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

Abstract

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.

The changes in the expression levels of follicular markers in keratoacanthoma depend on the stage: keratoacanthoma is a follicular neoplasm exhibiting infundibular/isthmic differentiation without expression of CK15

“…47 The upper segment, which consists of infundibulum and isthmus, is permanent, and does not change during the hair cycle. 48 The hair follicles in the welladvanced catagen or in the telogen phase of the cycle also consist only of infundibulum and isthmus.…”

Recurrent Keratoacanthomas Developing after Spontaneous Resolution

“…Therefore, most "recurrences" of KA are considered to represent a reactive process in the proliferation phase rather than neoplastic changes or remnants of the neoplastic cells (5,12,13). In fact, the development of KAs has been reported to occur at sites of various types of trauma, including thorn injuries, dog scratches, tattoos and burn scars (10,14,15).…”

Localized Chronic Fibrosing Vasculitis in a Tattoo

“…Squamous cell carcinoma (SCC), keratoacanthoma, and pseudoepitheliomatous hyperplasia have been described in tattoos. 22 It is important to distinguish tattoo-associated epidermal hyperplasia from bona fide neoplasm. Separation may be difficult without an adequate clinical history.…”