[A case of extrahepatic portal vein aneurysm with massive thrombosis].

A 59-year-old woman, who was given a diagnosis of portal vein aneurysm at another hospital 2 years previously, visited our institution complaining of abdominal pain in November 2005. Abdominal imaging including computed tomography and ultrasonography demonstrated that the portal vasculature had dilated to 5 cm in maximum dimension and its center was at the junction of the superior mesenteric vein and the splenic vein. Moreover, a large thrombus was seen in the portal vein, the superior mesenteric vein and the splenic vein. She was conservatively followed-up with warfarin. After 6 months, angiography revealed cavernous transformation around the portal vein was found with collateral flow toward the liver. At the time of writing the patient's condition is stable with neither extension of the thrombus nor constriction of the esophageal varices.