A keratoancanthoma occurs when cells in a hair follicle do not grow normally. The growth apparently is triggered by a minor skin injury in an area that previously had suffered sun damage. Ultraviolet radiation from sun exposure is the biggest risk factor in keratoacanthomas. A keratoacanthoma usually will appear on sun-damaged skin as a thick growth that has a central crusted plug. Keratoacanthomas are rapidly growing, red, dome-shaped bumps with central craters. Some keratoacanthomas can grow to extremely large sizes, occasionally 1 to 3 inches in diameter. Keratoacanthomas appear most often in people who are over the age of 60 and they are considered a low-grade skin cancer.
Keratoacanthomas can be removed by Cryotherapy (freezing the growth with liquid nitrogen), Curettage (scraping and burning off the growth), Surgical removal.