2024 Volume 39 Issue 2 Pages 186-191
A 75－year－old female from Shimane Prefecture presented with a month－long history of multiple pruritic erythematous lesions on the forearm. She reported no improvement with topical steroids and was referred to our department. Physical examination revealed annular erythematous plaques with an elevated peripheral rim on the trunk and extremities, and granuloma annulare was suspected. Histological findings from the erythematous plaques demonstrated Pautrier’s microabscesses in the epidermis and a nodular infiltrate of lymphocyte－like mononuclear cells and histiocytes in the dermis. The infiltrating atypical cells were CD3+, CD4+, CD7−, CD25+, and CCR+. In the central fading area of the erythema, histiocytes were observed around degenerated collagen fibers. Laboratory examination revealed leukocytosis (11.180/μL) with 11.3% of the abnormal lymphocytes. Serum assay results were positive for anti－HTLV－1 antibodies. The patient was diagnosed with adult T－cell leukemia－lymphoma. One month after the initial diagnosis, the number of abnormal lymphocytes increased rapidly ; however, the patient achieved a complete response after two cycles of CHOP therapy, four cycles of a combination of CHOP therapy and mogamulizumab, and four cycles of mogamulizumab alone.[Skin Cancer (Japan) 2024 ; 39 : 186－191]
