Abstract: CHEN Si-yuan, YANG Zhen, XIA Ying, QIAN Yue, ZHU Li, WU Yan, LIU Zhi-xiang, TU Ya-ting, WANG Chun-sen, HUANG Chang-zheng. Department of Dermatology, Union Hospital, Tongji Medical College，Huazhong University of Science and Technology, Wuhan 430022，China Corresponding author: HUANG Chang-zheng, Email: hcz0501@126.com 【Abstract】 A 42-year-old man presented with a slowly spreading, asymptomatic, infiltrated erythematous patch in the right side of the chest and back for more than half a month. Dermatologic examination revealed a poorly marginated, pink infiltrated patch sized 5 cm × 7 cm in the right subscapular region of the back and chest. Histopathologically, there was an infiltrate of numerous mononuclear cells in the superficial dermis as well as between collagen fibers in the middle and deep dermis, with epidermotropism of some cells and formation of Pautrier's microabscesses. Mild atypia was observed in some infiltrating mononuclear cells. Immunohistochemistry showed that the mononuclear cells were positive for CD3, CD4 （scattered）, CD5, CD8, CD45Ro, the cytotoxic-granule-associated protein TIA-1, but negative for CD7, CD20, CD30, CD56, CD68, CD79α, and granzyme B, with the percentage of Ki-67-positive cells higher than 20%. T cell receptor （TCR） rearrangement was negative. The final diagnosis was unilesional interstitial mycosis fungoides. 【Key words】 Mycosis fungoides; Case reports ［Publication type］

Key words: Mycosis Fungoides