General Information About Extrahepatic Bile Duct Cancer
Key Points for This Section
- Extrahepatic bile duct cancer is a rare disease in which malignant (cancer) cells form in the ducts that are outside the liver.
- Having colitis or certain liver diseases can increase the risk of extrahepatic bile duct cancer.
- Possible signs of extrahepatic bile duct cancer include jaundice and pain.
- Tests that examine the bile duct and liver are used to detect (find) and diagnose extrahepatic bile duct cancer.
- Certain factors affect prognosis (chance of recovery) and treatment options.
The extrahepatic bile duct is made up of two parts:
- Common hepatic duct, which is also called the perihilar part of the extrahepatic duct.
- Common bile duct, which is also called the distal part of the extrahepatic duct.
The extrahepatic bile duct is part of a network of ducts (tubes) that connect the liver, gallbladder, and small intestine. This network begins in the liver where many small ducts collect bile (a fluid made by the liver to break down fats during digestion). The small ducts come together to form the right and left hepatic ducts, which lead out of the liver. The two ducts join outside the liver and form the common hepatic duct. Bile from the liver passes through the hepatic ducts, common hepatic duct and cystic duct and is stored in the gallbladder.
When food is being digested, bile stored in the gallbladder is released and passes through the cystic duct to the common bile duct and into the small intestine.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk with your doctor if you think you may be at risk. Risk factors include having any of the following disorders:
- Primary sclerosing cholangitis.
- Chronic ulcerative colitis.
- Choledochal cysts.
- Infection with a Chinese liver fluke parasite.
The following tests and procedures may be used:
- Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.
- CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. A spiral or helical CT scan makes detailed pictures of areas inside the body using an x-ray machine that scans the body in a spiral path.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
- PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.
- ERCP (endoscopic retrograde cholangiopancreatography): A procedure used to x-ray the ducts (tubes) that carry bile from the liver to the gallbladder and from the gallbladder to the small intestine. Sometimes bile duct cancer causes these ducts to narrow and block or slow the flow of bile, causing jaundice. An endoscope is passed through the mouth, esophagus, and stomach into the first part of the small intestine. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. A catheter (a smaller tube) is then inserted through the endoscope into the pancreatic ducts. A dye is injected through the catheter into the ducts and an x-ray is taken. If the ducts are blocked by a tumor, a fine tube may be inserted into the duct to unblock it. This tube (or stent) may be left in place to keep the duct open. Tissue samples may also be taken and checked under a microscope for signs of cancer.
- PTC (percutaneous transhepatic cholangiography): A procedure used to x-ray the liver and bile ducts. A thin needle is inserted through the skin below the ribs and into the liver. Dye is injected into the liver or bile ducts and an x-ray is taken. If a blockage is found, a thin, flexible tube called a stent is sometimes left in the liver to drain bile into the small intestine or a collection bag outside the body.
- Biopsy : The removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer. The sample may be taken using a thin needle inserted into the duct during an x-ray or ultrasound. This is called a fine-needle aspiration (FNA) biopsy. The biopsy is usually done during PTC or ERCP. Tissue, including part of a lymph node, may also be removed during surgery.
- Liver function tests : A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by the liver. A higher than normal amount of a substance can be a sign of liver disease that may be caused by extrahepatic bile duct cancer.
- Tumor marker test : A procedure in which a sample of blood, urine, or tissue is checked to measure the amounts of certain substances made by organs, tissues, or tumor cells in the body. Certain substances are linked to specific types of cancer when found in increased levels in the body. These are called tumor markers. Carcinoembryonic antigen (CEA) and CA 19-9 are associated with extrahepatic bile duct cancer when found in increased levels in the body.
- The stage of the cancer (whether it affects only the bile duct or has spread to other places in the body).
- Whether the tumor can be completely removed by surgery.
- Whether the tumor is in the upper or lower part of the duct.
- Whether the cancer has just been diagnosed or has recurred (come back).
Treatment options may also depend on the symptoms caused by the tumor. Extrahepatic bile duct cancer is usually found after it has spread and can rarely be removed completely by surgery. Palliative therapy may relieve symptoms and improve the patient's quality of life.