CNS involvement in the non-Hodgkin's lymphomas.

Instances of central nervous system (CNS) lymphomatous involvement occurring amongst 592 cases of non-Hodgkin's lymphoma (NHL) seen between 1967 and 1977 were reviewed. Lymphomatous complications of the CNS were found in 52 patients (9%): 24 with meningeal lymphoma, 20 with epidural compression and 8 with intracerebral lymphoma. Intracerebral lymphoma presented clinically as large parenchymal deposits of tumor unrelated to leptomeningeal disease. Ninety-eight percent (50/52) of all patients had a diffuse histologic subtype and 82% (42/52) had either histiocytic or diffuse, poorly differentiated lymphocytic lymphoma. Bone marrow involvement was an additional determinant of risk and aided in the selection of patients for possible CNS prophylaxis. Either meningeal or intracerebral lymphoma developed in 35% (6/17) of patients with diffuse histiocytic lymphoma and positive bone marrow biopsies. This subgroup was particularly felt to warrant CNS prophylaxis. Further diagnostic and therapeutic management regarding CNS involvement in NHL is discussed.