Folliculotropic Mycosis Fungoides in 20 Korean Cases: Clinical and Histopathologic Features and Response to Ultraviolet A-1 and/or Photodynamic Therapy

BACKGROUND: Folliculotropic mycosis fungoides (FMF) is a variant of mycosis fungoides (MF) that is characterized clinically by variable types of skin eruptions, including plaques, acneiform lesions, and alopecic patches. Histopathologically, FMF is characterized by folliculotropic infiltrates. OBJECTIVE: This study was conducted to scrutinize the clinical and histopathologic features of FMF in Koreans and the responses to phototherapy. METHODS: Twenty Koreans diagnosed with MF who had histopathologic evidence of folliculotropism were enrolled. RESULTS: Eighteen patients had head-and-neck-region infiltration, while five had solitary lesion. In all patients, the atypical lymphocytic infiltrate had a perifollicular distribution. Twelve patients were treated with ultraviolet A (UVA)-1. Eleven of these 12 patients with early-stage FMF experienced >80% improvement (8: complete remission; 3: partial remission). Four patients, including 2 who relapsed after UVA-1, were treated with photodynamic therapy (PDT), reaching complete remission after PDT. CONCLUSION: As FMF has variable clinical presentations, skin biopsy is required to confirm the diagnosis. And both UVA-1 and methyl aminolevulinate-PDT are clinically effective in treatment of early-stage FMF.