Primary central nervous system lymphoma (PCNSL) is a rare and highly aggressive type of non-Hodgkin lymphoma. Nearly 90% of the pathological types are diffuse large B-cell lymphoma (DLBCL), and a very small number are Burkitt tumor and T-cell lymphoma . PCNSL occurs in the brain, spine, cerebrospinal fluid, and eyes. The annual incidence rate in the United States is 7 cases per million . PCNSL occurs in immunosuppressed patients (e.g., those with human immunodeficiency virus [HIV]/acquired immunodeficiency syndrome [AIDS], who have undergone organ transplantation, or who use immunosuppressive agents) as well as in patients with normal immunity.