A benign, non-neoplastic, usually self-limiting epithelial lesion closely resembling squamous cell carcinoma clinically and histopathologically. It occurs in solitary, multiple, and eruptive forms. The solitary and multiple forms occur on sunlight exposed areas and are identical histologically; they affect primarily white males. The eruptive form usually involves both sexes and appears as a generalized papular eruption. [MeSH]
