Folliculosebaceous cystic hamartoma with hair shaft fragments

We describe herein a 57-year-old Japanese male with a folliculosebaceous cystic hamartoma (FCH) presenting several hair shaft fragments in the cyst. Clinically, a skin-colored, dome-shaped, hard nodule, 5 x 4 mm in diameter was observed on the antitragus of his left ear. Histological examination revealed a large cystic structure surrounded by multiple mature sebaceous lobules and rudimentary hair follicules in the middle of the dermis. The cystic structure contained laminated orthokeratotic keratin and several hair shaft fragments. The fibrous stroma invaded the sebaceous lobules and obvious clefts were seen around the folliculosebaceous units located in the dermis. These features are characteristic histological findings of FCH. To our knowledge, this case is unusual with the presence of hair shaft fragments within the cystic structure. In addition, we discuss the histopathological findings of FCH and also review other cases of FCH in the literature.