A 59-year-old man develops jaundice and pruritus. He has no abdominal pain, and on physical examination he is icteric, the liver span is 10 cm, and no masses are felt. Ultrasound reveals dilated intrahepatic bile ducts. He undergoes endoscopic retrograde cholangiopancreatography (ERCP), which suggests a holangiocarcinoma. Which of the following is the most likely predisposing factor for cholangiocarcinoma?
(A) smoking
(B) excess alcohol intake
© chronic hepatitis B virus (HBV) infection
(D) history of ulcerative colitis or sclerosing
cholangitis
(E) gallstones
solution
(D) Worldwide, the presence of liver flukes (e.g., Clonorchis sinensis) is the most likely predisposing factor for cholangiocarcinoma. Part of this increased risk is caused by the development of hepatolithiasis. The highest rate of cholangiocarcinoma is found in Southeast Asia. It is thought that liver flukes and a diet high in nitrosamine are the prime reasons for this. In North America, primary sclerosing cholangitis and chronic ulcerative colitis are the most common predisposing factors. Cholelithiasis, alcohol, smoking, and chronic hepatitis B are not known to be risk factors