Adult Brain Tumors

Question 1

List a few genes and their chromosome aberrations that are risk factors for certain (name them) brain tumors.

Answer 1

Li-Fraumeni Ch. 17- p53- glioma, medulloblastoma

Tuberous Sclerosis Ch. 9/16 - TSC1/2- Subependymal Giant Cell Astrocytoma, Cortical tubers, Glioma

NF1 Ch. 17- Glioma (optic nerve), astrocytoma, glioblastoma

NF2 Ch. 22- Meningioma, schwannoma, ependymoma

MEN Type 1 Ch. 11- Menin- Pituitary

Retinoblastoma Ch. 13- RB1- Retinoblastoma

Von Hippel Lindau Ch. 13- VHL- Hemangioblastoma

Question 2

What are the most common adult brain tumor types?

Answer 2

Astrocytoma > GBM»> others

Question 3

Describe the relationship of ICP to cerebral perfusion pressure and their relationship to ischemia.

Answer 3

^ ICP = v CPP = ischemic symptoms

Question 4

What is the gold standard for Dx of a brain tumor?

How do you get your definitive Dx?

Answer 4

MRI- best for distinguishing tumor from other lesions.
CT- superior for IDing calcifications
DDx- biopsy, except in primary CNS lymphoma (check CSF)

Question 5

Describe the symptoms you would expect with the following herniation:
Cingulate (downward) herniation

Answer 5

Compression of ACA—> contralateral paresis/paresthesia of legs

Question 6

Describe the symptoms you would expect with the following herniation:
Diencephalic (downward) herniation

Answer 6

Compression of brainstem–> drowsiness due to compression of reticular formation—> coma, death
Horner’s sign- compression of sympathetic fibers around ICA

Question 7

Describe the symptoms you would expect with the following herniation:
Uncal herniation (downward through tentorium)

Answer 7

Ipsilateral CNIII palsy

Contra/ipsilateral hemiparesis- compression of posterior internal capsule (?)

Question 8

Describe the symptoms you would expect with the following herniation:
Upward herniation of cerebellum through tentorium

Answer 8

Ipsilateral CNIII palsy
Horner’s syndrome- compression of sympathetic fibers around ICA
Contralateral hemiparesis- compression of posterior internal capsule

Question 9

Describe the symptoms you would expect with the following herniation:
Cerebellar tonsilar herniation (down towards brain stem)

Answer 9

BP/respiratory insufficiency, weakness, Horner’s syndrome (compression of descending sympathetic fibers in hypothalamospinal tract?- 1st order neuron lesion)

Question 10

Pt’s got a glioma (astrocytoma, ependymoma, oligodendroglioma). They are old. What is it?
Where is it?

Answer 10

Glioblastoma Multiforme (grade 4 astrocytoma)
Cerebral hemisphere

Question 11

Pt’s got a glioma (astrocytoma, ependymoma, oligodendroglioma). They are young. What is it?
Where is it?

Answer 11

Juvenile pilocystic astrocytoma (grade 1)

Cerebral hemispheres

Question 12

Pt’s got a glioma. What chemo are you going to give?

Answer 12

Temozolomide + bevacizumab

Question 13

Why are you going to give a pt w/ a brain tumor steroids?

Answer 13

Restore BBB. Reduce inflammation. Temp. relief of symptoms (not a long term solution)

Question 14

Why do you give brain tumor pts NON-ENZYME INDUCING anticonvulsants?

Answer 14

Enzyme-inducing AEDs reduce the efficacy of chemo agents as well as contribute to the development of a number of comorbidities, including osteoporosis, sexual dysfunction, and vascular disease.

Question 15

What functional differences would you expect to see between a micro (

Answer 15

Micro = hypersecretion
Macro = mass effect = hyposecretion + compression of other structures (optic chiasm)---> superior field bitemporal (upper outer quad) hemianopsia due to upwards compression (whereas craniopharyngioma ---> inferior field bitemporal (lower outer quad) hemianopsia due to downward compression)

Question 16

How do we tx pituitary adenomas?

Answer 16

Resection
Octreotide for GH secreting tumors
Bromocriptine/Pergolide for PL secreting tumors

Question 17

Primary CNS lymphoma is a clonal proliferation of what types of lymphocytes?
What are some RFs for PCNSL

Answer 17

B cells

EBV in immunocompromised pts

Question 18

What is the MC CNS tumor in AIDS pts?

Answer 18

primary CNS lymphoma

Question 19

Where are the most common places to find primary CNS lymphoma?

Answer 19

Leptomeninges (Subarachnoid space) and periventricular parenchyma

Question 20

How do we tx primary CNS lymphoma?

Answer 20

It is a VERY resistant cancer
Tx w MTX, as it crosses the BBB
Steroids
Prog. is still 3-4 yrs for young, otherwise healthy pts

Question 21

Meningiomas are derived from this type of cell:
Are these tumors considered axial or extra-axial?
Are they usually malignant?
Histology?
Tx?

Answer 21

arachnoid “cap cells” from arachnoid villi
Extra axial bc outside of brain
Usually benign
Look for psammoma bodies on histo (dural tail calcifications on CT)
Observe, resect, radiation

Question 22

Bilateral acoustic neuromas are associated with what genetic aberration?
How will it present?

Answer 22

NF2 (Ch. 22) inactivating mutation

Hearing loss, tinitis, dizziness, ataxia

Question 23

List the metastatic cancers to the brain by prevalence.

Answer 23

Lung (50%)
Breast
Melanoma
Colon
Renal

Question 24

How will secondary mets to brain look on CT. Is this specific for mets?

Answer 24

Ring enhancing lesion on T1 MRI. Not specific for mets. Could also be abscess, CVA, high grade glioma, lymphoma, demyelination

Question 25

What is the prog. for brain mets?

Answer 25

Untreated: 1 mo
Steroids to mitigate symptoms: 2mo
Throw kitchen sink: 1 yr (steroids + whole brain radiation + chemo +/- resection)

Question 26

Etiology of extradural tumors of spinal cord:

Answer 26

Mets from lungs, breast, prostate

Question 27

Etiology of intradural, extramedullary tumors of spinal cord:

Answer 27

Schwannomas, neurofibromas, meningiomas

Question 28

Etiology of intradural, intramedullary tumors of spinal

Answer 28

Astrocytoma (Peds)
Ependymoma (Adults)
Hemangioblastoma (VHL)

Question 29

How do spinal cord tumors usually first present?

Answer 29

PAIN

Question 30

How do you differentiate a spinal cord tumor from an infected abscess on MRI?

Answer 30

Tumors invade bone, Abscesses do not

Abscesses invade intervertebral discs, tumors do not