Keratoacanthoma is a keratinizing, squamous neoplasm characterized by rapid growth and spontaneous involution occurring most commonly on the sun-exposed skin of elderly white persons.1-4 Postulated causes of this tumor include ultraviolet energy, ionizing radiation, chemical carcinogens, trauma, viral infection, and genetic and immunologic factors.1,2 Lichen planus is an inflammatory papulosquamous disorder of unknown cause in which immunologic abnormalities, drugs, or viral infection have been thought to play a role.4 We recently treated a patient who had keratoacanthomas arising in lesions of hypertrophic lichen planus. To our knowledge, the concordant occurrence of these two disorders has not been previously reported.
Report of a Case
A 69-year-old woman was referred to our dermatology service for evaluation of three nodular growths of four weeks' duration on her right pretibial area. She also had had a pruritic eruption on the lower part of her legs for one year, with minimal response
Allen JV, Callen JP. Keratoacanthomas Arising in Hypertrophic Lichen PlanusA Case Report. Arch Dermatol. 1981;117(8):519–521. doi:10.1001/archderm.1981.01650080073035