extrahepatic bile duct cancer (EK-struh-heh-PA-tik BILE dukt KAN-ser)
A rare cancer that forms in the part of the bile duct that is outside the liver. The bile duct is the tube that collects bile from the liver and joins a duct from the gallbladder to form the common bile duct, which carries bile into the small intestine when food is being digested.