Abstract
One case of primary, extraosseous osteogenic sarcoma in the retroperitoneal region is presented, which is the tenth case hitherto reported in the literature. The 3 females and 7 males reported had a median age at diagnosis of 591/2 years. The tumours were all large at diagnosis and the symptoms short and uncharacteristic. There was no characteristic set of laboratory or roentgenologic findings; 2 of the 10 cases had elevation of alkaline phosphatase, and in 4 cases roentgen examination revealed tumour calcifications. The prognosis was poor and 8 of the 10 patients died, with a median survival of 91/2 months. In 3 cases, surgery was supplemented by chemotherapy without obvious improvement in survival.