ABSTRACT

Keratoacanthomas are distinct skin lesions that occur most often as fast-growing, solitary, cutaneous tumors in sun-exposed areas in elderly, fair-skinned patients. A major problem in dealing with keratoacanthomas is the difficulty of clinically and histologically differentiating them from well-differentiated squamous cell carcinoma. It is essential to differentiate keratoacanthoma and squamous cell carcinoma as soon and accurately as possible. But the difficulty can be encountered by some pathologists in making a histological distinction between the two entities, in some cases. There is an increasing trend in the dermatologic arena to regard keratoacanthoma as a variant of squamous cell carcinoma or within the malignant spectrum, rather than as a benign entity. The phenomenon of squamous cell carcinoma arising in a keratoacanthoma has important consequences for the management of keratoacanthoma. We believe that all lesions suspected of being keratoacanthomas should be treated by surgical excision and not left to spontaneous involution.