ABSTRACT
INTRODUCTION Keratoacanthoma (KA) is a common and distinctive epidermal neoplasm that often demonstrates a growth pattern of rapid enlargement combined with histology often indistinguishable from that of an ordinary cutaneous squamous cell carcinoma (SCC). For this reason, it has been viewed as a cutaneous pseudomalignancy. Alternatively, KA may rarely be clinically aggressive, so perhaps it is safer to use Kwittken’s designation, keratocarcinoma. The diagnosis of KA requires that the clinician rule out the highly malignant de novo type of SCC. The solitary KA usually appears on sun-exposed regions of light-complexioned persons of middle age or older. I regard it as an aborted cancer that only rarely progresses into an aggressive SCC. Nevertheless, KA is quite unique in many ways, mandating a management approach that is often different from that of SCC.
