Progress in adult T cell leukemia research.

The clustering incidence of adult T cell leukemia (ATL) is found in adult populations who were born in southwest Japan and showed impairment of cell-mediated immunity; all patients with ATL contain antibody for specific ATL associated antigen in their sera. This ATLA positive T cell leukemia is morphologically characterized by leukemic cells in various sizes showing unique nuclear polymorphism. The neoplastic cells bear common immunocytologic markers with inducer T cell subset among the peripheral T2 cell group and functionally show the suppressor inducer activity. Histologic features of lymph nodes were classified to diffuse lymphoma, pleomorphic type in many cases of ATL. The prognosis of patients with ATL is the worst among lymphoid malignancies and almost all patients died within a year accompanied by pulmonary lesions or other infectious inflammatory lesions.