Congenital Desmoplastic Trichoepithelioma: A Case Report

Summary: Desmoplastic trichoepithelioma is a rare benign skin tumor of follicular origin, typically appearing as an asymptomatic, firm, annular plaque with a raised border, usually on the face. Females are more commonly affected than males, with reported patient ages ranging from 8 to 79 years. Congenital onset of desmoplastic trichoepitheliomas is rare, and we found only one other case reported in the literature. This report presents a case of desmoplastic trichoepithelioma present at birth on the forehead of a healthy male infant born at term. Clinically, the lesion consisted of a 3 mm firm, mobile nodule with calcified white subcutaneous nodules, located just superior to the medial right eyebrow. Histopathologically, the lesion was small, symmetrical, reasonably demarcated, and dermal centered. Basaloid cords with minimal atypia embedded on a fibrous stroma were suggestive of recapitulation toward the developing follicular germ. Small milia-like cysts with multifocal calcifications tended toward the superficial aspect of the lesion and were suggestive of differentiation toward the primitive follicular infundibulum. Diminutive sebaceous structures also tended toward the superficial aspect and were further evidence of differentiation toward the developing follicular unit. This report describes a rare case of a congenital desmoplastic trichoepithelioma in a male infant.