277 - CNS Cancers

Question 1

What CNS tumor is most likely to present with hearing loss?

What genetic syndrome do we suspect if it is bilateral?

Answer 1

Vestibular schwannoma

• unilateral tumors are sporadic, but bilateral tumors are pathognomonic for NF2
  
  • defect on chr 22 (merlin protein)
• presents w/ gradual hearing loss, tinnitus, and dizziness
• b/c of slow growth reate, vestibular system compensates and dizziness is less present
• CN7 dysfunction may be seen w/ large tumors
• sugery can be curative, low mortality, but high morbidity (hearing loss, facial paralysis)

Question 2

ATRX loss is associated with which CNS tumor?

Answer 2

Astrocytoma

Question 3

What are the histological hallmarks (2) of a meningioma?

Answer 3

Psammoma bodies

Whorled-appearance

Question 4

What is the gold standard for diagnosing CNS malignancy?

Answer 4

MRI w+w/o contrast

Question 5

What is the most common malignant primary brain tumor?

Answer 5

Glioblastoma

• Pseudopalisading necrosis and microvascular proliferation*
• Most common malignancy in the brain = metastases*
• Most common primary brain tumor = meningioma*
• Most common malignant, primary bain tumor = glioblastoma*

Question 6

Which 3 cancers are most likely to metastasize to the brain?

Answer 6

Lung

Breast

Melanoma

Question 7

What is the histological hallmark of oligodendroglioma?

Answer 7

Fried egg cells with chicken-wire vasculature

Question 8

What makes something in the CNS contrast-enhance?

Answer 8

Breakdown of the blood-brain barrier

Question 9

What are the distinguising histologic features of a glioblastoma?

Answer 9

Pseudopalisading necrosis and microvascular proliferation

Question 10

How does MGMT methylation affect glioblastoma prognosis?

Answer 10

MGMT metylated = better prognosis

Question 11

What is the treatment approach to meningioma?

Answer 11

Observe if asymptomatic

Resect if symptomatic

Benign tumors, usually does not cause death

Question 12

What kind of tumor is most likely in this patient?

Answer 12

Meningioma

• Homogenously contrast-enhancing with dural tails*
• Histology will have whorls/psammoma bodies*

Question 13

Which kind of brain tumor stains GFAP+ ?

Answer 13

Astrocytoma

Includes all grades:

• 1: pilocytic astrocytoma
• 2: Diffuse astrocytoma
• 3: Anaplastic
• 4: Glioblastoma multiforme

Question 14

What tumor marker is pathognomonic for oligodendroglioma?

Answer 14

1p19q co-deletion

Question 15

What is the role of corticosteroids in the treatment of primary CNS lymphoma?

Answer 15

Can be helpful, but…

• Must do a biopsy before starting corticosteriods so that it doesn’t affect biopsy results
• Should not be used alone
  
  • If used alone, will recur and be resistant to steroids
  • Use MTX-based chemotherapy / whole brain radiation too

Question 16

1p19q deletion is pathognomic for what CNS tumor?

Answer 16

Oligodendroglioma

Question 17

What is the most common presenting symptom of primary CNS lymphoma?

Answer 17

Behavioral change / cognitive impariment

• Headaches
• Lateralizing signs
• Classic B symptoms are ususally absent

Question 18

Describe the headache characteristics that are concerning for CNS malignancy

Answer 18

• Worst in the morning, disappears after rising
• Gradually increases in frequency, duration, serverity
  
  • -> eventually becomes constant
• Worsens with things that increase ICP

Also nausea, vomiting due to increased ICP

Question 19

What is the cell of origin in glioblastoma multiform?

Answer 19

Astrocyte

Grade 4

Question 20

List 2 risk factors for meningioma

Answer 20

NF-2

Prior ionizing radiation

Question 21

What is the most common primary brain tumor?

Answer 21

Meningioma

Glioblastoma = most common malignant primary brain tumor

Question 22

What mutation is characteristic of lower-grade gliomas?

Answer 22

IDH mutation

Question 23

Answer 23

Seizure

Common presenting symptom of CNS tumor

Question 24

Which CNS malignancy is most likely to present as a single, ring-enhancing mass with surrounding edema?

Answer 24

Primary CNS lymphoma

Question 25

What is the treatment for glioblastoma?

Answer 25

surgery + conventional fractioned external beam radiation therapy + daily temozolomide (chemo)

treatment is noncurative

Question 26

What is the most common malignancy in the brain?

Answer 26

metastasis

Question 27

what is the most common primary brain tumor?

Answer 27

meningiomas

mostly benign, and has a rare malignant variant