A 62-year-old man from rural Thailand has a 6 cm intrahepatic mass with irregular borders and satellite nodules. Biopsy shows malignant glands embedded in dense desmoplastic stroma. Which exposure is a recognized risk factor for this tumor?

• A Chronic carriage of hepatitis D virus alone
• B Prior infection with Schistosoma japonicum
• C Chronic infection with Opisthorchis viverrini ✓
• D Long-term therapy with ursodeoxycholic acid

Explanation

This is intrahepatic cholangiocarcinoma, an adenocarcinoma of intrahepatic bile ducts with desmoplastic stroma. Infection with the liver flukes Opisthorchis viverrini and Clonorchis sinensis, endemic in Southeast Asia, is a well-established risk factor, along with primary sclerosing cholangitis, thorotrast exposure, and choledochal cysts. Schistosomiasis predisposes to squamous carcinoma of the bladder, not cholangiocarcinoma. Ursodeoxycholic acid has been studied for chemoprevention and is not carcinogenic.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.