callosal angle <90 degrees (perpendicular to the anterior / posterior commisure plane at level of posterior commisure) Evans index >0.3 (Maximum width of frontal horns to internal skull diameter at same level) CSF flow >24.5mL/min (aqueduct)

Question 57

Kimuchi disease

Answer 57

.

Question 58

Kimura disease

Answer 58

.

Question 59

Scerosing sialadenitis

Answer 59

.

Question 60

Dentigerous cyst

Answer 60

Surround crown - unilocular well defined lucency, centred on crown Mandibular 8 > maxillary 8 > maxillary canine > mandibular 5 Associated with MPS and basal cell naevus (KCOT may mimic)

Question 61

Mandibular and maxillary tori

Answer 61

Dense compact bone, often without medulla Benign Inwards from mandible, or in or outwards from maxilla

Question 62

Ameloblastoma

Answer 62

Multicystic, soap-bubble lesion, may erode roots of teeth (and cortex) (KCOT tends to be unilocular, but can mimic) Benign and locally aggressive May be associated with a dentigerous cyst Identical to adamantinomatous craniopharyngioma on histology (used to be called adamantinoma of jaw) 2nd most common ondontogenic tumour (after odontoma)

Question 63

Lytic lesion of jaw

Answer 63

Dentigerous cyst Ameloblastoma (soap bubble, multilocular KCOT (uniclocular) Giant cell reparative granuloma (anterior jaw, honeycomb multilocular. Histo may be identical to ABC according to radpaed) ABC Brown tumour Stafne cyst (pathognomonic appearance, not a true cyst, between molars and angle of jaw) Cherubism (multiple soap-bubble lesions - fibrous dysplasia)

Question 64

Mucocele, paranasal sinus

Answer 64

Expanded obstruced sinus, opacified by mucous Bony margin may be thinned May have peripheral enhancement An polyp and a retention cyst won't completely fill the sinus Tumour such as sinonasal carcinoma and inverted papilloma will enhance

Question 65

Neurocysticercosis

Answer 65

Tapeworm Taenia solium Humans act as definitive host - tapeworms in the intestine after humans ingest larval cysts from undercooked pork meat (pigs are intermediate host) Cysticercosis is extra-intestinal, from faecal oral spread / autoinfection. Ingestion of eggs. Larval form incites an inflammatory reaction which over a period of time undergoes calcification CNS, eyes, skeletal muscle, subcut tissues Rice grain calcification in muscles Subarachnoid (most common, over hemispheres), subcortical (2ndmost after subarach) and ventricular cysts (4th ventricle most common) Parenchymal cysts are small, 1cm, whereas subarach may be 9cm Cyst with dot sign - eccentric scolex (the end of the tapeworm - the scolex may enhance and be hyperintense on T1) Cyst with enhancing rim. Not diffusion retricting. In early phase may not have much enhancement. Seizures Headaches, hydrocephalus Decreased consciousness 4 stages: Vesicular - viable parasite, no reaction Colloid vesicular - cyst with oedema, most symptomatic Granular nodular - cyst starts to retrace Nodular calcified - end stage

Question 66

Calcifying intracranial tumours

Answer 66

``` Craniopharyngioma (rare in papillary variant), meningioma, chondrosarcoma, chordoma Central neurocytoma Ependymoma Subependymoma Ganglioglioma Cavernous haemangioma Dermoid Pineoblastoma / cytoma Pineal germinoma Olfactory neuroblastoma DNET (more microscopic) ATRT Oligodendroglioma ```

Question 67

Ring-enhancing cerebral lesion

Answer 67

``` Abscess Tumour (met of GBM) Demyelination Neurocysticercosis Subacute infarct, haemorrhage, contusion Lymphoma in immunocompromised Radiation necrosis Tuberculoma ```

Question 68

Lymphoma CNS

Answer 68

.

Question 69

Zabramski classification

Answer 69

Of cavernomas 1 - acute haemorrhage - T1 high, T2 low or high 2 - Classic popcorn lesion - peripheral haemosiderin rim, mixed central T1 and T2 3 - chronic haemorrhage - T1 and T2 low centrally 4 - Multiple punctate microhaemorraghes - best seen just on SWI

Question 70

Mixed vascular malformation

Answer 70

Cavernoma + DVA | DVA rarely bleed, but

Question 71

Cavernoma

Answer 71

20% have a DVA Associated with radiotherapy Angiographiccaly occult Can hav familial multiple cavernomas

Question 72

Proptosis, orbital mass

Answer 72

Most common proptosis - thyroid eye disease: usually bilateral symmetric, can cause optic nerve compression and blindness. IMSLO. Tendon usually spared but involved in 8%) Painless: lymphoma, sarcoid, meningioma (lymphoma usually upper outer, separate to muscles, rarely causes blindness. Sarcoid usually lacrimal) Painful: Pseusdotumour (usually muscle, involves tendon) Cellulitis, Wegeners (usually bilateral circumferential), Also orbital mets, rhabdomyo, ocular melanoma, lacrimal gland can have adenoid cystic carcinoma, adenocarcinoma