Dual Tumors — Trichoadenoma of Nikolowski and Melanocytic Naevi

Abstract

Trichoadenoma is a rare benign tumor with differentiation to hair follicle. There are several reports of a melanocytic naevus seen in association with another benign adnexal tumor with hair follicular differentiation - trichoepithelioma. However, there is, to the best of our knowledge, only one case of a collision tumor of trichoadenoma with a melanocytic naevus - with an admixture of the two components. Trichoadenoma and trichoepithelioma are considered parts of a spectrum, with trichoadenoma being better differentiated than trichoepithelioma. Herein we present an unusual case of dual tumors - trichoadenoma and melanocytic naevi of the face. Unlike the previously reported case, the current case had simultaneous occurrence of trichoadenoma and naevi at different locations. The exact cause for the association of these tumors - trichoadenoma and melanocytic naevi - is uncertain. Key Messages : Benign dermal adnexal tumors like trichoepithelioma and trichoadenoma may be found in association with melanocytic naevi. Keywords: Dermal adnexal tumor, Trichoadenoma, Melanocytic Naevi