Obstruction of the abdominal aorta by a primary retroperitoneal tumor.

An angiographically demonstrated case of total occlusion of the abdominal aorta by a malignant retroperitoneal tumor is presented. Surgical exploration revealed a diffuse tumor of the retroperitoneum involving the wall and lumen of the abdominal aorta and vena cava, respectively. Histologic and ultrastructural evaluation of the tumor established a diagnosis of malignant fibrous histiocytoma. Total occlusion of the abdominal aorta thus represents another angiographic finding in retroperitoneal tumors.