Synovial chondrosarcoma: report of a case and review of the literature.

Primary synovial chondromatosis is a relatively uncommon condition. Synovial chondrosarcoma is considered to be very rare and it is not always clear whether the sarcoma develops by malignant transformation of synovial chondromatosis or whether it arises de novo. Differentiation of the two conditions on clinical and radiographic features is not possible and on histological criteria can be difficult. We report the case of a 59-year-old man who, 4 years after a synovectomy for synovial chondromatosis, developed a synovial chondrosarcoma of the hip. The literature is reviewed.