COMPOSITE CUTANEOUS T-CELL LYMPHOMA AND SMALL B-CELL LYMPHOCYTIC LYMPHOMA - MORPHOLOGIC, IMMUNOLOGICAL, AND MOLECULAR-GENETIC DOCUMENTATIONOF CONCURRENT LYMPH-NODE INVOLVEMENT

Synchronous cutaneous T-cell lymphoma and low-grade B-cell lymphoproli ferative disorders have rarely been reported in the same patient. Coex pression of each phenotype in the same lymph node has not, to our know ledge, been previously documented. We describe an 86-year-old man with chronic pruritus and erythroderma and recent-onset peripheral lymphad enopathy and lymphocytosis. Lymph node biopsy provided morphological a nd immunohistochemical evidence of concurrent small B lymphocytic lymp homa and small pleomorphic T-cell lymphoma. Immunophenotyping of nodal lymphocytes demonstrated two distinct clones: IgM-k B-cells with CD5 positivity and CD7 negative T-helper cells. Both immunoglobulin (heavy and light chains) and T-cell receptor (beta I and beta II) gene rearr angements were detected by Southern blot analysis of the lymph node. I n contrast, the immunophenotype of lymphocytes from peripheral blood a nd bone marrow was exclusively that of T-helper cells with atypical CD 7 deletion. Electron microscopic examination of circulating lymphocyte s revealed small cerebriform Sezary cells. This case demonstrates that small lymphocytic lymphoma may coexist intranodally with cutaneous T- cell lymphoma as a unique form of composite T-and B-cell lymphoma.