Cutaneous lymphomas in Tokyo: analysis of 62 cases in a dermatology clinic

Background The epidemiology of cutaneous lymphomas revealed that the incidence of lymphomas differed depending on various factors including area, race, and sex, among others. Objective This study was undertaken to analyse the incidence of cutaneous lymphomas in Tokyo. Methods The clinical records and histologic material from 50 patients with lymphomas of the skin and 12 patients with lymphomatoid papulosis seen during the last 10 years at the Department of Dermatology, The Jikei University School of Medicine, Tokyo, have been reviewed. Results T‐cell lymphomas including mycosis fungoides (MF)–Sézary's syndrome (SS) complex and adult T‐cell leukemia/lymphoma (ATL) were more frequent than B‐cell lymphomas. The incidence of ATL is associated with the number of human T‐cell lymphotropic virus type 1 (HTLV‐1) carriers in the general population. Cutaneous B‐cell lymphoma (CBCL) is not as rare as previously thought in Japan. Conclusions Although the frequency of these cases depends on many unrelated factors, these values can provide a rough indication of the incidence of cutaneous lymphomas in Tokyo. The incidence of cutaneous lymphomas may be influenced by changes in environmental factors including viral infections.