A 27-year-post-partum female with known cryptogenic cirrhosis for 2 years presented with abdominal distension and swollen feet for 4 weeks. Abdominal ultrasound revealed features of portal hypertension with grossly dilated portal vein including its right and left branches. Subsequent abdominal magnetic resonance imaging test confirmed the diagnosis of a portal vein aneurysm (PVA). Flow sensitive axial image (Panel A) arrow points to aneurysmal dilatation of ascending branch of the left portal vein (>3 cm) and coronal contrast enhanced magnetic resonance angiographic imaging (Panel B) arrow points to markedly dilated portal vein (21 mm).
Portal vein aneurysm is considered a rarity, with only approximately 70 cases described in the literature (1). Barzilai and Kleckner were the first to report portal vein aneurysm, in 1956. Although portal vein aneurysm is still rare, previously unrecognized portal vein aneurysm is now detected more frequently with the increasing use of cross-sectional imaging in the evaluation of abdominal complaints (2). Two major causes, congenital and acquired, have been proposed. Strong support is given to the theory that they are acquired because a significant number of portal vein aneurysms are detected in patients with underlying hepatocellular disease and portal hypertension. In most cases of disease-related forms of portal vein aneurysm, the patients are asymptomatic, and surgery is unnecessary therefore careful monitoring is the best treatment (3).