A RARE CASE OF A GIANT RETROPERITONEAL RECURRENT LIPOSARCOMA

We report the case of a giant retroperitoneal liposarcoma, with two rare histological subtypes: pleomorphic subtype at initial surgical resection, and dedifferentiated subtype at the recurrence. A 61-year-old male patient, presented at the University Emergency Hospital Bucharest, for progressive enlargement of the abdomen. The exploratory laparotomy found a deforming mass in the retroperitoneal area, with medial displacement of the left colon, from the splenic flexure to the recto-sigmoid junction. After assessing the resectability of the tumor, it was decided and performed an en-bloc excision of the tumor, without multiorgan resection and with macroscopic free safety margins. Due to the intersection with the genital vessels, their resection was imposed. The tumor was trefoil-shaped, with a diameter of 35 cm. After 7 months of chemotherapy, tumor recurrence occured, within the same location, confirmed as a dedifferentiated subtype. The same surgical procedure was performed, and the oncologist decided to continue with a more aggressive chemotherapy. Pleomorphic liposarcoma has a high rate of recurrence and has a high resistantce at chemotherapy. Due to its deep retroperitoneal location, the relations with the inferior vena cava, the aorta and the genital vessels are essential, in some cases multiorgan resections being necessary.The case presents a rare malignant tumor, a 35 cm diameter retroperitoneal liposarcoma, highly resistant to chemotherapy and with a high recurrence rate.