A case of clonorchiasis with focal intrahepatic duct dilatation mimicking an intrahepatic cholangiocarcinoma

Abstract

Biliary strictures can be caused by various diseases. Intrahepatic duct (IHD) strictures are usually related to IHD stones and cholangitis. However, focal IHD strictures without IHD stones often create diagnostic problems. Parasitic diseases such as clonorchiasis can be a rare cause of an IHD stricture. Human clonorchiasis (Clonorchis sinensis infection) is an endemic parasitic disease in Eastern Asia, including Korea, and patients acquire the infestation by eating raw fish. On radiological examinations, clonorchiasis shows typically diffuse, minimal, or mild dilatation of the small IHD, particularly in the periphery, without dilatation of the extrahepatic duct. However, diagnosis of clonorchiasis can sometimes be difficult when radiological changes are atypical. We report a case of focal left IHD dilatation caused by clonorchiasis that was confused with a malignancy.

Keywords: Clonorchiasis; Dilatation; Intrahepatic bile duct; Stricture.

Fig. 1

Contrast-enhanced computed tomography scan finding. It shows the dilatation of left intrahepatic bile duct without mass or intrahepatic stone.

Fig. 2

Magnetic resonance cholangiopancreatography findings. (A) Axial T2 weighted image shows the marked dilatation and stricture (arrow) of left intrahepatic bile duct. (B) Coronal T2 weighted image shows the marked dilatation and stricture (arrow) of left intrahepatic bile duct. There is no evidence of stone and thickeness of duct wall at stricture segment.

Fig. 3

Cholangiographic findings. (A) Cholangioscope is inserted via a percutaneous transhepatic route. Radiograph shows the focal stricture (arrow) and dilatation of left intrahepatic duct (IHD) without abnormality of extrahepatic and right IHD. (B) After removal of the fluke, there is no evidence of filling defect at the left IHD.

Fig. 4

Percutaneous transhepatic cholangioscopy findings. (A) Dark brown, soft obstructive mass is found at stricture site of left intrahepatic duct. (B) Flat, leaf-shaped worm indentified as Clonorchis sinensis is observed after extraction of bile sludge. (C) The fluke is extracted with an endocopic forcep. After removal, there is no obvious stricture and surface irregularity or abnormal tumor vessel is not seen.