A Case of Trichilemmal Carcinoma

Trichilemmal carcinoma is a rare tumor that is located predominantly on sun-exposed skin of the elderly. It is thought to be related to the external root sheath of the hair follicle and the malignant counterpart of a trichilemmoma.

We report a case of trichilemmal carcinoma in a 88-year-old woman who had a 10 year history of a single, dark brown tumor on the right preauricular region. In her past medical history, it had been excised twice at a private clinic without a histopathological evaluation and recurred 2 years later. Histopathological findings showed atypical clear cells resembling those of the outer root sheath. Tumor cells showed PAS-positive cytoplasm. Immunohistochemistry revealed positive high molecular weight cytokeratin expression.

To our knowledge, this is the second case of trichilemmal carcinoma in the Korean literature. (Ann Dermatol 100) 175178, 1998).