Dupuytren's (subungual) exostosis.

Because it may produce a bewildering array of histologic patterns, the clinical entity of subungual exostosis (Dupuytren's exostosis), is sometimes confused with chondrosarcoma. However, this lesion is a distinct entity. It begins as a reactive growth of cellular fibrous tissue and metaplastic cartilage, which undergoes enchondral ossification. The rate of growth may be exuberant, but it is limited. We present a series of 15 cases as well as a review of the literature. Postadolescents and young adults are most commonly affected, and the majority of cases (80%) occur on the dorsal-medial aspect of the great toe. Trauma, whether chronic or acute, and infection are frequent inciting factors. The radiologic picture is consistent and can be diagnostic. In more than half our cases, chondrosarcoma was suspected initially. However, if the entire clinical picture is evaluated, the histologic findings should not lead to confusion with a malignant process. This acquired exostosis is benign; local excision is curative. However, recurrence is common (53%) after incomplete excision or when the lesion has not achieved full maturation.