Plasma cell myeloma in patients who are HIV-positive.

This report describes the occurrence of plasma cell neoplasia in three young HIV-positive males. Two patients presented with massive ascites. On cytologic examination of the fluid, many immature plasma cells were noted. Genotyping of fluid demonstrated clonal rearrangement of immunoglobulin heavy and kappa light chain genes in both cases. Postmortem examination on one of these revealed neoplastic plasmacellular infiltrate in various organs, including the bone marrow. The third case presented with a hemorrhagic, rapidly enlarging gingival mass with a histologic appearance of an undifferentiated neoplasm. Immunoperoxidase studies revealed positive staining only for epithelial membrane antigen. On flow cytometry, the neoplastic cells did not mark with leukocyte common antigen or any of the B- or T-cell markers. Cytoplasmic kappa light chain restriction, as well as genotypic studies, confirmed the diagnosis of anaplastic plasmacytoma. In two cases a clonal population was detected using a probe to the terminal repeat region of the Epstein-Barr virus. These results suggest that plasma cell malignancy is another AIDS-associated neoplasm. Its occurrence in this group of patients is not only coincidental.