  What Is Bile Duct Cancer?  To help you understand what is
happening when you have cancer, it helps to understand how your
body works normally. Our bodies are made up of tiny building
blocks called cells. Normal cells grow and multiply when the
body needs them, and die out when the body does not need them.
Cancer is made up of abnormal cells that grow whether your body
needs them or not.  Illustration of liver and biliary system
Click to Enlarge  Bile duct cancer can develop in any part of
the bile ducts. The bile ducts are thin tubes that transport
bile from the liver to the gallbladder and from the gallbladder
to the small intestine. This cancer may cause different
symptoms, depending on where it starts.    • Perihilar or
proximal bile duct cancers. These develop where the main right
and left bile ducts join as they are leaving the liver. Most
bile duct cancers are in this area.    • Distal bile duct
cancers. These typically develop in the common bile duct near
the first part of the small intestine.    • I