Acquired epidermal cysts and mycosis fungoides. A possible pitfall in clinical staging.

A 60-year-old man was followed for 5 years for plaque stage mycosis fungoides (MF), follicular mucinosis (FM), and multiple recurrent acquired epidermal cysts on the face, scalp, right axilla, and inguinoscrotal areas. Topical nitrogen mustard and steroids, as well as systemic retinoids controlled the infiltrated lesions of MF, but had no effects on the cysts, which had to be removed surgically. Such cases have to be distinguished from MF in a tumor stage and may suggest that the recurrent cysts represent a paraneoplastic syndrome.