The Clinical Features and Histopathologic Patterns of Folliculotropic Mycosis Fungoides in a Series of 38 Cases

This study examined 86 biopsies from 38 patients with folliculotropic mycosis fungoides (FMF) to describe the range of histopathological patterns and clinical features. The most common histopathologic pattern observed was folliculocentric/folliculotropic, with or without follicular mucinosis. Other patterns included keratin-filled cysts, comedones, and various forms of folliculitis. Clinically, grouped follicular papules and patch/plaque lesions were frequent, along with folliculocentric lesions such as milia, cysts, and alopecia. A significant finding was that 15.8% of patients experienced transformation to large-cell lymphoma. The study emphasized the importance of recognizing the diverse presentations of FMF to avoid diagnostic errors.