This is the first part of our series about the condition based on our patient booklet “Fast Facts for Patient and Supporters: Cholangiocarcinoma”. This article focuses on:
- What is cholangiocarcinoma?
- How does cholangiocarcinoma develop?
- What are the symptoms of cholangiocarcinoma?
Cholangiocarcinoma is a cancer of the body’s hepatobiliary system, which includes the liver, gallbladder and tubes called bile ducts.
The hepatobiliary system makes, stores and transports bile. Bile helps the body break down fat in the diet and get rid of waste from the body.
The liver makes bile, which is collected in small tubes (ductules) and funneled into increasingly larger ducts as it is carried through the liver. As the bile leaves the liver, the duct system merges into left and right hepatic ducts. These two ducts leave the liver and join at the hilum to form the common hepatic duct.
The gallbladder stores bile. It connects to the hepatobiliary system about one-third of the way down the common hepatic duct, via the cystic duct. This duct is now called the common bile duct, and it continues through the pancreas before reaching the small intestine (the destination for the bile).
There are two main types of cholangiocarcinoma: intrahepatic and extrahepatic.
- Intrahepatic cholangiocarcinoma occurs in the bile ducts inside the liver.
- Extrahepatic cholangiocarcinoma occurs in the bile ducts outside the liver. These drain bile into the small intestine.
A perihilar tumor is an extrahepatic cholangiocarcinoma that develops at or near the junction of the left and right bile ducts (the hilum). These tumors were previously called Klatskin tumors.
A distal tumor develops in the common bile duct.
Cholangiocarcinomas are rare tumors, accounting for only about 3 in every 100 cancers in the gastrointestinal system. Perihilar tumors are the most common type of cholangiocarcinoma (approximately half), followed by distal tumors (approximately 4 in every 10), and intrahepatic tumors (approximately 1 in every 10).
Development of Cholangiocarcinoma
The starting point for cholangiocarcinoma is a harmful change (mutation) to the DNA in cells in the bile duct. One of the effects is that cells start to grow and divide without the usual controls. Eventually, a mass of cells forms a tumor.
Doctors do not know exactly what causes the changes in the DNA, though some medical conditions and lifestyle factors increase the risk.
|Medical conditions and lifestyle factors that increase the risk
|• Bile duct: primary sclerosing cholangitis, primary biliary cirrhosis, bild duct stones or cysts
|• Digestive system: infllammatory bowel disease (Crohn's disease or ulcerative colitis), chronic pancreatitis
|• Chronic liver disease: cirrhosis, hemochromatosis, fatty liver disease (non-alcoholic fatty liver disease or non-alcoholic steatohepatitis), hepatitis B or C
|• High alcohol intake
|• Infection with liver fluke (a problem in some South-East Asian countries)
Symptoms of Cholangiocarcinoma
The symptoms of cholangiocarcinoma can vary from person to person. Intrahepatic and extrahepatic cholangiocarcinomas may cause different symptoms. If the tumor blocks the flow of bile, infections can cause fever, chills and yellowing of the skin and eyes (jaundice).
Symptoms may be caused by the tumor mass in the liver. Abdominal pain, bloating, weight loss, fatigue, jaundice, itching, or sweats at night are common symptoms.
If symptoms are mild or absent, the cancer may be discovered by chance during blood tests, imaging or surgery for other reasons.
The skin or eyes may become yellow (jaundice) and the skin may become itchy. Urine color may be darker than usual. Stools may become pale. A person may feel fatigued (extremely tired) and lose weight.
Information based on Fast Facts for Patients and Supporters: Cholangiocarcinoma (Karger, 2021).