Solitary enchondromas: is radiographic follow-up sufficient in patients with asymptomatic lesions?

Enchondromas are benign cartilaginous tumours and rarely transform into chondrosarcomas. Curettage is usually performed, and a low rate of complications is assumed. We analysed retrospectively data from 73 patients with enchondromas treated by curettage with respect to symptoms, therapy, complications and recurrences. All patients were treated by curettage of the tumour, in most cases followed by cancellous bone grafting. Twenty-three percent of the patients presented a complication. There were two recurrences but no malignant transformations in the follow-up period. During the same time period 29 patients with chondrosarcomas were treated, including two secondary chondrosarcomas. One had a recurrence of a benign enchondroma of the metacarpal and developed a pulmonary metastasis from a chondrosarcoma. The other was a patient with Ollier's disease who had a secondary chondrosarcoma of the radius. Malignant transformation of a solitary enchondroma to a chondrosarcoma is rare. On the other hand the complication rate of enchondroma curettage is considerable. Regular radiological follow-up of asymptomatic enchondromas may therefore be the better option.