Portal venous aneurysms--report of 4 cases.

Portal venous aneurysms are rare and are usually discovered as incidental findings on abdominal imaging studies. Although most are asymptomatic, they may occasionally cause symptoms of compression of an adjacent structure, thrombosis, or bleeding. Treatment is usually not necessary and conservative follow-up is suggested. We present four patients with portal system aneurysms. One patient had a 10.5 cm thrombosed aneurysm, one had a right 3.5 cm intrahepatic portal aneurysm, one patient had a symptomatic 4 cm splenic artery aneurysm, which was repaired, and one patient had a 4 cm aneurysm at the confluence of the splenic and portal veins.