S1961 Primary Retroperitoneal Mass Due to a Well-Differentiated Giant Liposarcoma

Introduction: Primary retroperitoneal masses are frequently malignant and may be due to sarcoma, lymphoma, primary germ cell, and neurogenic tumors. Retroperitoneal fibrosis and other benign etiologies comprise a smaller subset of retroperitoneal lesions. Case description/methods: A 45-year-old previously healthy man presented with a 12-month history of insidious onset and progressive unintentiona…