Keratoacanthoma: case presentation and discussion.

Keratoacanthomas are rather common, rapid growing skin tumors, in which may occur as solitary lesions or in the form of multiple lesions. Multiple forms involve the palms of soles, and their source is unclear. On area where hair grows, these lesions originate from the infundibular areas. Many environmental and traumatic influences are implicated as potential etiologic factors. Keratoacanthomas should be differentiated clinically and histologically from squamous cell carcinomas, prurigo nodularis, and chronic paronychia. Treatment varies according to the type of lesions, but solitary lesions should be excised in toto.