Risk factors for intra- and extrahepatic cholangiocarcinoma:
(1) choledochal cyst
(2) Caroli's disease
(3) cholangitis
(4) inflammatory bowel disease with chronic intraductal gallstone disease
(5) primary sclerosing cholangitis, with or without an inflammatory bowel disease
(6) biliary cirrhosis
(7) cholelithiasis
(8) alcoholic liver disease
(9) cirrhosis
(10) diabetes
(11) thyrotoxicosis
(12) chronic pancreatitis
(13) bile duct adenomas
(14) multiple biliary papillomatosis
(15) exposure to Thorotrast (thorium dioxide radiocontrast material)
(16) parasitic involvement of the bile ducts
(17) AIDS
Additional risk factors for intrahepatic cholangiocarcinoma include:
(1) obesity
(2) chronic non-alcoholic liver disease
(3) hepatitis C infection
(4) smoking
where:
• Adenomas at the ampulla of Vater have a high risk of malignant transformation. It could be debated whether to include them as bile duct carcinomas.
Limitations:
• Patients may develop carcinoma of the biliary system without identified risk factors.
