Normolipemic Xanthoma Associated With Folliculotropic Mycosis Fungoides

A 60-year-old Japanese man with a 4-year history of multiple yellowish masses and patchy alopecia on the scalp was diagnosed with folliculotropic mycosis fungoides (fMF), a variant of mycosis fungoides, and xanthoma. fMF is characterized by the infiltration of atypical T cells into the follicular epithelium, leading to cyst formation, alopecia, and follicular mucinosis. The patient's condition was complicated by the presence of xanthoma, a rare occurrence in fMF. The study suggests that the tumor microenvironment first triggers histiocyte infiltration around the follicles, and then these histiocytes may phagocytose lipoproteins released from destroyed follicular units, leading to xanthoma formation. The patient's treatment, which included local radiotherapy, narrow-band ultraviolet B, systemic etretinate, and intravenous interferon-gamma, helped reduce the scalp masses, leaving xanthoma.