Keratoacanthoma developing in sites of previous trauma: A report of two cases and review of the literature

Keratoacanthoma is a common benign squamous neoplasm that only rarely progresses to metastic carcinoma. The cause of keratoacanthoma is unclear, however, suspected causes include ultraviolet light, genetic factors, immunosuppression, chemical carcinogens, viruses, and trauma. Keratoacanthomas have been reported only rarely to arise in sites of previous trauma. We report 2 cases of keratoacanthomas arising shortly after episodes of cutaneous trauma and provide a review of the literature of similar cases previously reported. It is likely that an interaction exists between a variety of factors in the development of keratoacanthomas; however, it appears that a predilection exists for these lesions to arise in trauma sites.