Abstract
Retroperitoneal liposarcoma is a rare soft-tissue malignancy that occurs in middle-aged to older males. In the present case, the tumor was so large that it occupied almost the entire abdominal cavity. With the help of a three-dimensional reconstruction technique, we completely resected the tumor, and the pathology showed that it was a well-differentiated sarcoma, and the tumor did not recur after one year of postoperative follow-up. We present the clinical, radiographic, and pathological findings of such a case.