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

Abstract

Background: 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.

Materials and methods: We retrospectively reviewed all cases from our institution received between 2000 and 2008 for any that reported a tumor within a tattoo.

Results: 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.

Conclusions: 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.