[Three cases of retroperitoneal soft tissue sarcoma].

Soft tissue sarcomas (STS) are rare tumors that comprise only 1% of all malignancies. The retroperitoneum is an uncommon site of origin for them, accounting for about 10% of all STS. In case 1, a 30-year-old man complaining of chest pain was found to have a retroperitoneal tumor around the left kidney by computed tomography (CT). The tumor was removed along with the left kidney. Histologically, it was fibrosarcoma 3,000 g in weight. In case 2, a 31-year-old woman complaining of abdominal distension was found to have a retroperitoneal tumor by CT. The tumor was removed in the same way. It was undifferentiated sarcoma 2,000 g in weight. In case 3, a 73-year-old woman, who had no complaint was found to have mass in the left lateral region during follow up for cardiac failure. She was referred to our department for treatment of retroperitoneal tumor revealed by ultrasound and CT. The tumor was dedifferentiated liposarcoma 2,420 g in weight. All three patients had local recurrences, and two of them underwent a second surgical procedure.