A case of acanthosis nigricans coexisting with mycosis fungoides.

Acanthosis nigricans maligna (ANM) is a paraneoplastic phenomenon most commonly associated with visceral adenocarcinoma, in particular, gastric adenocarcinoma. Clinically, AMN is characterized by rapidly progressive symmetrical skin thickening and hyperpigmentation of the intertriginous areas with peripheral acrochorda. The diagnosis is made by a detailed medical work-up for occult malignancies with particular emphasis on endocrinological diseases. We report a 67-year-old man that presented clinically with acanthosis nigricans, in which a subsequent diagnosis of mycosis fungoides was made.