Abstract
Peribiliary cysts involve cystic dilatation and necroinflammatory change in the peribiliary glandular tissue of the larger biliary tree in association with portal hypertension or severe hepatobiliary disease. They are usually asymptomatic and found incidentally. However, rare cases causing symptoms or the mass effect of bile duct compression require differential diagnosis. They may be benign or malignant lesions resulting from narrowing of the bile duct and involving dilatation of the proximal intrahepatic bile duct. We recently encountered a case of peribiliary cysts associated with intrahepatic duct dilatation, and confirmed by surgery, and present the imaging and pathologic findings. Sonography and CT revealed the presence of multiple cystic lesions along the hepatic hilum, and the larger left portal tract and left intrahepatic ducts were dilated. Histopathologic examination indicated that the cysts were compressing the central bile duct.