Subungual Exostosis: High-Resolution Ultrasound Findings

Abstract

Subungual exostosis is a rare solitary benign osteocartilaginous tumor that arises from the tuft of the distal phalanx beneath the nail. Because of its multiple clinical presentations, it is commonly underdiagnosed, resulting in delayed diagnosis and inadequate treatment. This report provides results from a 6-year retrospective study. All patients with a sonographic diagnosis of subungual exostosis confirmed surgically were selected. The data came from a series of 19 patient cases. Only 15.7% were clinically suspected. The median age was 21 years, and 63% were females. The sonographic findings were nail dystrophy, distal onycholysis, abnormal nail incurvation, subungual space enlargement, and the presence of hyperechogenic subungual image with acoustic shadowing that continued until the phalanx surface. Sonography provides an excellent diagnostic method for subungual exostosis, with findings that are pathognomonic.