ON THIS PAGE: You will find some basic information about this disease and the parts of the body it may affect. This is the first page of Cancer.Net’s Guide to Bile Duct Cancer (Cholangiocarcinoma). Use the menu to see other pages. Think of that menu as a roadmap for this entire guide.

Bile duct cancer begins when healthy cells in the bile duct change and grow out of control, forming a mass called a tumor. A tumor can be benign or cancerous. A benign tumor can grow but will not spread. A cancerous tumor is malignant, meaning it can grow and spread to other parts of the body. Bile duct cancer is also called cholangiocarcinoma. Cancers of the biliary system, which is made up of the bile duct, gallbladder, and liver, are generally not common, especially in the United States.

About the bile duct

The bile duct is a 4-inch- to 5-inch-long tube that connects the liver and gallbladder to the small intestine. The bile duct allows bile to flow into the small intestine. Bile is a liquid that is made in the liver and stored in the gallbladder. It helps break down fats found in foods. It also helps the body get rid of the waste material that is filtered out of the bloodstream by the liver.

The bile duct starts in the liver. Inside the liver, smaller tubes (or intrahepatic bile ducts), like small blood vessels, drain bile from the cells in the liver into larger and larger branches. These branches end in a tube called the common bile duct. The end of the bile duct empties into the small intestine.

The gallbladder is an organ that holds bile until food reaches the intestines. It is attached to the common bile duct by a small duct, called the cystic duct. This attachment is located about one-third of the way down the bile duct from the liver.

See illustrations of the bile duct.

Types of bile duct cancer

Cancer can occur in any part of the bile duct. Doctors identify the type of bile duct cancer by the location of the tumor in the body:

• Extrahepatic cholangiocarcinoma. The part of the bile duct that is located outside of the liver is called "extrahepatic." This location is where bile duct cancer is most commonly found. It tends to be the most treatable form of the disease.

• Hilar cholangiocarcinoma. Another relatively common site for bile duct cancer is the point where the right and left hepatic ducts join. A tumor that starts in this area is also sometimes called a Klatskin’s tumor.

• Intrahepatic cholangiocarcinoma. About 5% to 10% of bile duct cancers are "intrahepatic." These are located inside the liver.

This section is about primary bile duct cancer, which is cancer that starts in the bile duct. For information about cancer that began in another part of the body and has spread to the bile duct, please see Cancer.Net’s guide for that type of cancer.

The next section in this guide is Statistics. It helps explain the number of people who are diagnosed with bile duct cancer and general survival rates. Use the menu to choose a different section to read in this guide.