Lec 12: Pathology of Nervous System Tumors Flashcards
Majority of the tumors in children are located
A. supratentorial B. infratentorial C. cerebral D. extraparenchymal E. intraparenchymal
B.
adult - 70% supratentorial
pedia - 70% infratentorial
These are the most common primary CNS tumors.
A. gliomas B. choroid plexus tumors C. embryonal tumors D. metastatic tumors E. neuromas
A. gliomas
These include
astrocytomas
oligodendrogliomas
ependymomas
T/F: Mixed type CNS tumors are usually benign.
T
True of the WHO grading scheme for nervous system tumors
A. predicts biologic behavior B. most applicable to astrocytomas C. grade 2 is infiltrative D. A & B only E. AOTA
E. AOTA
Enumerate the four features used in the WHO grading scheme.
A-M-E-N
atypia / nuclear pleomorphism
mitotic activity
endothelial / microvascular proliferation
necrosis
ID: Grade IV astrocytomas are also termed as
glioblastomas
This is the first mutation in the astrocytoma / oligodendroglioma tumor lineage.
A. IDH1 mutation B. p53 mutation C. 1p19q co-deletion D. EGFR amplification E. MGMT mutation
A. IDH1 mutation
This mutation drives the glioma tumor to progress into the oligodendroglioma lineage.
A. IDH1 mutation B. p53 mutation C. 1p19q co-deletion D. EGFR amplification E. MGMT mutation
C. 1p19q co-deletion
1p19q co-deletion is implicated in the formation of what tumor?
A. primary glioblastoma B. secondary glioblastoma C. medulloblastoma D. meningioma E. ganglioglioma
A.
Primary glioblastomas skip the glioma lineage, meaning the initial presentiation is already glioblastoma (grade IV).
Secondary glioblastomas run through the glioma - astrocytoma / oligodendroglioma - glioblastoma lineage.
T/F: The IDH1 mutation is a strong independent favorable prognostic marker in astrocytoma.
T
It allows for diagnostic and therapeutic targeting.
ID: This drug introduces methyl groups to DNA of tumor such that it becomes mutated and does not proliferate.
temozolomide
It is an alkylating agent involved in the methylation of DNA.
How do you specifically differentiate gliomas from reactive gliosis?
A. stain with GFAP B. check for IDH1 C. stain with india ink D. A & B only E. AOTA
B. check for IDH1 mutation
Note: More GFAP is expressed in gliomas than in gliosis.
True of pilocytic astrocytomas EXCEPT
A. common in children and young adults B. grade I in the WHO scheme C. has Rosenthal fibers D. p53 mutation is common E. NOTA
D.
p53 mutations are rare in pilocytic astrocytomas.
ID: This is the molecular marker for pilocytic astrocytoma.
BRAF fusion gene
ID: Rosenthal fibers that aggregate and form clusters are called
eosinophilic granular bodies
Morphological characteristics of oligodendroglial tumors
A. fried egg appearance B. chicken wire anastomosing capillaries C. more fibrillar than astrocytomas D. A & B only E. AOTA
D.
They are LESS fibrillar than astrocytomas.
ID: What do you call a grade III oligodendroglioma?
anaplastic oligodendroglioma
ID: Perivascular pseudorosettes are characteristic of what tumor?
ependymoma
Ependymal cells line the ventricles and the central canal.
This tumor leads to incresed CSF production.
A. medulloblastoma B. ependymoma C. choroid plexus papilloma D. meningioma E. NOTA
C.
Choroid plexus produces CSF
Medulloblastomas are always graded initially as
A. I B. II C. III D. IV E. WHO grading scheme does not apply.
D. IV
They are high grade tumors with very poor prognosis.
ID: Characteristic of medulloblastoma featuring a group of dark blue undifferentiated cells with no cavity nor blood vessel in the center.
Horner-Wright rosettes
Pseudorosettes have blood vessels in the middle.
ID: Medulloblastoma-like tumors found supratentorially are termed as
primitive neuroectodermal tumors
This molecular subgroup of medulloblastoma has the best prognosis.
A. wnt MB B. shh MB C. group 3 MB D. group 4 MB E. B & C only
A. wnt MB
Group 3 MB has the worst prognosis.
Enumerate two meningioma subtypes that have grade II classification.
clear cell meningioma
chordoid meningioma
