Retroperitoneal malignant mesenchymoma: a case report.

A case of a 37-year-old woman with a retroperitoneal tumor is reported. Angiography revealed that the tumor was partially supplied via an intercostal artery, suggesting that the cause of the tumor might be located in the rib. Histologically the tumor was diagnosed as a malignant mesenchymoma composed of chondrosarcoma and myxoid liposarcoma in addition to fibrosarcoma. The chondrosarcomatous element was predominant, a phenomenon which is extremely rare. Pulmonary metastases developed 8 mo after surgical removal of the tumor and the patient died of the disease 2 yr postoperatively.