Retroperitoneal mixed-type perinephric liposarcoma: A case report

A 66-year-old man, with abdominal distention, was referred to our department for the treatment of an abdominal tumor. Contrast computed tomogram and magnetic resonance imaging revealed a large retroperitoneal fatty tissue mass with calcification measured about 25 cm in diameter. The tumor, displacing the jejunum and the descending colon, was diagnosed as a liposarcoma. The previous contrast computed tomogram showed the abnormal signal in the left renal capsule, suggesting that the tumor was originated from the perinephric tissue. A complete excision of the tumor with concomitant resection of the left kidney was performed in September, 2009. The tumor did not involve other organs and weighed 5.88 kg. Histological examination disclosed retroperitoneal mixed-type liposarcoma composed of well-differentiated and dedifferentiated type. The patient did not consent to receive any adjuvant therapy. Neither local recurrence nor metastasis has been seen at 5 months after the operation.