Primary retroperitoneal liposarcoma: clinical and histological analysis of ten cases.

Retroperitoneal liposarcoma constitutes an uncommon and locally aggressive malignancy. We performed a retrospective analysis of 10 patients (6 males; mean age: 63.2+/-11 years) with histologically proven retroperitoneal liposarcoma seen at our institution between 1999 and 2007. Presence of a palpable abdominal mass was the main symptom at diagnosis. All patients underwent complete surgical resection. Negative microscopic margin was achieved in four cases. Histological analysis revealed the following subtypes: well-differentiated (6 cases), dedifferentiated (two cases), pleomorphic, and myxoid/round cell (one case each). Concomitant resection of adjacent organs was needed in five cases. Half of the patients developed tumor recurrence, mainly limited to the retroperitoneum or abdominal cavity. The mean recurrence-free survival was 43.3 months (95%CI: 25.7-60.8), with 3- and 5-year overall survival rates of 79% and 61%, respectively. Patients undergoing complete resection with clear margins showed a near-significant trend toward increased recurrence-free survival (62.9 vs. 29.3 months; P=0.06).