Onychomatricoma on the fourth toenail: A rare tumor in a rare localization.

Onychomatricoma is a rare benign tumor of the nail matrix, characterized by finger-like projections that invade the nail plate. The fingernails of Caucasian women are most commonly affected. Because this tumor can easily mimic other more prevalent ungual diseases, it is crucial to be acquainted with its characteristic clinical and histopathologic features. The authors present a case of a 40-year-old man with an onychomatrichoma in the fourth left toenail, which was initially misdiagnosed and treated as onychomycosis.