Case reports: enlargement of a calcaneal osteochondroma after skeletal maturity.

Growth or radiologic modification of an osteochondroma after the epiphyseal plate closes suggests the diagnosis of malignant transformation to a chondrosarcoma. However, extensive growth of an osteochondroma in a skeletally mature patient whose tumor proved benign has been reported. We report a similar case in an adult who had a solitary osteochondroma of the calcaneus. The lesion showed marked growth and was removed. Histologic examination showed no evidence of malignancy, and there was no recurrence during the 4-year followup.