[Adult T-cell leukemia--from retrovirus-induced T-cell leukemia in dermatologic patients. Clinical histologic and epidemiologic studies].

In 1976, adult T-cell leukemia (ATL) was reported as a special form of T-cell leukemia. In such cases the following criteria are prominent: strong inclination to leukemic change, incidence of abnormal cells in the peripheral blood, and the existence of an endemic area at the time of the outbreak of the disease. The abnormal tissue infiltrating ATL cells originate from peripheral blood T-lymphocytes, and in these lymphocytes the causal retrovirus HTLV-I could be proven. Since pathognomonic cutaneous manifestations can be observed among almost 50% of the patients, knowledge of this disease is of great importance to dermatologists. Two cases are reported focussing on the clinical and histopathologic findings concerning the cutaneous manifestations. Epidemiologically, up to 1984, we collected and analyzed 153 Japanese cases. There is a minor difference in sex distribution, but the incidence of ATL is highest among people in their fifties. The region of Kyushu, especially the southwestern part, and of Okinawa proved to be the endemic centers of ATL.