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 examinati ons 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 p roximal humerus, two the proximal metaphyses of the femur and two of the ti bia, two the humeral shafts and one the iliac wing. Size varied from 4 to 1 1 cm. The cortex was always involved (thick, 15; thin, 13). Typical cartila ginous 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 a re alive and free of disease. Conclusions. Recognizing periosteal chondrosarcoma is of paramount importan ce because the prognosis is excellent after adequate local surgery alone. T he patterns of other surface tumors of bone are usually different.