Diffuse astrocytic and oligodendrogial tumors Flashcards
Diffuse astrocytoma, IDH mutant
ATRX, loss T2/FLAIR hyperintense, expansile, involves both cortex and white matter Vasogenic edema is absent Non enhancing ? Majority of diffuse astrocytomas CDKN2A/B retained -> WHO grade 2 or 3 CDKN2A/B homozygotely deleted or necrosis/MVP -> WHO grade 4 FLAIR-mismatch, age <40, size >6cm
Oligodendroglioma, IDH mutant and 1p/19q codeleted
ATRX retained
T1 hypo
T2/FLAIR hyperintense
expansile, indistinct margins, hetergenenous, involves both cortex and white matter, frontal lobe
Vasogenic edema is absent
SWI - blooming (calcifications)
CE - variable 50% and not prognostic
DWI - normal
Moderatly elevated rCBV
PET - FDG - if as gray matter or MET/FET anaplastic
MRS - moderate Cho, decreased Naa, no lactate (anaplastic have lactate)
Pilocytic astrocytoma
WHO grade 1
BRAF-fusion - MAPK-pathway - good prognosis
Most common pediatric tumor and most common pediatric cerebellar tumor
NF-1 (PA, optic pathway glioma)
expansive - cerbellum (60%)/cerebral hemispheres
- well circumsribed with solid part (T2/FLAIR hyper, T1 hypo, intense CE) and cystic part (+/-wall enhancement, fluid content (follows CSF)). No edema
infiltrative - elongating and widening of the optic nerve, T2 hyper, moderate CE
MRS - high Cho, latate doublets
DWI - high ADC
PWI - low rCBV, first-pass curve
new - high grade astrocytoma with piloid features (IDH wt, CDKN2A/B, ATRX)
Pilomyxoid astrocytoma
WHO grade 2 BRAF V600E (substitution) Young children Hypothalamus/optic chiasm (60%) T2 hyper DWI - high ADC SWI - hemorrhage 20% intese heterogenous CE CSF dissimination is common
Pleomorphic xhantoastrocytoma
WHO grade 2-3 BRAF V600E (substitution) Young adults cortical temporal lobe seizures dural attachement/tail well circumscribed Solid component (iso on CT, T1 and T2, FLAIR hyper) CE homo/heterogeneous marked vasogenic edema 50% cysts associated with cortical dysplasia, ganglioglioma
Ganglioglioma
WHO grade 1 BRAF V600E (substitution) most common glionerual neoplasm, 1% of intracranial tumors glial component affects the biological behavior temporal, frontal lobe shrply/poorly margins, solid/cystic/ cyst with a nodule CT - low density no edema Ca 35% erosion of inner table of scull T2 hyper T1 variable signal CE - variable
Hemangioblastoma
flow voids
peritumoral edema
elevated rCBV (8-10)
vHL
Ependymoma
Anywhere in the CNS, posterior fossa
1-6y (supratentorial 18-24y)
3-5% of intracranial neoplasms
plastic - extends through foramina
Cysts
Calcification
Hemorrhage
DWI - mildly restricted
can seed
RELA - supratentorial, older children, poor prognosis
YAP1 - supratentorial, younger children, good prognosis
Posterior fossa A - young, lateral recess, poor prognosis
Posterior fossa B - older children, midline, good prognosis
Medulloblastoma
DWI
Causes of temporal lobe epilepsy
Mesial temporal sclerosis Ganglioglioma -40% DNET -20% Diffuse low grade astrocytoma -20% Other -20% (pilocytic astrocytoma, pleomorphic xantoastrocytoma, oligodendroglioma)
Neurofibroma
WHO grad 1 NF1 fusiform no cyst/hemorrhage T1 hypo T2 hyper +/- hypo central (target sign) CE - heterogenous mild or no enhancement 3 types: localised intraneural (90%), diffuse cutaneous, plexiform
Schwannoma
WHO grade 1 Antoni A/B growth pattern Local mass effect/nerve dysfunction CN (not olfactory (filia) or optic), vestibulocochlear is most common Round Cysts/hemorrhage/fatty degeneration Displace nerves NF2/schwannomatosis T1 iso/hypo T2 heterogenous SWI - hemosidering in larger tumors CE - strong Subtraction imaging for assessment of growth
