To the Editor.—
Keratoacanthomas are rapidly evolving benign tumors of the skin that occur on the hands and face of light-skinned elderly people. Histologically, they are very similar to cutaneous squamous cell carcinomas and it may be difficult to distinguish between the two. As keratoacanthomas arise mainly on sun-exposed sites, ultraviolet radiation is a probable etiologic factor. Other proposed contributing factors include viruses, oncogenic chemicals, and epidermal growth factor.Human papillomaviruses cause warts in man. They are also strongly associated with genital squamous cell carcinomas in normal individuals and with cutaneous squamous cell carcinomas in patients with epidermodysplasia verruciformis. More recently, human papillomavirus has been reported in cutaneous squamous cell carcinomas in immunosuppressed renal transplant recipients and the general population. These results have stimulated similar investigations of other skin lesions and several studies of keratoacanthomas have produced evidence for human papillomavirus involvement.In 1986, a German study detected human papillomavirus