Malignant acanthosis nigricans: a review.

Malignant acanthosis nigricans is a dermatosis that appears grossly as a hyperpigmented, velvety, or verrucous hyperplasia of the epidermis, most marked in flexural areas. It is always associated with a malignancy. In 277 cases reviewed, the condition was associated with gastric carcinomas in 55.5%, with other intra-abdominal carcinomas in 17.7%, and with malignancies in other sites in 26.8%. Current theories for the association and pathogenesis of the cutaneous process are discussed.