Nonglial Central Nervous System Tumors

Primary central nervous system lymphoma (PCNSL) is a rare variant of extranodal non-Hodgkin lymphoma that may involve the brain, leptomeninges, eyes, or spinal cord and accounts for up to 5% of all adult primary brain neoplasms. Age-adjusted incidence has increased in the past 3 decades. Infection with HIV and acquired immunodeficiency syndrome increase the risk of PCNSL by 3,600-fold. However, with highly active antiretroviral therapy, the frequency of immune system compromise sufficient for HIV-associated PCNSL (CD4 count ≤50) is dramatically reduced, along with the risk of this disorder.