[Intrahepatic portal vein aneurysm: report of two cases]

We present two cases of intrahepatic portal vein aneurysm. The lesions were seen as low density mass on precontrast CT, hypoechoic mass with connecting vascular structures on ultrasonogram and dilatated branch of portal vein on MRI. Definite diagnosis were obtained by arteriogram. Only 15 cases of portal vein aneurysm were reported in Japan up to now in the literature.