Meningioma of pontine angle
Dural base Dural tail Isointense with gray matter Perpendicular to nerves courses Homogeneous enhancement
Multinodular and vacuolating tumor
parietal and temporal seizures juxtacortical cluster of tiny well-defined nodules T2/FLAIR hyper (ddx PVS) no edema no enhancement
Dysembryoblastic neuroepitelial tumor
Supratentorial WHO grade 1 temporal and frontal seizures associated with cortical dysplasia wedge shape, multycystic "bubbly" T2 hyper FLAIR - bright rim sign enhancement 33% no edema remoddeling of adjecent bone ddx: diffuse astrocytoma, oligodendroglioma, pleomorphic xanthoastrocytoma, ganglioglioma)
Gangliocytoma
Supratentorial
very rare
exclusive ganglion cells
Desmoplastic infantile ganglioglioma
Supratentorial Very large tumor in 1st year frontal, parietal both cystic and solid poor prognosis ddx: teratomas, choroid plexus papilloma, AT/RT
Papillary glioneural tumor
Supratentorial
Central neurocytoma
Intraventricular (may be extraventricular) WHO grade 2 Young and middle age adults Third and lateral ventricles, attached to the septum pellucidum Ca 50-70% CT - mixed density T1 iso T2 bubbly FLAIR heterogeneous hydrocephalus is common CE - moderate/heterogenenous
Rosette-forming glioneural tumor of the 4th ventricle
Infratentorial intraventricular
Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos)
Infratentorial parenchymal Cerebellum or vermis WHO grade 1 T2 striate pattern (hyper/iso) Cowdens syndrom (multiple hamartoma syndrome)
Cerebellar liponeurocytoma
Infratentorial parenchymal
Paraganglioma
filum terminale
WHO grade 1
very rare
increased vascularity - feeding vessel
Myxopapillary ependymoma
WHO grade 2 (2021) children and young adults glial cell of filum terminale 83% of primary tumors in that area multiple in 43%
Embryonal tumors with multilayered rosettes
C19MC 95% - amplification (cluster of fetal neural tubes) LIN28A - if present poor prognosis under 2 years poor outcome Cerebral hemispheres 76%, cerebellum, brain stem, pre-sacral space, optic nerve Large heterogeneous (haemorrhage/Ca/cysts/necrosis) may be exophytic No edema DWI - restricted CE - mild/no CT - hyperdense
Atypical teratoid rhabdoid tumor
WHO grade 4
2% of CNS tumors in children 10% under 1 y, can be congenital
INI1 gene - loss of tumor suppression
BRG1 gene
somatic or germ line mutation (rhabdoid tumor predisposition syndrome, kidney, lugns, skin, liver)
if no mutation (CNS embryonal tumor with rhabdoid features)
posterior fossa 52%, supratentoral 39%, pineal, spinal, multifocal
intra/extra axial
marginal cyst, calcification, haemorrhages
DWI - restricted
PWI - increased
MRS - high Cho, lipid peak, no creatin/Naa
rapid growth
CE - may not enhance
DWI to look for metastasis
Medulloblastoma
CT hyperdens
Calcification, haemorrhage, cysts, necrosis
T1
T2
Ce - no/homogeneous/inhomogeneous
DWI - restricted
SHH 25% hemispheric (A), mildine-intraventricular (B), midline-extraventricular/vermis (C)
WHT 11% midline - intraventricular (A), midline-cisternal (B), off-midline-intraforaminal (C), off-midline-intracisterna (D)
Group 3 + 4 65%, midline-intraventricular
MYC - poor prognosis
Desmoplastic medulloblastoma
younger than 3y
Keratocytic odontogenic
primary odontogenic, most common, uni-or multicystic, PTCH, mandible, tooth displacement and tooth resorption, tendency of recurrence, GorlinGoltz syndrome (multiple), DWI
