Cowden's disease with associated malignant melanoma.

Cowden's disease (multiple hamartoma syndrome), a rare genodermatosis, is inherited in an autosomal-dominant genetic pattern. It is characterized by mesodermal and epithelial hamartomas appearing as verrucous papules occurring predominantly over the central portion of the face, with perioral and acral papular lesions and papillomatosis of the lips, gingiva, and tongue extending through the entire length of the gastrointestinal tract. These skin lesions have been found to be associated with a number of benign and malignant tumors involving the breast, thyroid, skin, ovaries, adipose tissue, and gastrointestinal tract. The authors report the second case of Cowden's disease associated with malignant melanoma and emphasize the need for a high index of suspicion for related benign or malignant tumors in these cases.