This paper reports a case of Caroli's disease confined to the left lob
e of the liver that mimicked left portal vein thrombosis on MRI studie
s because of the very high signal-intensity on T1-weighted images of i
ntrahepatic pigmented calculi. The preoperative diagnosis was a cholan
giocarcinoma infiltrating the left hepatic bile duct and portal branch
. The final macroscopic and histological diagnosis was Caroli's diseas
e of the left liver lobe with wide: enlarged left bile duct containing
multiple pigmented calculi.