The Clinical, Histopathological and Radiological Findings of Subungual Exostosis / 대한피부과학회지

ABSTRACT

BACKGROUND: Subungual exostosis is a rare, solitary, benign bony tumor of the distal phalanx. It occurs mainly in the great toe and less frequently in the other toes and fingers. It may cause nail deformity and pain. OBJECTIVE: We wanted to describe the clinical, histopathological and radiological features and the recurrence after treatment of subungual exostosis. METHODS: A total of 12 patients who were diagnosed with subungual exostosis at our hospital from 1997 through 2007 were evaluated. RESULTS: There were seven females and five males. The average age of the patients at the time of surgery was 24.2+/-9.2 years. The mean duration of symptoms was 11+/-6.0 months. All the patients presented with a solitary, fixed, hard exophytic tumor beneath the nail plate. Eight patients (67%) presented with a lesion on the great toe, three patients (25%) with a lesion on the other toes and one patient (8%) with a lesion on the thumb. The histopathology revealed a fibrocartilaginous cap, enchondral ossification and calcification in all the patients and islands of mature trabecular bone in ten patients (83%). The radiographic picture showed a typical pattern of a bony excrescence arising from the dorsal aspect of the distal phalanx. All the patients were treated with surgical excision of the lesion and eleven patients (92%) showed good results. One patient (8%) had a local recurrence and she underwent subsequent excision. No additional local recurrences were observed. CONCLUSION: Subungual exostosis is unfamiliar to most dermatologists, and it can be difficult to diagnose in some cases. When a subungual mass is observed, subungual exostosis should be considered in the differential diagnosis and subsequent radiographic studies along with histologic studies are recommended.