Skin signs of internal malignancy.

Nonspecific dermatologic problems occasionally associated with malignant disease include pruritus, reactive erythemas and skin infections. Frequently associated with internal neoplasms are acanthosis nigricans, dermatomyositis, rapid development of multiple seborrheic keratoses, hypertrichosis lanuginosa and other syndromes. Skin metastases may be the first signs of internal cancer. The most common visceral primaries are the lung and colon in men and the breast, colon and ovary in women. Recognizing these lesions can lead to early diagnosis and improved prognosis.