Extrahepatic bile duct cancer is a rare disease in which cancer cells form in the ducts that are outside the liver. The extrahepatic bile duct is made up of two parts:
- The common hepatic duct, which is also called the perihilar part of the extrahepatic duct.
- The common bile duct, which is also called the distal part of the extrahepatic duct.
Risk factors for extrahepatic bile duct cancer include the following disorders:
- Primary sclerosing cholangitis.
- Chronic ulcerative colitis.
- Choledochal cysts.
- Infection with a Chinese liver fluke parasite.
Source: National Cancer Institute