Giant recurrent mixed-type liposarcoma of the retroperitoneum: report of a case and review of literature.

Retroperitoneal liposarcoma is a rare tumor with an incidence of 2.5 per million individuals, especially tumors of mixed histologic pattern. We present a case of a 63-year-old woman with a history of slowly increasing abdominal volume over 2 years. The diagnosis of giant and multiple retroperitoneal mass suspected of liposarcoma was confirmed by computed tomography. The patient underwent resection of 7 tumor masses together weighing 5 kg. The microscopic diagnosis was mixed-type liposarcoma of the retroperitoneum. 8 months after surgery, the patient suffered multiple metastases in the liver and abdominal wall, and upper digestive tract hemorrhage. Although this type of tumor is rarely seen, tumor tissue should be thoroughly gathered and analyzed on histologic examination to reach final diagnosis. Knowledge of the subtype of liposarcoma is important for proper prognosis and treatment of the patient. To the best of our knowledge, this is the first report of mixed-type retroperitoneal liposarcoma with three components described in the English literature.