腹膜后间隙是后腹膜与腹后壁以及盆腔后壁肌肉群之间的广阔潜在间隙,这一间隙内组织松软,有利于肿瘤生长、扩散。腹膜后间隙组织来源复杂,所发生的肿瘤称原发性腹膜后肿瘤(prim aryretroperitonealtum ors,PRT),绝大多数为恶性,称原发性恶性腹膜后肿瘤(prim arym alignant retr The retroperitoneal space is a vast potential gap between the retroperitoneum and the posterior abdominal wall and the muscle mass of the posterior wall of the pelvic cavity. This interstitial tissue is soft and conducive to tumor growth and spread. The origin of retroperitoneal space tissue is complex. The tumors that occur are called prim aryrealcitonant tumors (PRTs), the vast majority of which are malignant, and are referred to as prim arym alignant retrorests