A Giant Retroperitoneal Liposarcoma Encasing the Entire Left Kidney and Adherent to Adjacent Structures: A Case Report

Retroperitoneal liposarcoma is a rare tumor. The dimension and weight of liposarcoma are variable; those over 20 kg are called ‘giant liposarcoma’. Herein, we report giant retroperitoneal liposarcoma measuring 45 cm in diameter and 25 kg in weight encasing the entire left kidney and adherent to adjacent structures. A 71-year-old woman presented for a regular checkup. Image study revealed a huge mass probably indicative of retroperitoneal liposarcoma encasing the entire left kidney and adherent to adjacent structures. We performed an organ-preserving surgical removal. The pathologic report was liposarcoma. At postoperative month 16, a follow-up CT revealed a locally recurrent tumor. The patient underwent surgical removal of the newly discovered mass. After the second surgery, the patient underwent regular follow-up CT for approximately 12 months, and to date, there has been no evidence of tumor recurrence. High-grade liposarcoma shows sensitivity to radiation therapy. However, the toxic effect of radiation therapy limits this option by treatment modality. The use of chemotherapy is also controversial. As a result, complete resection is the gold standard treatment. Here, we report a giant retroperitoneal liposarcoma encasing the entire left kidney and adherent to adjacent structures, describe successful organ-preserving surgical removal and discuss prognosis.