Abstract
In 1934, Ferguson Smith1described a self-healing squamous-cell epithelioma in the skin of a man 23 years of age. In 1955, Ereaux and associates2reported a case in which there were widespread self-healing epithelial tumors in the skin of a white man 41 years of age that were considered keratoacanthomas. The clinical and histologic characteristics of this lesion have been described.2-18A new classification of keratoacanthomas in three histological types, Types 1, 2, and 3, has been suggested recently by Ghadially.19 In considering the etiology of the localized type of keratoacanthoma, Anderson,2in the discussion of Ereaux's paper, says, "One is impressed . . . as to the frequent history of preceding trauma, such as a cut, scratch, or the squeezing of a blackhead. There is no doubt that very similar, if not identical, lesions occur in those exposed to tar." Actinic or