Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 3 1 2018 07 24 7 9 EN Maryam Nasimi Department of Dermatology, School of Medicine AND Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. Robabeh Abedini Department of Dermatology, School of Medicine AND Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. Azita Nikou Department of Dermatopathology, School of Medicine AND Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran Elham Alipour Department of Dermatology, School of Medicine AND Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2017 12 30 2018 03 11 Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma, which often appears in the form of patches, plaques, and tumors as originally described by Alibert and Bazin. The manifestation of MF as annular lesions is uncommon, and herein we report one of those cases. A 54-year-old woman complaining of itchy skin lesions from three years before, came to our clinic with no response to topical steroids. In skin examination, there were annular lesions with erythematous slightly raised borders, and some scattered erythematous thin plaques in trunk and extremities with a predilection to lower extremities. Epidermal and poikilodermic changes were not evident. There were no lymphadenopathy and hepatosplenomegaly. Biopsies were obtained from three different lesions and the diagnosis of all samples was consistent with MF. A diagnosis of stage 1B of MF was made and the patient went under oral psoralen and ultraviolet A (PUVA) therapy. MF has different clinical manifestations that can be confused with other inflammatory dermatological disorders. Until now, less than 10 cases of MF with annular lesions have been reported in the English literatures, and most of them initially were under treatment with other differential diagnosis of annular lesion than MF https://crcp.tums.ac.ir/index.php/crcp/article/view/169 https://crcp.tums.ac.ir/index.php/crcp/article/download/169/98