[Osteogenic sarcoma (report of 18 cases)].

Eighteen cases of osteogenic sarcoma of the long bones in the extremities were analyzed in this paper. The pathological basis of the X-ray signs was explained. It was suggested that solitary calcific shadow appearing near the knee joint in young individuals should alert the radiologist to the possibility of osteogenic sarcoma. The X-ray findings of osteogenic sarcoma were characterized by dissociation of osteolysis from ossification. Simultaneous bony destruction both inside and outside the cortex was one of the patterns of erosive bone destruction in osteogenic sarcoma. The distinction between benign and malignant bony spicules, the differences in the relationship between soft tissue mass and subcutaneous fat layer and that between osteomyelitis and the subcutaneous fat layer were discussed.