A 55-year-old man from eastern India with a long history of eating raw freshwater fish develops progressive jaundice and weight loss. Imaging shows intrahepatic ductal dilatation without a stone. Which parasite, residing in the biliary tree, is a recognised cause of cholangiocarcinoma?

• A Clonorchis sinensis ✓
• B Fasciola hepatica
• C Paragonimus westermani
• D Schistosoma mansoni

Explanation

Clonorchis sinensis, the Chinese liver fluke, inhabits the intrahepatic bile ducts where chronic inflammation and hyperplasia predispose to cholangiocarcinoma; Opisthorchis species behave similarly. Fasciola hepatica also lives in bile ducts but is associated with biliary obstruction and ectopic lesions rather than malignancy. Paragonimus is a lung fluke and Schistosoma mansoni causes periportal fibrosis and colonic disease. Diagnosis is by detecting small shouldered-operculum eggs in stool or bile.

Reference: Paniker's Textbook of Medical Parasitology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.