Ameloblastoma
primary odontogenic, second most common, partially solid/multicystic, BRAFV600, unerupted 3rt molar, locally invasive mandible
Odontogenic myxoma
primary odontogenic, multilocular, expansile, well defined borders, honeycomb
Odontoma
primary odontogenic, malformation (hamartoma) compound (tooth) or complex (doesn’t look like tooth)
Osteoma
osteogenic, cortical, fronto-ethmoid, jaws (angle, coronoid process, condyle), Gardners syndrome (multiple)50-60y
Osteoblastoma
osteogenic, >2cm, cortical and cancellous, fronto-ethmoid, orbit or jaw, 20y
Chondroblastoma
chondrogenic, maxilla, mandible or skull base, lytic with areas of calcification
Osteochondroma
pedunculated exophytic bony projection of cortical and cancellous bone, condyle or coronoid process
Giant cell tumor
osteolytic +/-matrix calcification, hemorrhage, mandible, maxilla, ethmoid, sphenoid, temporal bone
Fibrous dysplasia
Fibro-osseous lesions (+ ossifying fibroma, osseous dysplasia)
expansile proliferation of trabecular bone + fibrous tissue, maxilla, mandible, zygoma, spheno-ethmoid, externa cortical bone protrusions, notion of growth by Gd
Ossyfying fibroma
Fibro-osseous lesion (+ fibrous dysplasia osseous dysplasia)
fibrocellular and mineralized, mandible, maxilla, paranasal sinus. Demarcation and encapsulation
Osseous dysplasia
Fibre-Osseous lesions (+ fibrous dysplasia ossifying fibroma)
replacement of bone by fibrous tissue and metaplastic bone, periodontal ligament
Chondrosarcoma
chondrogenic, osteolyticm cortical destruction, calc soft tissue, alveolar maxilla, maxillary sinus, spetum zygomatic bone
Osteosarcoma
osteogenic, lobulated, lytic,-mixed or sclerotic, alveolar maxilla, body mandible
Pleomorphic adenoma
Benign
Adenocystic carcinoma
Malignant
Mucoepidermoid carcinoma
Malignant
Adenocarcinoma
Malignant
Dentigerous cyst (follicular cyst)
Pseudotumor, encloses crown of unerupted tooth, attaches to the cement-enamel junction
Primoderal cyst
Pseudotumor, replace tooth
Residual cyst
Pseudotumor, following tooth extraction
Inflammatory cyst (radicular cyst)
Pseudotumor, result of apical periodontitis, maxilla and mandible
Naso-palatine cyst
Non-odontogenic (fissural) cyst, developmental, foramen incisivum, sometimes unilateral
Naso-alveolar cyst
Non-odontogenic (fissural) cyst, developmental, submucosal anterior to premaxilla, posterior to nasal ala
Simple bone cyst
Non-odontogenic pseudocysts, corticallated scalloped unilocular cyst in mandible, no root resorption, nonexpansile
Stafne cyst
Non-odontogenic pseudocysts, developmental defect anterior to angle of mandible, part of submandibular gland
Perineural spread
most common in cutaneous and mucosal malignances (BCC, SCC), salivary gland malignancies (especially ACC), nasopharyngeal carcinoma, desmoplastic melanoma, lymphoma, leukemia and myeloma
Diffuse astrocytoma, IDH wt
WHO grade 4 Older, multifocal brainstem No cystic changes DWI - restricted CE - variable PWI - difficult MRS - 2HG IDH might be lowered
Diffuse midline glioma
H3.1/3, K27M, H3 27 wt WHO grade 4 5-11y poor prognosis midline - thalamus, pons, spinal cord
Gliomatosis cerebri
Growth pattern,
3 lobes
T2-FLAIR mismatch
Indicative of No CE IDH-m in astrocytomas (not oligodendrogliomas) T2 hyperintense FLAIR hypo with hyperintense rim ddx bright rim sign in DNET
MR-IDH status
T2-FLAIR mismatch - IDHm
DWI - restricted - IDHwt
MRS - 2HG - IDHm
Glioblastoma
most common malignant brain tumor
