Bile duct cancer, also known as cholangiocarcinoma, is a rare but aggressive cancer that develops in the bile ducts — the tubes that carry bile from the liver to the small intestine to aid digestion.

It can occur in different parts of the bile duct system:

• Intrahepatic – inside the liver
• Perihilar (hilar) – where bile ducts exit the liver
• Distal (extrahepatic) – outside the liver, closer to the intestine

This cancer is often diagnosed at an advanced stage because early symptoms are usually mild or absent. Early detection can significantly improve treatment outcomes.