Differentiating keratoacanthoma from squamous cell carcinoma of the lower lip: an analysis of intraepithelial elastic fibers and intracytoplasmic glycogen

Abstract

Differentiation of keratoacanthoma from squamous cell carcinoma on the vermilion mucosa of the lower lip can sometimes be difficult. Two histopathologic features that are helpful in distinguishing between these two lesions when they occur on sun-exposed skin are the incidence of intraepithelial elastic fibers and the epithelial intracytoplasmic glycogen content. An analysis of thirty-one keratoacanthomas and twenty-eight squamous cell carcinomas from the vermillion mucosa of the lower lip indicates that while the incidence of intraepithelial elastic fibers and the tumor intracytoplasmic glycogen content are greater in keratoacanthomas, these features are not reliable for differentiating between the two lesions in this location.