Background

Question 1

What % of all primary CNS tumors do meningiomas account for in adults?

Answer 1

36%. Meningioma is the most common benign 1st-degree CNS tumor. (Central Brain Tumor Registry of the United States, 2016 update) Autopsy studies suggest prevalence of subclinical meningiomas in up to 3% of the general population.

Question 2

What are the age and sex predilection for meningiomas?

Answer 2

The incidence of meningiomas increases with age (mean age at Dx 62, incidence peaks in the 8th decade). Females are more commonly affected than males (2:1).

Question 3

What are some risk factors for meningiomas?

Answer 3

Prior RT (RR 10, median interval to development 20 yrs), NF-2 (5%–15% risk of multiple meningiomas), and HRT in women (RR 2).

Question 4

Which protein is defective in NF-2, and to what else does NF-2 predispose?

Answer 4

Merlin; bilat acoustic neuromas/ependymomas and juvenile subcapsular cataracts

Question 5

What histologic features can be seen in meningiomas?

Answer 5

Psammoma bodies and calcifications

Question 6

List 5 negative prognostic factors for meningiomas.

Answer 6

Negative prognostic factors for meningiomas:

1. High grade
2. Young age
3. Chromosome alterations
4. Poor PS
5. STR

Question 7

What is the grade classification of meningiomas?

Answer 7

WHO grade I (benign), grade II (atypical), and grade III (anaplastic/malignant)

Question 8

According to the 2007 WHO classification, what criterion upgrades an otherwise grade I meningioma to grade II?

Answer 8

Brain invasion

Question 9

What is the prevalence of grades II–III meningiomas?

Answer 9

6% and 4%, respectively. 90% are grade I.

Question 10

Name the histologies associated with WHO grades II–III meningiomas.

Answer 10

Grade II: atypical, clear cell, chordoid

Grade III: anaplastic, rhabdoid, papillary

Question 11

Of grade I meningiomas, which histologic subtype is most aggressive?

Answer 11

The angioblastic subtype is the most aggressive grade I meningioma.

Question 12

What is the OS difference b/t atypical and anaplastic meningiomas?

Answer 12

Atypical 12 yrs vs. anaplastic 3.3 yrs (Yang SY et al., J Neurol Neurosurg Psychiatry 2008)

Question 13

What are some prognostic factors identified for anaplastic meningiomas?

Answer 13

Brain invasion, adj RT, extent of resection, and p53 overexpression (Yang SY et al., J Neurol Neurosurg Psychiatry 2008)