Bile duct cancer, also known as cholangiocarcinoma, is a rare and aggressive form of cancer that originates in the bile ducts. The bile ducts are thin tubes that carry bile from the liver and gallbladder to the small intestine, helping in digestion.

There are three types of bile duct cancer:
1. Intrahepatic Cholangiocarcinoma: This type of bile duct cancer begins in the bile duct inside the liver.
2. Perihilar Cholangiocarcinoma: It originates at the hilum, where the left and right hepatic ducts join to form the common hepatic duct, which carries bile out of the liver.
3. Distal Cholangiocarcinoma: This type of bile duct