Keratoacanthoma (KA) is a growth that is relatively common, benign, and most commonly found in elderly light-skinned individuals. It is more common with individuals having an increased degree of sun exposure and is often found at sites of previous injury or trauma. It is not associated with internal malignancy, except in rare instances where multiple keratoacanthomas are associated with a disease process called Muir-Torre syndrome.

KA is a rapidly growing growth on the skin that expands from 1-2mm to 1-3cm over a few weeks, and develops into a smooth dome-shaped growth with a central keratin core. If untreated, KA's usually stop growing around 6-8 weeks, stay dormant and unchanging for 2-6 weeks, and then finally spontaneously regress slowly over 2 to 12 months frequently healing with scarring. KA's are most commonly found in the hands, arms, trunk and face.