Hilar cholangiocarcinoma occurs in the bile ducts just outside of the liver. This type is also called perihilar cholangiocarcinoma. Distal cholangiocarcinoma occurs in the portion of the bile duct nearest the small intestine. Cholangiocarcinoma is a type of tumor that is very difficult to treat. Cholangiocarcinoma care at Mayo Clinic
https://www.mayoclinic.org/diseases-conditions/cholangiocarcinoma/symptoms-causes/syc-20352408

