[Mesenteric-portal confluence aneurysm].

The authors take interest in the portal aneurysm about the observation of a 52 year-old woman with an echographic lesion in the head of the pancreas. Radiological examination was done with abdominal CT and MRI. Because of no accurate diagnosis, an explorative laparotomy was done and showed an aneurysm at the junction of the portal and superior mesenteric veins. These lesions are rare: they can be acquired particularly with underlying hepatocellular diseases and portal hypertension; they can be congenital due to an incomplete obliteration of the right vitelline vein. If asymptomatic, only a close surveillance must be proposed.