Intraaxial, gray+white matter, more frequent supratentorial
CE - solid/necrotic/cystic, non spherical
PWI - rCBV >1.75, increased permeability, high CBF
SWI - intratumor suseptibility (necrosis/hemorrhage + vessels)
DWI - variable, often restricted diffusion
non-enhancing tumor - WM, may involve GM, MRS - Cho peak, APT, DWI and PWI may be abnormal
Abscess
DWI - restricted in necrosis
PWI - DSC no angiogenisis
Acute demyelination lesion
Low mass effect incomplete ring look for other lesions DWI - varaible PWI - normal rCBV in enhancing part
Subacute infarct
high T1 in cortex
gyriform enhancement
PWI - normal rCBV in enhancing part
SWI - low cortical signal
PWI - rCBV
High - glioblastoma, high-grade glioma, metastasis, medulloblastoma, capillary telangiectasia
Low - lymphoma, desmoplastic medulloblastomas, pilocytic astrocytoma, vascular, traumatic contusion, inflammation, abscess
Lymphoma
Solid enhancement (rarely necrotic/HIV)
DWI - restricted
PWI - rCBV normal or low, high K2
SWI - normal
Metastasis
Solid or necrotic, spherical
MRS - lipids
PWI - high rCBV
Edema - centered by the lesion, marked T2/FLAIR, no mass effect, facilitated DWI, low PWI, normal MRS
Subependymoma
0.5% of intracranial neoplasms fourth ventricle, lateral ventricle 50-60y WHO grade 1 well circumscribed, cysts are common, can calcification/haemorrhage CE - no or minimal No CSF seeding
Choroid plexus tumors
<5y (2-4% of paediatric brain tumors) trigone of lateral ventricle Papilloma - WHO grade 1 Atypical papilloma - WHO grade 2 Carcinoma - WHO grade 3 Cauliflowerlike lobulated mass, can haemorrhage/calcifications/necrosis Hydrocephalus is common CSF seeding CE - present
Subependymal giant cell tumor
Foramen of Monroe, well marginated, lobulated, heterogenenous (calcifications) 15% of patients with TS WHO grade 1 No CSF seeding CE - strong Hydrocephalus
Intraventricular meningioma
Atrium of lateral ventricle 30-60y Slow growing (large size) Can cyst/calcification CT iso/hyper Local CSF-obstruction
Central neurocytoma
0.5% on intracranial neoplasm Septum pellucidum or lateral wall of lateral ventricle Well circumscribed lobulated mass, bubbly, can haemorrhage/calcifications CT hyper CE - variable 29y Hydrocephalus WHO grade 2
Synaptophysin stain
Rosette-forming Glioneural tumor
Rare WHO grade 1 31.5y Hydrocephalus Fourth ventricle Fairly well circumscribed, heterogeneous solid and cystic
CSF drop metastasis
Ependymoma Choroid plexus tumors Germinoma Medulloblastoma Pineoblastoma Enedymal invasion - GBM
Craniopharyngeoma
craniopharyngeal duct remnant - floor of third - pituitary
10-14y/40-60y
Cystic/solid with variable signal in cysts, can calcification
T1 hyper
CE - solid nodules
Germinoma
child/young adults Pineal and/or hypothalamus T2 hyper CE - homogeneous CT - slight hyper
Meningioma
15-20% of intracranial tumor in adult
Arachnoid cap cells/meningocytes
50% falx, parasagittal, lateral convexity
40% basal, subfrontal, olfactory groove, sphenoid wing and suprasellar
Dural based, CSF cleft, widening of subarachnoid spaces, intervening vessels, dural tail, hyperostosis (reactive hypervascularity)/erosion of calvarium
CT - hyperdense
T1 iso/hypo
T2 iso/hyper
CE - homogeneous, in bone - intraosseous
Edema 60%
Hemorrhage is rare
WHO grade 1, 2 (atypical, papillary, rhabdoid) and 3 (anaplastic - may infiltrate of brain)
Look for vascular encasement, venous infiltration, hypervascularity
Epidermoid
CSF like on CT, T1 and T2
DWI - restricted
