Chondrosarcoma arising in a cartilaginous area of previously irradiated fibrous dysplasis

A 40-year-old woman developed a chondrosarcoma in an area of fibrous dysplasia. There was extensive cartilage formation associated with her primary disease and a history of radiation therapy to the area 30 years before. Chondrosarcoma arising in fibrous dysplasia characterized by extensive cartilage formation has never been reported. The proliferating cartilage in this form of fibrous dysplasia may be similar to Ollier's disease in which chondrosarcoma is frequent. Because of this association, the effect of the patient's prior irradiation is unclear. Patients with fibrous dysplasia manifested by large quantities of cartilage should be considered at risk for the development of chondrosarcoma.