Postoperative electron beam irradiation to prevent recurrence of refractory subungual exostosis: a case report.

Background: Subungual exostosis is a type of heterotopic ossification, which often has unclear margins. Therefore, marginal resection may cause recurrence and wide resection is sometimes required to achieve a complete cure. However, wide resection may cause postoperative nail deformity and revision of this deformity is generally difficult. The primary treatment of subungual exostosis is surgical treatment, and there have been no comprehensive reports on the efficacy of adjunctive treatments. Although postoperative electron beam irradiation has been successfully used after heterotopic ossification excision to prevent recurrence, there are no reports on the use of this procedure following subungual exostosis resection. Case Description: Herein, we report a case of refractory subungual exostosis that developed as a result of chronic irritation and inflammation caused by an ingrown nail and recurred after initial resection. We performed marginal resection of the lesion to preserve the nail matrix and nail bed as possible, a two-stage skin grafting procedure, and electron-beam irradiation to prevent recurrence. Conclusions: Excellent results were achieved both in terms of complete cure and cosmetic appearance, suggesting that electron-beam irradiation following refractory subungual exostosis excision may help prevent its recurrence. We expect a further study including many cases of subungual exostosis treated with postoperative electron-beam irradiation to be conducted.