Adenocarcinoma
Nearly all cases of gallbladder and bile duct cancer are adenocarcinomas, which means they occur in gland-like cells that secrete fluids, mucus or digestive juices. In addition to the bile ducts and gallbladder, these cells are found in many organs of the body including the lungs, colon, pancreas, prostate and breasts.
Extrahapatic cholangiocarcinoma
Bile duct cancers are described by the location of the bile ducts where it began. Extrahepatic refers to the bile ducts that are outside of the liver, including:
- Hilar bile duct cancer (also called Klatskin tumor) occurs in the common hepatic duct, where all the ducts within the liver converge to exit the liver.
- Distal bile duct cancer occurs in the common bile duct which carries bile leaving the gallbladder through the cystic duct and from the common hepatic duct to the duodenum, the first part of the small intestine.
Intrahepatic cholangiocarcinoma
Cancer that occurs in the branches of ducts within the liver are called intrahepatic.
Papillary adenocarcinoma (or papillary cancer)
Papillary cancer occurs when the cancer cells grow into finger-like projections. Although this growth type is very rare, they are less likely to spread to the liver or lymph nodes, and have a better prognosis.
Other rare types of cancer may also begin in the biliary system. For example, sarcoma, adenosquamous carcinoma and squamous cell carcinoma may occur (very rarely) in the gallbladder.