Solitary keratoacanthoma involving upper lip: a diagnostic dilemma - case report and a brief review

Keratoacanthoma (KA) is a benign epithelial proliferative lesion which frequently occurs on the sun exposed areas of the skin. KA originates within the pilosebaceous apparatus of the skin and may be solitary or multiple. Solitary KA can be difficult to differentiate from squamous cell carcinoma (SCC) both clinically and microscopically. However, the clinical course of the lesion and its ability to self involute makes it a distinct clinical entity. Solitary KA appears on the vermilion border of the lower lips with some frequency. A case of keratoacanthoma involving the upper lip is reported presenting as an exophytic growth that resolved after excisional biopsy. Photo- graphic documentation of the case along with relevant management protocol is discussed. The article emphasizes the significance of recognizing such lesion and discriminating it from SCC thus carrying diagnostic and therapeutic implications. However, in case of dilemma it is prudent to assume that the lesion is SCC unless proved otherwise clinically or histologically