Brain Tumors

Question 1

Most common brain tumor in children?
Where are these located?
Tx?

Answer 1

Pilocytic Astrocytoma

Cerebellum

Tx = Primarily Surgical (good prognosis)

Question 2

Diffuse astrocytoma:
- Location?
- Biologic behavior / prognosis?
Tx?

Answer 2

• Preferential supratentorial location
• Relatively slow-growing (survival 6-8 years) but invariably progresses to higher grade tumor
• Surgical excision; usually followed by radiation and chemotherapy

Question 3

Majority of primary brain tumors in adult are what 2 types?

Answer 3

Anaplastic astrocytoma (III) and glioblastoma (IV) (80%)
(both high grade)

Question 4

Medulloblastoma:

• Age group typically seen in?
• Location?
• Cell(s) of origin?

Answer 4

• Children & young adults
• Cerebellum
• Primitive neuroectodermal cells in roof of 4th ventricle or external granular layer of cerebellum

Question 5

Medulloblastoma:

• Tx?
• Prognosis?

Answer 5

• Surgery, chemotherapy (radiation in older children)

- >50% 5-year survival (range 30-80%); recurrences common

Question 6

Type of tumor?

• Densely cellular small “blue cell” tumor
• High rate of tumor cell proliferation and necrosis
• May show neuronal (common), glial differentiation, or both

Answer 6

Medulloblastoma

Question 7

Meningioma:

- Cell of origin?

Answer 7

• Arachnoid cap (meningothelial) cell (Specialized neural crest-derived cells forming pia-arachnoid coverings of brain and spinal cord and arachnoid granulations — involved in resorption of CSF)

Question 8

Most common non-glial primary CNS tumor in adults?

Answer 8

Meningioma

15% of primary brain tumors in adults

Question 9

Meningioma:

Tx?

Answer 9

• Surgical removal

- Radiation (for inaccessible, difficult to remove or higher grade tumors)

Question 10

Meningioma - does it affect brain by invasion?

Answer 10

No, it compresses on the brain

though they may invade bone & soft tissue

Question 11

Schwannoma:

• Location?
• Tx?

Answer 11

– Cranial & spinal nerve roots
– Most intracranial schwannomas originate from the vestibular branch of CN8 (clinical presentation = unilateral hearing loss)

Tx = Surgical resection or stereotactic radiosurgery

Question 12

Schwannoma - compress or invade brain tissue or both?

Answer 12

Compress, but do NOT invade, brain or SC

Question 13

Diagnosis (type of brain tumor)?
– Benign spindle cells
– Compact (Antoni A) and loose (Antoni B) areas

Answer 13

Schwannoma

Question 14

Most common primary CNS Lymphoma?

Answer 14

Diffuse Large B-cell Lymphomas

Question 15

Most common primary sites of secondary CNS tumors?

Answer 15

– Lung (50-60%)

Then some order of: breast, skin (melanoma), colon, kidney

Question 16

Metastatic tumors that spread to the brain hematogenously, typically spread to what location in the brain?

Answer 16

Grey-white junctions

metastatic lesions to brain most commonly occur via hematogenous spread

Question 17

Most common Sx of brain tumor?

Answer 17

• Headache (50%)
• • (usually dull, constant, like “tension headache”)
• Nausea/vomiting (40%) (due to ↑ICP)
• Seizures (if cortex involved – more common in primary brain tumors)
• Syncope (due to ↑ICP)
• Papilledema (only w/ longstanding ↑ICP)
• Cognitive dysfunction
• Focal weakness, numbness, reflex changes

Question 18

Brain Tumor Dx workup?

Answer 18

Imaging:
- MRI with gadolinium is the best method of initial imaging. If MRI cannot be done, CT with contrast is indicated (better if bone involved)

Biopsy:
An adequate tissue sample is needed for accurate diagnosis of brain tumor. Biopsy may be open or stereotactic.
- Usually done during surgical resection

Question 19

For __a__, maximum surgical excision is usually done , but this does NOT mean complete resection!.

For __b__, stereotactic biopsy only is done since reducing tumor size does not improve outcome.

__c__ are usually completely resected.

Answer 19

a) gliomas
b) CNS lymphoma
c) Meningiomas

Question 20

Gliomas of the ____ do better w/out surgery & are treated based on imaging characteristics.

Answer 20

pons

also goes for these tumors:
• Small tumors in eloquent cortex
• Surgically inaccessible meningiomas
• Patients with one or more new mets and
– known primary cancer which likes to go to the CNS.
– primary tumor that can be found with imaging of chest, abdomen and pelvis, or bone scan. Then primary or another more easily accessible met can be biopsied
– patients with mets and poor functional status and prognosis
Brain Fontneau

Question 21

Why is there a limit to how much radiation a brain can have?

Answer 21

B/c delayed damage to the blood vessels can cause late tumor necrosis or stroke

Also, whole brain radiation also causes cognitive dysfunction, particularly in children.

Question 22

GBM & Anaplastic Astrocytoma:
Chemotherapy standard of care?
(hint: oral alkylating agent)

Answer 22

Temozolamide

Question 23

For what purpose is Bevacizumab used in GBM & Anaplastic Astrocytoma chemotherapy?

Answer 23

It may be used to block blood vessel growth in tumor

Question 24

System management drugs for brain tumors:

- For Edema with increased ICP?

Answer 24

Corticosteroids (also for headaches)

These drugs make the blood brain barrier tighter limiting edema (but also decrease penetration of chemotherapy agents).

Question 25

What type of tumors are most primary spinal cord tumors?

Answer 25

Ependymomas

#2 = Astrocytomas

Question 26

Common Sx of patient w/ primary or metastatic SC tumor?

Answer 26

radicular back pain which is WORSE when sleeping (due to ↑swelling from raised venous pressure when supine)

(in comparison to disc disease where supine posture reduces pain)