Overview

Question 1

What are the incidence and median age at Dx of PCNSL?

Answer 1

1,000 cases/yr of PCNSL; median age 55 yrs (immunocompetent) vs. 35 yrs (immunocompromised)

Question 2

What % of primary brain tumors are PCNSL?

Answer 2

∼4%

Question 3

What is the sex predilection, and how does it relate to immunocompetency?

Answer 3

Immunocompetent pts: males > females (2:1)

AIDS pts: 95% males

Question 4

What risk factors are often associated with CNS lymphoma?

Answer 4

Immunodeficiency (congenital or acquired) and EBV infection

Question 5

What type of non-NHL is most often associated with PCNSL?

Answer 5

DLBCL is most often associated with PCNSL.

Question 6

What % of PCNSL has ocular involvement?

Answer 6

15% of PCNSL has ocular involvement (vitreous, retina, choroid > optic nerve) that is typically bilat.

Question 7

What is the most common genetic alteration seen in PCNSL?

Answer 7

The most common genetic alteration in PCNSL is the gain of chromosome 12 (12p12–14), which corresponds to the amplification of MDM2 to enhance p53 suppression.

Question 8

If the pt presents with ocular lymphoma, what % later develop CNS involvement?

Answer 8

75% of pts who present with ocular lymphoma develop CNS involvement.

Question 9

With what is orbital lymphoma often associated?

Answer 9

Systemic NHL is often associated with orbital lymphoma.

Question 10

What % of pts present with isolated SC/meningeal involvement?

Answer 10

<5% of pts present with isolated SC/meningeal involvement.

Question 11

What proportion of pts present with CSF involvement?

Answer 11

One-third of pts present with CSF involvement.

Question 12

What % of pts present with PCNSL but have a negative systemic lymphoma workup?

Answer 12

Nearly all pts (>95%) who present with PCNSL have a negative lymphoma workup, so if lymphoma is found outside the CNS, it is NHL with involvement of the CNS.

Question 13

What are the high-risk features of systemic NHL that increase the risk of CNS mets?

Answer 13

Burkitt, lymphoblastic lymphoma, immunocompromised pt, BM+, parameningeal presentation (NPX, PNS), and testicular relapse

Question 14

What % of pts present with multifocal Dz?

Answer 14

Immunocompetent pts: 50%

AIDS pts: 100%

Question 15

What % of pts with grossly unifocal Dz are actually microscopically multifocal?

Answer 15

>90% of pts with grossly unifocal Dz are microscopically multifocal.

Question 16

What % of AIDS pts develop CNS lymphoma?

Answer 16

2%–13% of AIDS pts develop CNS lymphoma. Invariably all are EBV+.

Question 17

What has happened to the incidence of PCNSL over the past 30 yrs?

Answer 17

There has been a dramatic increase (3-fold) in immunocompetent and immunocompromised PCNSL pts.

Question 18

In what regions of the CNS does PCNSL arise?

Answer 18

Brain, SC, leptomeninges, and globe (retina, vitreous)

Question 19

What virus has been associated with PCNSL?

Answer 19

EBV has been associated with PCNSL (60% of immunocompromised cases).

Question 20

Are B cells normally found in the CNS?

Answer 20

No. They develop as part of the pathologic process.

Question 21

What is the more radioresistant NHL: intracranial or extracranial?

Answer 21

Intracranial. Per RTOG 8315, pts rcvd 40 Gy WBRT + 20 Gy boost and 25 of 41 pts (61%) failed in the brain.

Question 22

What % of PCNSLs are supratentorial?

Answer 22

The majority of PCNSLs (75%) are supratentorial.