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