Radiological features of 24 periosteal chondrosarcomas

Objective. To report the imaging findings of 24 periosteal chondrosarcomas diagnosed, staged, treated and followed in a single institution, to analyze and define their pattern, and discuss their practical consequences. Design and patients. Plain films, 16 CT examinations and four MRI examinations were reviewed, and compared with the histological evaluation. Results. There were 20 men and four women, aged from 17 to 65 years. Twelve lesions involved the distal femoral metaphyses (8 posteriorly), five the proximal humerus, two the proximal metaphyses of the femur and two of the tibia, two the humeral shafts and one the iliac wing. Size varied from 4 to 11 cm. The cortex was always involved (thick, 15; thin, 13). Typical cartilaginous calcifications and cartilaginous lobules were very frequent. Radial thick periosteal bone formations (n=6) indicated calcifications between the lobules of cartilage. Medullary involvement was rare (n=2). All patients are alive and free of disease. Conclusions. Recognizing periosteal chondrosarcoma is of paramount importance because the prognosis is excellent after adequate local surgery alone. The patterns of other surface tumors of bone are usually different. Received: 31 October 2000 Revision requested: 7 November 2000 Revision received: 5 January 2001 Accepted: 9 January 2001