Clonal ambiguity of human immunodeficiency virus-associated lymphomas. Similarity to posttransplant lymphomas.

Initial biopsy specimens from two patients with lymphadenopathy and human immunodeficiency virus antibody-positive serum presented considerable difficulty in making specific histologic and immunologic diagnoses, although subsequent biopsy specimens revealed clear progression to acquired immunodeficiency syndrome (AIDS)-associated lymphomas. The initial biopsy specimens revealed multifocal clusters of large blastic lymphoid cells, with some clusters showing a monoclonal lambda light chain predominance, whereas other clusters showed a kappa predominance, indicating considerable phenotypic ambiguity suggestive of polyclonality. This initial clonal ambiguity was followed within two to three months by overt histologic, phenotypic, and clinical malignant transformation to a diffuse high-grade monoclonal B-cell lymphoma. These data have significant implications for the clonality and pathogenesis of AIDS-associated lymphoproliferative disorders. AIDS-related lymphomas may evolve from an initial multiclonal B-cell expansion similar to that described in other severely immunosuppressed patients (eg, with posttransplantation lymphoma).

T-cell prolymphocytic leukemia. Clinical and immunologic characterization.

The clinical course of a patient with extensive skin involvement due to T-cell prolymphocytic leukemia is described. The malignant cells isolated from the patient's blood and skin were studied utilizing cytochemical analysis and multiple monoclonal antibodies directed against cell surface antigens. The leukemic cells displayed a surface antigen phenotype similar to that of normal post thymic suppressor T-cells. On the basis of this study together with the few published reports, it appears that T-prolymphocytic leukemia is derived from lymphocytes demonstrating either the suppressor or helper phenotype, and that extensive dermal infiltration may be independent of phenotypic classification. Although T-prolymphocytic leukemia shares certain morphologic, cytochemical, and immunologic features with chronic lymphocytic leukemia, it is an aggressive disease with an average survival of approximately 6 months and is best thought of as a distinct pathologic entity.