Primary non-Hodgkin's lymphoma of the heart in two patients with the acquired immunodeficiency syndrome.

We report two cases of primary cardiac lymphoma that developed in patients suffering from the acquired immunodeficiency syndrome. Both cases of lymphoma were histologically aggressive as generally observed in patients with the acquired immunodeficiency syndrome. The lymphoma cells in the center of a tumor nodule obtained from one patient were monoclonal B-cells, whereas those at the periphery showed a polyclonal pattern of staining. It is postulated that this represents a monoclonal lymphoma evolving from a polyclonal B-cell lymphoproliferation analogous to those reported in some cases of lymphoma in immunosuppressed patients infected with Epstein-Barr virus. The lymphoma cells in the other case failed to stain for cytoplasmic immunoglobulins. The possible underlying basis for the increase in incidence of lymphoma in immunodeficiency and the reasons for prevalence of extranodal sites are discussed.