This article concentrates on the major signs and syndromes that are associated with internal malignancies in the geriatric population. Included are cutaneous metastases, ectopic adrenocorticotropic hormone-producing syndromes, and disorders arising from APUD cell tumors. The major paraneoplastic disorders of dermatomyositis, generalized pruritus, Bazex's syndrome, and acanthosis nigricans also are discussed. Also included are Bowen's disease of skin; arsenical toxicity; and the Peutz-Jeghers', Gardner's, and Torre's syndromes, which are indicative of systemic or organ-related carcinogens.