Clear Cell Acanthoma

Clear cell acanthoma (CCA) was first described by Degos et al in 1962. Also known as Degos acanthoma or pale cell acanthoma, CCA is an uncommon lesion most frequently found on the lower extremities of middle-aged adults and elderly patients. The median age of presentation is 63 years. Clear cell acanthoma has not been shown to have any gender, racial, or ethnic preference. Although lesions typically are solitary, polyploid, multiple, and eruptive forms also have been described, as well as pigmented and giant variants. Clinically, CCA appears as an asymptomatic, red, shiny papule or nodule ranging in size from 5 to 20 mm. The lesion may be covered by a thin crust and surrounded by a collarette of waferlike scale.