Primary central nervous system lymphoma in homosexual men. Clinical, immunologic, and pathologic features.

Primary central nervous system lymphoma constitutes one of the criteria for the acquired immune deficiency syndrome (AIDS), yet a paucity of information is currently available regarding the clinical, immunologic, or pathologic features of these patients. Six homosexual men presenting with primary central nervous system lymphoma were evaluated. Five of these patients presented with altered mental status. All lymphomas were intracranial. B cell immunoblastic sarcoma was found in five. Immune phenotyping studies performed in five patients revealed monoclonal lambda light chain in three, whereas one expressed only IgG heavy chain, and one demonstrated another B cell (LN-1) surface antigen. Hypodense, contrast-enhancing lesions were apparent on computed axial tomographic scanning of the brain, in sharp contrast to isodense or hyperdense lesions reported in primary central nervous system lymphomas without underlying immunodeficiency. Immunologic abnormalities in these patients were similar to those in AIDS presenting as Kaposi's sarcoma or with opportunistic infections. In spite of therapeutic interventions, survival was short, and only one patient is currently alive.