Trichoblastic Carcinoma arising in Trichoblastoma: A Case Report

ABSTRACT

Trichoblastic carcinoma is a rare malignant neoplasm of follicular germ cell origin; to the best of our knowledge, only six trichoblastic carcinomas arising in trichoblastomas have appeared on the literature. We recently experienced a trichoblastic carcinoma arising in a long standing trichoblastoma. A 68-year old woman came to the hospital with a chief complaint of an ulcerated nodule on her face. The nodule, 1.1x0.9 cm with an asymmetrical configuration, had been present and unchanged for more than 20 years, however, it grew suddenly with painful burning sensation. An excisional biopsy was performed and disclosed a deeply invasive, highgrade carcinoma, which consisted of cohesive epithelial cells arranged in irregular plump or germinative cell nests of various sizes. However, at the periphery of the tumor was a benign trichoblastoma surrounded by perifollicular sheath. We believe that the present case is a trichoblastic carcinoma developed via malignant transformation of pre-existing trichoblastoma.