The KA is a unique epidermal tumor characterized by rapid, abundant growth and a spontaneous resolution, with the classic presentation in middle-aged, light-skinned individuals in hair-bearing, sun-exposed areas. In the late 1940s, Freudenthal of Wroclaw coined the term keratoacanthoma, owing to the considerable acanthosis observed in the tumor. Controversies have arisen since the 1950s about the real nature of the tumor; some KAs may metastasize, and there is debate over the relationship to SCC.1,2 Many dermatopathologists now classify this tumor as a subtype of SCC.