Folliculosebaceous Cystic Hamartoma With Hair Shaft Fragments

The document described a case of a 57-year-old Japanese male with a folliculosebaceous cystic hamartoma (FCH) that contained hair shaft fragments within the cyst. The nodule was a 5 x 4 mm, skin-colored, dome-shaped, hard structure located on the antitragus of his left ear. Histological examination showed a large cystic structure with mature sebaceous lobules and rudimentary hair follicles, containing laminated orthokeratotic keratin and hair shaft fragments. The fibrous stroma invaded the sebaceous lobules, and clefts were observed around the folliculosebaceous units. This case was noted to be unusual due to the presence of hair shaft fragments in the cystic structure, and the report included a discussion of the histopathological findings and a review of other FCH cases in the literature.