Abstract
A 73 year old man was hospitalized three times in a semicomatose condition but responded each time to intravenous glucose. X-rays showed a large soft-tissue mass in the abdomen, displacing the bowel and ureters, and nodular and linear densities in both lung fields. At laparotomy, extensive hemorrhage during biopsy precluded removal of the mass, but resection was undertaken later on the assumption that the tumor was benign. The mass was difficult to remove and proved to be a large retroperitoneal neurofibrosarcoma of low-grade malignancy.