Central nervous system lymphoma in the acquired immunodeficiency syndrome
Morgello, S.; Petito, C.K.; Mouradian, J.A.
Clinical Neuropathology 9(4): 205-215
1990
ISSN/ISBN: 0722-5091 PMID: 2171824 Document Number: 355757
Primary central nervous system (CNS) lymphomas were studied in fifteen autopsied patients with the acquired immunodeficiency syndrome (AIDS). Using the working formulation of non-Hodgkin's lymyphomas, the tumors were classified as large cell (7 patients), mixed large and small cell (6 patients), small cleaved cell (1 patient), and unclassifiable (1 patient). The mixed lymphomas displayed unusual features characterized by a high mitotic rate and the presence of numerous medium-sized cells (5 to 10 .mu.), not classifiable using the working formulation. Focal T cell and lymphoplasmacytoid B cell infiltrates accompanied lymphoma cells at the peirphery of and remote from solid tumor masses in 9 cases. Immunohistochemical analysis of the lymphomas suggested B cell neoplasms. All of these patients had concurrent CNS and systemic cytomegalovirus (CMV) infections. The CNS infections were of both viral (CMV, human immunodeficiency virus (HIV), varicella zoster virus (VZV), progressive multifocal leukoencephalopathy (PML) and non-viral (toxoplasmosis, candidiasis) etiology. In the general AIDS population at our institution, the autopsy incidence of CNS infections and systemic CMV was 63% and 60%, respectively. In contrast, the incidence for both these entities was 0% in otherwise healthy, non-AIDS patients with primary CNS lymphoma. These differences were significant by statistical (Chi-square) analysis. The increased incidence of systemic and CNS infections in AIDS patients with CNS lymphoma supports the hypothesis that viral infection plays a role in the pathogenesis of CNS lymphoma in the immunocompromised. Polyclonal lymphoplasmacytoid B and T cell infiltrates accompanying lymphoma may produce diagnostic difficulties on surgical biopsy. As these infiltrates were a frequent feature in this study, we caution that their recognition does not argue against the presence of CNS lymphoma.