Subungual exostosis: case report and review of the literature.

Subungual exostosis is typically a benign, acquired tumor of cartilaginous bone occurring on the medial surface of the distal hallux. A 16-year-old boy with subungual exostosis of his left great toe is presented. We evaluated the English language literature on this topic from 1857 to 1994; including our patient, 312 cases have been described. The diagnostic characteristics (histologic and radiologic), etiologic features, and therapeutic management were reviewed. Subungual exostosis more commonly affects women than men in a ratio of 2:1. Most lesions occur in the early twenties; however, a minimum of 51 (16%) of the 312 cases of subungual exostoses appeared in children 18 years of age or younger. Seventy percent of lesions occurred on the first hallux. There was frequently an association with trauma. The diagnosis of subungual exostosis may be suspected from the clinical presentation and confirmed with radiographic examination. The treatment is surgical.