[Aneurysmal malformation of the extrahepatic portal vein].

Malformations of extrahepatic portal vein are rare. We report a case of extrahepatic portal vein aneurysm which was incidentally found in a female patient, aged 67, suffering from alcoholic cirrhosis. This malformation was located at the portal bifurcation and presented ultrasonically as an oval, non-echogenic, parahilar mass, 38 mm in diameter, and in continuity with the portal trunk. On CT-scan and angiography, diagnosis of portal vein aneurysm located at its extrahepatic segment was confirmed. The cause of extrahepatic portal vein aneurysm remains controversial. A congenital and/or acquired origin induced by portal hypertension explains their development.