CNS Tumors

Question 1

Where are the majority of tumors in adults?

Answer 1

Supratentorial

Question 2

Where are the majority of tumors in children?

Answer 2

Posterior fossa tumor

Question 3

How are gliomas classified?

Answer 3

based on resemblance to normal, non-neoplastic glial cells

Question 4

How are gliomas graded?

Answer 4

By the type of glioma

Question 5

What is pilocytic astrocytoma

Answer 5

Most common CNS neoplasm of childhood.
Usually found in cerebellum, optic pathway, hypothalamus, also thalamus, spinal cord, temporal lobe.
WHO Grade 1
Different genetic origins in different anatomical sites
Bipolar neoplastic cells, rosenthal bodies.

Question 6

What is a mutation associated with pilocytic astrocytomas?

Answer 6

BRAF fusion associated with cerebellar tumor

Question 7

What is diffuse astrocytoma?

Answer 7

Predominantly in cerebral hemispheres
Patternless, discoheseive, monotonous cellular infiltrate.
Ki67/MIB1

Question 8

What is anaplastic astrocytoma?

Answer 8

WHO grade 3
Ki67/MIB1 5-15%
Malignant- requires radiation and chemotherapy

Question 9

What is the earliest genetic mutation in diffuse

astrocytomas and oligodendrogliomas of both grades II and III?

Answer 9

Isocitrate dehydrogenase (IDH) - promotes HIF1
Only seen in tumors
Found on immunohistochemistry with antibody to R132H

Question 10

What does IDH1 have to do with prognosis

Answer 10

Without IDH mutation means worse prognosis, likely to progress to high grade glioma

Question 11

What are oligodendrogliomas?

Answer 11

presence of IDH mutation and 1p and 19q codeletions
Does better than diffuse astrocytomas
Sensitive to chemotherapy

Question 12

What are glioblastomas?

Answer 12

Not on IDH pathway.

Question 13

What is Ganglioglioma

Answer 13

Grade 1
Temporal lobe- seizures and temporal lobe epilepsy
Usually

Question 14

What is Ganglioglioma

Answer 14

Grade 1
Temporal lobe- seizures and temporal lobe epilepsy
Usually

Question 15

What is Ganglioglioma

Answer 15

Grade 1
Temporal lobe- seizures and temporal lobe epilepsy
Usually

Question 16

What is medulloblastoma?

Answer 16

Embryonic tumor- only seen in children under age 16

Confined in cerebellum

Question 17

What are the symptoms of medulloblastoma?

Answer 17

Gait, truncal ataxia, lethargy, headache, morning vomiting

Grade 4- responds well to chemotherapy and radiation

Question 18

What are some consequences of medulloblastoma?

Answer 18

can cause hydrocephalus and mass effect

Question 19

What are some consequences of medulloblastoma?

Answer 19

can cause hydrocephalus and mass effect. Can also leave the brain and spreads to the spinal cord (only tumor that metastasizes and is staged)

Question 20

Do brain tumors need to metastasize to become fatal?

Answer 20

This is one of the only types of cancer that does not require metastasis to be fatal.

Question 21

What cancers are most likely to metastasize to the brain?

Answer 21

breast, lung, kidney, melanoma, and GI tract
Melanoma and lung will often show up to the ER with no knowledge of the primary tumor in extremis due to brain metastasis and bleeding into the brain.

Question 22

What is a common gene mutation in patients with pediatric meningiomas or multiple meningiomas?

Answer 22

NF2- Neurofibromatosis