血管外皮細胞瘤是一種罕見的腫瘤，它可以發生在全身的任何一處，其中以下肢及後腹腔是最常發生的位置。我們報告一例骨盆腔巨大血管外皮細胞瘤，此瘤壓迫膀胱並且產生兩側腎水腫。此瘤重達980公克，並被成功地手術切除；並且回顧文獻。

Hemangiopericytoma is a solid and solitary tumor that may occur anywhere in the body. It is very rare and is often found in the retroperitoneum or lower extremities. This report describes a 53-year old man with a large retroperitoneal hemangiopericytoma in the pelvis, which displaced the urinary bladder and caused bilateral hydronephrosis. The tumor was successfully excised and weighed 980 grams. Literature was reviewed in the mean time.