Abstract
Hemangiopericytoma, a vasogenic tumor which can occur anywhere there are blood vessels and which is a relatively rare disease, was reported by Staut and Murray in 1942. Some cases of hemangiopericytoma have a clinically malignant course such as regional relapse and metastatsis to the liver or lung. especially in the case of retroperitoneal tumor, discovery is difficult until the tumor itself has grown to a rather large size, and furthermore, there are many cases in which it is very difficult to excise the tumor totally due to the rich supply of blood vessels attached to it. We have experienced a case of hemangiopericytoma in which preoperative embolization using Gelfoam was performed to control intraoperative bleeding and in which the tumor was completely excised together with the adhesive ureter and a part of the urinary bladder upon surgery. With regard to treatment of such cases, it is considered that angiography would be useful in diagnosis and that the tumor should be treated as a malignant tumor upon surgery.
