Cutaneous type of adult T cell leukemia/lymphoma in a French West Indian woman. Clonal rearrangement of T-cell receptor beta and gamma genes and monoclonal integration of HTLV-I proviral DNA in the skin infiltrate.

A 45-year-old woman, a native of the French West Indies who had lived in France since 1973, developed multiple cutaneous plaques and nodules in 1987. Histopathologic studies revealed dermal infiltration with mature activated T cells (CD4+, CD25+, DR+) with nuclear convolutions and epidermatotropisim. High titers of specific human T lymphotropic virus (HTLV)-I antibodies were detected in the serum. Molecular analysis of DNA extracted from the skin tumor biopsy specimen showed a clonal integration of an HTLV-I provirus and a T-cell clonal population as demonstrated by T-cell receptor beta and gamma gene rearrangement studies. Neither HTLV-I provirus nor T-cell receptor rearrangements were detected in peripheral blood mononuclear cells DNA despite the presence of rare adult T cell leukemia cells (less than 1%) and a small excess of DR-expressing cells, and detection of HTLV-I Pol and Px sequences by in vitro gene amplification. In this case only gene analysis of the skin lesions made possible an early diagnosis of a cutaneous adult T cell leukemia. This illustrates the need for such molecular studies to differentiate, in HTLV-I seropositive patients from endemic areas, a HTLV-I-induced T cell lymphoma from HTLV-I-nonrelated cutaneous T cell lymphomas.