[A Case of Giant Retroperitoneal Liposarcoma Resected after Trabectedin Chemotherapy].

The basic treatment for retroperitoneal liposarcoma is surgical therapy. Since the administration of trabectedin for soft tissue sarcoma has been approved, another option for soft tissue sarcoma treatment has been added. We report a case of radical resection after trabectedin therapy for initially unresectable retroperitoneal liposarcoma. A 61-year-old man was admitted to our hospital with an abdominal tumor. A tumor, about 50 cm in maximal diameter, that was not movable throughout the abdomen was observed. Computed tomography revealed a giant tumor almost occupying the entire abdomen, and he was diagnosed with retroperitoneal liposarcoma based on histopathological examination of a puncture specimen. Chemotherapy containing trabectedin was administered. At the end of 8 courses, he achieved stable disease. However, the movability improved, and surgery was performed. The procedure was tumor resection with right kidney, adrenal gland, and inferior vena cava resection. Histopathological examination revealed a mixed type of well differentiated type and dedifferentiated type. The patient is alive without recurrence 10 months after the surgery.