Tattoo‐associated keratoacanthomas: a series of 8 patients with 11 keratoacanthomas

Abstract

Keratoacanthoma is interpreted by many dermatopathologists in the United States as a form of squamous cell carcinoma that can spontaneously involute. Rare examples arising in tattoos have been reported in the literature. We retrospectively reviewed all cases from our institution received between 2000 and 2008 for any that reported a tumor within a tattoo. We identified eight patients with keratoacanthomas that arose within tattoos. One of the patients had four separate keratoacanthomas arising within two separate tattoos. Red tattoo ink was associated with 82% of the keratoacanthomas. Keratoacanthomas are more common than previously reported in tattoos and are easily misinterpreted. The association with red tattoo ink suggests a form of hypersensitivity-associated with adnexal hyperplasia. Tattoo-associated squamous tumors with innocuous nuclei, infundibulocystic structures, adnexal hyperplasia, and signs of regression should be reported as keratoacanthomas rather than as variants of squamous cell carcinoma.