Brain tumors of childhood Flashcards
What are the brain tumors of childhood (5)
1) Pilocytic Astrocytoma
2) Craniopharyngioma
3) Choroid Plexus tumors
4) Medulloblastoma
5) Ependymoma
What are the Grade 1 tumors of childhood (3)
1) Pilocytic Astrocytoma
2) Craniopharyngioma
3) Choroid plexus papilloma
What is the Grade 2 tumor of childhood?
Ependymoma
What is the Grade 3 tumor of childhood?
Choroid plexus carcinoma
What is the Grade 4 tumor of childhood?
Medulloblastoma
What is the definition of Grade 1?
Benign, slow growing, normal-looking histology. Long term survival expected. Rare in adults
What is the definition of Grade 2?
Relatively slow growing, some tumor spread, recurs after removal often higher grade. Slightly abnormal histology
What is the definition of Grade 3?
Malignant, tumor spreads, abnormal histology, recurs after removal often higher grade
What is the definition of Grade 4?
Malignant, grows quickly, spreads widely, very abnormal histology, angiogenesis and necrosis present
What is the #1 brain tumor that’s not of neuroepithelial origin? What’s the embryological structure that forms it?
Craniopharyngiomas are formed from Rathke’s pouch (epithelial origin). Most are suprasellar (above the sella turcica) but can have an intrasellar component
Where do pilocytic astrocytomas form?
Centralized location and Periventricular (mostly 3rd ventricle). Also in cerebellum
Pilocytic astrocytomas form in which trisomies?
Trisomy 7 and 8
What is the gross appearance of pilocytic astrocytomas?
Well circumscribed cystic lesion with a mural nodule
What is the histology of pilocytic astrocytoma?
Spindly and elongated astrocytes with Rosenthal fibers
What are Rosenthal fibers?
Thick eosinophilic corkscrew bundles on H&E
What is the marker for pilocytic astrocytoma
GFAP
What is the gross appearance of craniopharyngioma?
Well defined lobulated mass with cyst formation. “Car oil” is present in the cyst
What is the histology of craniopharyngioma?
Stratified squamous epithelium with keratin and CALCIFICATIONS
In which ventricles do choroid plexues tumors grow?
Lateral and fourth ventricles
What genetic syndrome has a propensity to develop choroid plexus tumors?
Li-Fraumeni syndrome (p53 mutation)
What is the histology of choroid plexus adenomas?
Fibrovascular connective tissue fronds (blood vessel within connective tissue) and a single layer of columnar epithelium
What % of choroid plexus tumors are carcinomas instead of papillomas?
1% are carcinomas
What are the markers for choroid plexus tumors?
Epithelial membrane antigen and carotenes
What is a common presenting sign for pts with choroid plexus tumors?
hydrocephalus
What is the #1 solid brain tumor of kids?
Medulloblastoma
When do classic and neuroblastic medulloblastomas occur?
in kids under 10 years old (classic or neuroblastic)
What is the other kind of medulloblastoma? When does it occur?
Desmoplastic. 12-20 years old
Where do classic medulloblastomas grow?
Mid cerebellum (vermis)
Where do desmoplastic medulloblastomas grow?
Lateral cerebellar hemispheres
What is the chromosomal abnormality associated with medulloblastoma?
Isochromosome 17q (both 17q’s from either mom or dad but not both); also can have 1q mutations
What is the gross appearance of medulloblastoma?
Gray nodular mass that is WELL defined
What is the histology of classic medulloblastoma?
Dense undifferentiated cells with little to no cytoplasm (small round blue cells)
What is the histology of neuroblastic medulloblastoma?
More differentiated cells with elongated nuclei and rosettes
What is the histology of desmoplastic medulloblastoma?
Most differentiated cells with germinal centers
What are the markers from medulloblastoma?
Chromogranin, synaptophysin, neurofilaments (remember it’s neural not glial so no GFAP)
What is the prognosis for medulloblastoma?
Good prognosis even though it is Grade 4
What are the two types of ependymomas?
Intratentorial and Spinal
When do infratentorial ependymomas occur?
under 10 years old
When do spinal ependymomas occur?
pt in their 30s
Where do infratentorial ependymomas occur?
4th ventricle near pons
Where do spinal ependymomas occur?
Cauda equina
What is the mutation associated with ependymomas?
22q mutation
What is the gross appearance of ependymomas?
Well demarcated mass with cysts and possible calcifications
What is the histology of ependymomas?
Homogeneous cells with cilia in Pseudorosettes and true rosettes
What is the pseudorosette in ependymoma called?
Perivascular pseudorosette (tumor cells around a central blood vessel)
What are the rosettes called in ependymoma?
True ependymal rosettes - tumor cells around an empty space (little ventricle)
What is a common presenting sign with ependymoma?
Hydrocephalus due to obstruction
What % of ependymomas are supratentorial?
40%
