A Case Report of Folliculotropic Mycosis Fungoides: Diagnostic Criteria and Treatment Strategy

Folliculotropic mycosis fungoides (F-MF) is considered a unique variant of mycosis fungoides (MF), which is a form of cutaneous T-cell lymphomas (CTCLs). F-MF can appear in various forms, including patches, papules, plaques, nodules, and tumors. It often affects the face and extremities, with some cases involving the eyebrows. The distinction between F-MF and classical MF can be based on histopathology, which can demonstrate the involvement of hair follicles in the disease process. However, this differentiation can be complex. Immunohistochemical studies can sometimes assist in this distinction by showing differences in cell ratios. We describe a patient with hairless lesions and fine scaling, primarily located on the face, including eyebrow involvement, as well as on the extremities. Through a combination of clinical observations, dermoscopy, histopathology, and immunohistochemical analysis, a potential diagnosis of F-MF was considered. These diagnostic methods allowed us to accurately determine the disease subtype, aiding in both prognostic and therapeutic decisions.