Imaging features and follow-up of large extrahepatic portal vein aneurysm

Abstract

A 67-year-old man presented at our hospital for routine abdominal imaging studies before planned surgery for lung cancer. He had no obvious abdominal complaints. He had a history of chronic pancreatitis. Physical examination revealed no abnormal findings. Routine blood tests, including liverassociated enzymes, did not show any remarkable findings. We performed ultrasound (US) imaging, which demonstrated a 5.44.3-cm, round-shaped anechoic lesion at the hepatic hilum. Color Doppler US imaging showed bidirectional color due to circular flow within this lesion (A, arrows). Abdominal contrast-enhanced multidetector computed tomography (CT) and CT angiography with three-dimensional reconstructions using maximum-intensity projection (B, white arrow) and volume-rendering technique (Cover) confirmed the diagnosis of a saccular aneurysm at the truncus of the portal vein close to its bifurcation. Pancreatic calcifications were also present (B, black arrow). Complementary magnetic resonance imaging angiography showed the aneurysm with no abnormality of the liver and spleen. Axial maximum-intensity projection reformatted sections demonstrated that right and left branches of portal vein were normal (C, arrows). Thus, our patient was considered to have an acquired extrahepatic portal vein aneurysm (PVA) due to his history and imaging features of pancreatitis. Two years after the diagnosis, the aneurysm had not grown in size. Because our patient had no serious complaints or liver disease, surgical procedures had not been used.