A solitary, exophytic, crateriform lesion on the mandibular retromolar gingiva.

A solitary, intraoral keratoacanthoma discovered on the mandibular left retromolar mucosa in a 64-year-old black male is reported. This is the eighth lesion of this type reported to date. The patient had stopped smoking 5 years earlier and gave no history of an occupation involving pitch or tar. The lesion had the typical clinical and microscopic features of a keratoacanthoma. A 6-month recall examination showed no evidence of recurrence of the lesion.