Spiny Hyperkeratosis-Like Follicular Mycosis Fungoides: A Case Report

Folliculotropic mycosis fungoides (FMF) is a rare variant of cutaneous T-cell lymphoma which is categorized as a separate entity. In histopathology, malignant lymphocytes selectively surround and infiltrate hair follicles. FMF has different clinical features in comparison with classic MF which is more refractory to treatment and has a worse prognosis.In the current study, we describe a 42-year-old patient presenting as follicular papules with keratotic spines and alopecia on the scalp, face, and trunk. Histologic examination of the patient’s biopsy revealed follicular and perifollicular T lymphoid cell infiltration without follicular mucinosis. Clonality analysis was interpreted as CD4+ T cell lymphoproliferative disorder. With the final diagnosis of FMF, the patient underwent treatment with oral acitretin and topical corticosteroid and psoralen plus ultraviolet A (PUVA). This case, in addition to the accompanied review of literature, revealed the importance of considering FMF in spiny hyperkeratotic papules in seborrheic areas refractory to antifungal treatments.