[A case of leiomyosarcoma of the inferior vena cava].

A case of primary leiomyosarcoma of the inferior vena cava was reported. The patient, a 74-year-old man, consulted our hospital with complaints of back pain and abdominal mass in right flank. Probe laparotomy revealed a tumor situated in the retroperitoneum and multiple metastatic nodules in the liver. Biopsy was performed and diagnosed as leiomyosarcoma. He was intensively treated with antineoplastic chemotherapy, but his condition gradually aggravated. He died 4 months after admission. The autopsy revealed a right retroperitoneal mass (17 X 12 X 18 cm in size, 1,340 g in weight) that showed a yellowish appearance. There was also a thumb-tip sized tumor with a stalk in the lumen of inferior vena cava. Both tumors grew in continuity with each other through the wall of inferior vena cava. The tumors were diagnosed as leiomyosarcoma, which derived from inferior vena cava.