Hemangiopericytoma
Younger than meningioma Agressive tumor CE - vivid T2 - flow voids Narrow base of dural attachment Edema in adjacent brain
Primary CNS lymphoma
B-cell 90%
45-70y
immunodeficiency
Parenchymal mass close to surface
T2 hypo
DWI - restricted (EBV hyperintense rim)
Solitary or multiple (50%)
CE - homogeneous, ring (HIV, EBV - 90%), perivascular, ascent
Hemorrhage (HIV, EBV - 70%)
steroid treatment - tumor regression, decrease CE and rCBV and increase ADC
Differentiate from GMB: ADC, rCBV and FDG-PET
Cave - post treatment T1 hyper
Treatment - MATRIx - response DWI, PWI and FDG-PET
Secondary CNS lymphoma
10-15% of NHL
More frequent in relapsing disease
2/3 leptomeningeal, 1/3 parenchymal
CE - leptomeningeal, dural, subependymal, CN
Leukaemia
ALL - children - CNS profylax is standard
AML - adults
Leptomeningeal and CN infiltration
Granulocytic sarcomas (chloromas) - intraparenchymal, CE - strong, DWI - restrict, can be hemorrhagic, dural based, calvarium, orbit, sinuses
Cerebral hemorrhage
Bone marrow infiltration
Neurofibromatosis Type 1
1/3000
Cafe-au-lait, neurofibroma/plexiform neurofibroma, axillary/ingunial freckling, optic nerve glioma (PA, 4-5y), Lisch noduli, sphenoid dysplasia, relative with NF1
Gliomas in NF1 - brainstem (diffuse/focal) medullary, pontine, midbrain
UBO - appear at 3-4y and disappears 10-12y - no mass effect or CE, MRS - preserved Cho/Naa ratio
Gliomas - slow progression, might regress
Moyamoya, arteria ectasia and aneurysm
Plexiform neurofibromas
WHO grade 1
Tortuous, aggressive, infiltrating the nerves
T1 iso to muscle
T2 hyper, inhomogeneous
CE - inhomogeneous
10% malignant peripheral nerve sheath tumor
Spinal neurofibroma
Scoliosis
NF1
Dumbell
Neuroblastoma
Peripheral nerves
7-8% of paediatric tumors
<5y
Neurofibromatosis Type 2
1/25000
Merling
MISME (multiple inherited schwannomas, meningiomas and ependymomas)
Bilateral schwannomas or relative with NF2
Meningiomangiomatosis - rare hamartomatous lesion
Tuberous Sclerosis Complex
1/6000
Hamartin, Tuberin
Cortical tuper (=focal cortical dysplasia), often calcification
WM abnormalities - transmantal sign
Subependymal nodules - lateral wall of lateral ventricle, candle guttering, calcification common, may enhancement
SEGA - foramen of monroe, 2-26%, rapamycin
Sturge-Weber
Facial capillary vascular malformation - trigeminal territory
Leptomeningeal angiomatosis - multiple thin vessels in leptomeninges - enhancement of cortical surface - atrophy and calcifications
Angiomatosis of the choroid of ipsilateral eye
Hypertrophy of choroid plexus
No tumor
Von Hippel-Lindau
Systemic
Hemangioblastoma - highly vascularised nodule that abuts the pial surface cystic component (reactive)
Hemangioblastoma
highly vascularised nodule that abuts the pial surface cystic component (reactive) Cherry on angiography T1 hypo T2 hyper CE - strong, non enhancing cyst wall PWI - high rCBV
Neurocutaneous syndroms
NF1 - PA, neurofibroma NF2 - schwannoma, meningioma, ependymoma Tuberous sclerosis - subependymal giant cell astrocytoma Sturge-Webe syndrome - none Von Hippel Lindau - hemangioblastoma
Spinal Ependymoma
40-50y (NF2 - children) T2 hyper T1 hypo 85% central CE - vivid Well defined borders, neoplastic cysts (tumoral/non tumoral) 30% cap sign
Myxopapillary ependymoma
Conus and cauda WHO grade 1 multilobulated, cystic, haemorrhage CE - always Scalloping of vertebral bodies CFS spread
Spinal Astrocytoma
