Lec 12: Pathology of Nervous System Tumors

Question 1

Majority of the tumors in children are located

A. supratentorial
B. infratentorial
C. cerebral
D. extraparenchymal
E. intraparenchymal

Answer 1

B.

adult - 70% supratentorial
pedia - 70% infratentorial

Question 2

These are the most common primary CNS tumors.

A. gliomas
B. choroid plexus tumors
C. embryonal tumors
D. metastatic tumors
E. neuromas

Answer 2

A. gliomas

These include

astrocytomas
oligodendrogliomas
ependymomas

Question 3

T/F: Mixed type CNS tumors are usually benign.

Answer 3

T

Question 4

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

Answer 4

E. AOTA

Question 5

Enumerate the four features used in the WHO grading scheme.

Answer 5

A-M-E-N

atypia / nuclear pleomorphism
mitotic activity
endothelial / microvascular proliferation
necrosis

Question 6

ID: Grade IV astrocytomas are also termed as

Answer 6

glioblastomas

Question 7

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

Answer 7

A. IDH1 mutation

Question 8

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

Answer 8

C. 1p19q co-deletion

Question 9

1p19q co-deletion is implicated in the formation of what tumor?

A. primary glioblastoma
B. secondary glioblastoma
C. medulloblastoma
D. meningioma
E. ganglioglioma

Answer 9

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.

Question 10

T/F: The IDH1 mutation is a strong independent favorable prognostic marker in astrocytoma.

Answer 10

T

It allows for diagnostic and therapeutic targeting.

Question 11

ID: This drug introduces methyl groups to DNA of tumor such that it becomes mutated and does not proliferate.

Answer 11

temozolomide

It is an alkylating agent involved in the methylation of DNA.

Question 12

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

Answer 12

B. check for IDH1 mutation

Note: More GFAP is expressed in gliomas than in gliosis.

Question 13

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

Answer 13

D.

p53 mutations are rare in pilocytic astrocytomas.

Question 14

ID: This is the molecular marker for pilocytic astrocytoma.

Answer 14

BRAF fusion gene

Question 15

ID: Rosenthal fibers that aggregate and form clusters are called

Answer 15

eosinophilic granular bodies

Question 16

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

Answer 16

D.

They are LESS fibrillar than astrocytomas.

Question 17

ID: What do you call a grade III oligodendroglioma?

Answer 17

anaplastic oligodendroglioma

Question 18

ID: Perivascular pseudorosettes are characteristic of what tumor?

Answer 18

ependymoma

Ependymal cells line the ventricles and the central canal.

Question 19

This tumor leads to incresed CSF production.

A. medulloblastoma
B. ependymoma
C. choroid plexus papilloma
D. meningioma
E. NOTA

Answer 19

C.

Choroid plexus produces CSF

Question 20

Medulloblastomas are always graded initially as

A. I
B. II
C. III
D. IV
E. WHO grading scheme does not apply.

Answer 20

D. IV

They are high grade tumors with very poor prognosis.

Question 21

ID: Characteristic of medulloblastoma featuring a group of dark blue undifferentiated cells with no cavity nor blood vessel in the center.

Answer 21

Horner-Wright rosettes

Pseudorosettes have blood vessels in the middle.

Question 22

ID: Medulloblastoma-like tumors found supratentorially are termed as

Answer 22

primitive neuroectodermal tumors

Question 23

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

Answer 23

A. wnt MB

Group 3 MB has the worst prognosis.

Question 24

Enumerate two meningioma subtypes that have grade II classification.

Answer 24

clear cell meningioma

chordoid meningioma

Question 25

Enumerate two menigioma subtypes that have grade III classification.

Answer 25

rhabdoid meningioma

papillary meningioma

Question 26

The following are associated with grade II meningiomas EXCEPT

A. >20 mitoses / 10 HPF
B. sheeting architecture
C. hypercellularity
D. brain invasion
E. NOTA

Answer 26

A.

> 20 are associated with grade III already.

4-20 are associated with grade II.

Question 27

ID: Primary CNS lymphoma are typically composed of what cells?

Answer 27

B-cells

Question 28

True of Schwannoma EXCEPT

A. S-100 protein positive
B. arise within the nerve
C. associated with neurofibromatosis type 2
D. may lead to malignant peripheral nerve sheath tumor
E. NOTA

Answer 28

B.

They only arises beside the nerve, only displaces the nerve, and are easily separable from the nerve.

Neurofibromas are the ones that arise within the nerve.

Question 29

Spindle cells in bundles in Schwannomas are characteristic of

A. Antoni A
B. Antoni B
C. Verocay body
D. von Hippel Lindau
E. NOTA

Answer 29

A.

Question 30

ID: What is the most classic manifestation of neurofibromatosis type II?

Answer 30

bilateral vestibulocochlear (CN8) nerve schwannoma