Complete spontaneous regression of an extrahepatic portal vein aneurysm

Primary portal venous aneurysms are rare; however, they are the most common visceral venous aneurysms, and their pathogenesis is not fully understood. Complications include thrombosis, rupture, and mass effect on adjacent structures. The optimal management of these patients is not known. We describe a patient whose large (6-cm) portal vein aneurysm underwent complete spontaneous regression over several years of serial observation. To our knowledge, this observation has not been reported in the English literature.