precancerous dermatosis

(pree-KAN-seh-rus DER-muh-TOH-sis) A skin disease marked by scaly or thickened patches on the skin, and often caused by prolonged exposure to arsenic. The patches often occur on sun-exposed areas of the skin and in older white men. These patches may become malignant (cancerous). Also called Bowen disease and precancerous dermatitis.