Much has been written about what constitutes a paraneoplastic syndrome, but considerable confusion remains. The term paraneoplastic partially derives from the Greek word para, which, among other things, means "by the side of," denoting a closeness of position, a spatial or temporal association. This broad definition is unfortunately not very useful. The term cutaneous paraneoplastic syndrome would best be restricted to those dermatoses that are the direct result of an internal malignant disease, excluding the following: (1) those dermatoses that may be associated with, but that are not caused by, the tumor (ie, genodermatoses such as the mucosal and conjunctival neuromas of patients with multiple endocrine neoplasia type 3 or 2b, which, in turn, is associated with medullary thyroid carcinoma and with pheochromocytoma), in which skin lesions are a marker for the syndrome, not necessarily for the cancer associated with the syndrome; (2) skin alterations caused by a carcinogen