30-40y (most common intramedullary tumor in children, PA) Fusiform expansion of cord T1 iso/hypo T2 hyper inhomogeneous, illdefined margins CE - heterogeneous, 60-70% May have haemorrhage 30% satellits cysts
Spinal Hemangioblastoma
Benign, rich vascularised (flow void)
2-6% of spinal tumors
If multiple - vHL
small nodule with extensive edema or extensive cyst
Intramedullary metastasis
Edema
T1 iso
T2 hyper
CE - nodular
Intramedullary epidermoid
“cholesteatoma”
1%
slow growing, lumbosacral, dermal sinus in children
congenital or acquired
Melanocytoma
Leptomeningeal melanocytes, intradural extramedullary WHO grade 1 T1 hyper T2 hypo CE - uniform
Spinal Meningioma
Intradural, extramedullary
80% thoracic (posterolateral), 15% cervical (anterior)
50-60y
T2 hyper
T1 iso/hypo
CE - vivid, homogeneous
well circumscribed, delineated from the spinal cord
Spinal nerve sheath tumor
60% intradural extramedullary, 25% extradural, 15% both
cervical or lumbar
schwannoma 65%, neurofibroma, ganglioneuroma (rare)
40y
T1 iso
T2 hyper, sometimes target sign
CE - variable
Spinal neurofibromas
Neurofibromin
NF1
T2 target sign
CE - central or heterogeneous
Spinal schwannomas
= neurinoma Merlin NF2 hemorrhage, cyst CE - diffuse
Paraganglioma
Adrenal (pheocromocytoma), carotid body and gloms jugular Conus, cauda and filum 30-60y WHO grade 1 SDHD - mutation T1 iso T2 hyper inhomogeneous, haemorrhage, intratumoral and adjacent vessels with flow void and strong enhancement
Spinal eosinophilic granuloma
0-10y, vertebral body
Spinal osteoid osteoma
10-20y, posterior elements
Spinal aneurysmatic bone cyst
10-20y, involvement of adjacent levels, posterior elements
Spinal giant cell tumor
20-50y, involvement of adjacent levels, vertebral body, posterior elements
Plasmacytoma
40-60y, involvement of adjacent levels, vertebral body
oval with sharp margins in scull base, clivus and petroclival
Chordoma
40-60y, involvement of adjacent levels, vertebral body
Spinal hemangioma
40-60y, multiple lesions, vertebral body
Multiple myeloma
50-70y, multiple lesions, vertebral body
Spinal metastasis
50-70y, multiple lesions, vertebral body
Spinal lymphoma
Multiple lesions, involvement of adjacent levels, vertebral body
Spinal sarcoma
Involvement of adjacent levels, posterior elements
Spinal metastasis
Arterial seeding, retrograde venous or direct extension
SPECT - osteoblastic
WB-MRI and/or PET
Malignant spinal bone tumors
Lytic without marginal sclerosis
surrounding bone edema
invasion of neighbouring structures
Diagnostic clues: multiplicity, age, imaging characteristics and location
Normal red marrow
<6 moths - low/homogeneous, no enhancemnet
6 months - 45y - intermediate/homogeneous, very limited enhancemnet
>45 y - intermediate/heterogeneous, no enhancement (high SI - more fat, low SI - more cells)
Bone marrow metastasis
Decreased signal =
Spinal hemangioma
T1 high to low T2 high Fat-sat-fluid-sensitive - high CE - yes CT - polka dot
Benign notochord cell tumor
T1 low T2 high Fat-sat-fluid-sensitive - intermediate CE - no Small, sclerotic, hydrated, non-enhancing
Focal red marrow hyperplasia
T1 low T2 low Fat-sat-fluid-sensitive - intermediate CE - subtle signal as cellular red marrow CT - normal/subtle sclerosis
Ethmoid mucocele
Completely opacified and expanded sinus (cell)
Allergic fungal sinusitis
Expanded sinuses with hyper dense stuff
Images /symptoms mismatch
Teenagers
Encephalocele
Ideopathic intracranial hypertension Lateral sphenoid (NOT sternbergs canal)
Persistant craniopharyngeal canal
.
