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 identify the range of histopathological patterns and clinical features. The most common histopathologic pattern was folliculocentric/folliculotropic, with or without follicular mucinosis, followed by keratin-filled cysts and comedones. Other findings included keratotic plugging, granuloma formation, and folliculitis. Clinically, grouped follicular papules and patch/plaque lesions were prevalent, along with folliculocentric lesions like milia and alopecia. A significant CD4:CD8 ratio imbalance was noted, and 15.8% of patients developed large-cell lymphoma. The study emphasized the importance of recognizing FMF's diverse presentations to avoid diagnostic errors.