[Pilar sheath acanthoma].

Pilar sheath acanthoma is a rare, benign follicular hamartoma. A case is reported, and the histological and clinical features of this skin tumor are described. The tumor is elevated and characterized by a central punched-out area filled with amorphous whitish material. In contrast to the keratoacanthoma, which has a similar clinical appearance, pilar sheath acanthoma shows no spontaneous regression.