Cancers may be found in any portion of the bile duct. The location of the primary tumor (in or outside the liver) and the type of cell involved determine the specific type of cancer in the bile duct.
Extrahepatic bile duct cancer develops in the ducts outside of the liver. Nearly all bile duct cancers are extrahepatic, including:
- Adenocarcinomas, the typical type of extrahepatic bile duct cancer, develops in the mucous gland’s cells lining the innermost of the bile duct. Adenocarcinomas bring up about 95 percent of all bile duct cancers. Bile duct adenocarcinoma is also known as cholangiocarcinoma.
- Hilar (or perihilar) bile duct tumors, otherwise known as Klatskin cancer, develop where hepatic duct branches leave the liver. About two-thirds of all bile duct cancers are hilar or perihilar on a basis.
- Distal bile duct cancer develops beside the small intestine, at the opposite end of the duct from a perihilar tumor. About one-fourth of all bile duct cancers begin in this area.
Intrahepatic bile duct cancer starts in the liver, in the minor duct branches. Only about 5 percent to 10 percent of all bile duct cancers are intrahepatic. Intrahepatic bile duct cancers are frequently misdiagnosed as liver cancer, and both are commonly given treatment the same way.
Generally, bile duct cancer does not cause signs or manifestations until later in the course of the illness, but symptoms can usually occur earlier and lead to early analysis. Treatment may work better if the cancer is diagnosed early.
If bile duct cancer causes symptoms, this is usually due to a blockage of a bile duct. Symptoms tend to depend on whether the cancer is present in ducts within the liver (intrahepatic) or outside of the liver (extrahepatic) and include:
- Light-colored/greasy stools
- Darkened urine
- Loss of appetite
- Nausea and vomiting
- Abdominal pain
These are not typical signs of bile duct cancer but can occur in people who develop an infection (cholangitis) due to obstruction of the bile duct. These signs are also seen accompanied by fever.