Diffuse large B-cell lymphoma involving the central nervous system.

Lymphomas involving the central nervous system are recognized increasingly in immunocompetent as well as immunosuppressed individuals, and the majority of the cases are diffuse large B-cell lymphoma (DLBCL). The aim of this study was to compare the immunophenotype, clinicopathological features, and association with Epstein-Barr virus (EBV) of DLBCL of the central nervous system (CNS) in 3 different clinical situations: primary, in immunocompetent patients; "primary," in immunosuppressed patients; and in patients with secondary involvement by systemic lymphoma. The authors reviewed the clinicopathological features, morphology, immunophenotype (according to germinal-center B-cell-like and nongerminal B-cell-like subtypes), and association with EBV in 36 cases of DLBCL of the CNS, including 25 primary cases, 5 associated with immunosuppression, and 6 cases with secondary involvement. Survival was evaluated in 15 cases of primary CNS lymphomas. Of the 36 patients, 19 were male and 18 female. Only 2 cases of lymphomas were EBV-positive; both occurred in immunosuppressed patients. Separation into germinal-center and non-germinal center subtypes by an immunohistochemistry panel showed that 68% of primary, 80% of secondary, and 83% of the cases associated with immunosuppression were of non-germinal-center subtype, respectively. Patients with non-germinal-center immunophenotype showed significantly worse survival than those with CNS lymphomas of the germinal-center subtype.