<prompt> Symptoms from a retroperitoneal sarcoma are usually produced byBleeding into the tumor massCompression of adjacent tissuesInvasion of retroperitoneal organsMetastases to retroperitoneal lymph nodes  <response>: Retroperitoneal sarcomas grow along fascial planes and envelop rather than invade retroperitoneal organs.vLymph node metastases are unusual. The tumor does not usually grow rapidly enough to outgrow its blood supply, and major hemorrhage into the tumor mass is uncommon. 