Inferior median clival canal
= canalis basilaris medianas, fossa naviculars
Ecchordosis physaliphora
Remnant of notochord
T1 hypo
T2 hyper
CE - variable
Chordoma
From clivus, osteolytic, hypodense, may be off midline
T2 very high
DWI - very high ADC
CE - variable (minimal)
Chondrosarcoma
Petroclival junction (cartilage)
whirls of calcs 50%
CE - stippled
DWI - very high ADC
Hemangioma of cavernous sinus
T2 very high
DWI - very high ADC
CE - avidly enhancement
Glomus jugulare
Enhancing mass with flow voids
Infiltrative osteolysis
Jugular schwannoma
Smooth bone remodelling
DWI - high ADC
T2 hyper
CE - avid
Endolymphatic sac tumor
T1 hyper T2 hyper Infiltrative, osteolytic Centered at endolymphatic duct CE - heterogeneous
Cholesterol granuloma
Smooth, sharp
Petrous apex expansion
T1 hyper
T2 hyper, hemosiderin rim
Arachnoid granulations
Along sinuses
Lobulated bone remodeling
Not always T2 hyper
Pituitary adenoma
CE - less and more slow than normal pituitary
Ddx - meningioma ehnacenes more than pituitary, reduces artery
Cavernous angioma
CE - centripetal
Rathke cleft cyst
mucoid 25%
intracystic nodules
Head and neck lymphoma
Type 1 - nodal
Type 2 - extranodal (waldeyers ring/outside waldeyers ring)
Type 3 - combined 1+2
Type 4 - multifocal extranodal
nodes 2-10cm
CE - variable (less than reactive)
necrosis
calcifications after treatment
Reactive - multiple, well defined, mild enhancement, ADC >1 (metastasis larger, necrosis, ADC>0.7)
HL - 90% nodal, T2 hyper
NHL - multiple, bilateral solid, CE - moderate (retropharyngeal, occipital, parotid, posterior triangle, submandibular), T2 iso
5% of salivary tumors, parotid 70%
Ocular adnexa >60y most common orbital malignancy
Mucocele
thin rim of the bone
MR signal, CT density variable
Inflammatory pseudotumor
rare, benign
nonspecific imaging - rule out other lesions
Dacroadenitis
OID
gland, orbital and palpebral lobes,
almond shape
Myositis
OID
unilateral thickening of one or two EOM
superior oblique
surrounding fat, tenons and myotendinous junction
ddx: thyroid (I’m slow), cellulitis (CT), CCF (enlarged vein), metastasis (focal mass), lymphoma (focal mass, ADC)
Optic perineuritis
OID optic nerve sheath pain CE - enhancement of sheath and adjacent fat ddx: meningioma, optic neuritis
Optic meningioma
Tram-track
no pain
CT - calcifications
Optic neuritis
spare soft tissue different vision imparement swollen nerve T2 hyper CE - contrast enhancement
Periscleraitis
sclera, uvea and tenons capsule
thickening along the outer rim of the eye, periscleral fluid collection
