Trichodiscoma is a rare benign tumor first described by Pinkus et al in 1974. It represents a hamartomatous growth that recapitulates the hair disk, fibrous sheath, or papilla; produces a dome-shaped papule; and is characterized by a well-circumscribed proliferation of loosely packed fibroblasts and blood vessels. Mucin accumulation and a hair follicle at the margin of the lesion usually are found. It can occur either as a solitary papule or multiple tumors, with the face being the most commonly affected site.
