bile duct cancer

What Is Bile Duct Cancer?

Bile duct cancer is a cancer that starts in the bile duct. In order to understand this cancer, it helps to know about the normal structure and function of the bile duct. About the bile duct The bile duct is a thin tube, about 4 to 5 inches long, that reaches from the liver to the small intestine. The major function of the bile duct is to transport a fluid called bile from the liver and gallbladder to the small intestine, where it helps digest the fats in foods. Different parts of the bile duct system have different names. In the liver, it begins as many tiny tubes (ductules) where bile collects from the liver cells. The ductules come together to form small ducts, which then merge into larger ducts and eventually the left and right hepatic ducts. These ducts exit from the liver and join to form the common hepatic duct. About one third of the way along the length of the bile duct, the gallbladder (a small organ that stores bile) attaches by a small duct called the cystic duct. The combined duct is called the common bile duct. The common bile duct passes through part of the pancreas before it empties into the first part of the small intestine (the duodenum), next to where the pancreatic duct also enters the small intestine. Types of bile duct cancers Cancers can develop in any part of the bile duct and, based on their location, are divided into 3 groups. Cancers in these different areas may cause different symptoms. Intrahepatic bile duct cancers: These cancers develop in the smaller bile duct branches inside the liver. They can sometimes be confused with cancers that start in the liver cells, which are called hepatocellular carcinomas, and are often treated the same way. Only about 1 out of 10 bile duct cancers are intrahepatic. Hilar (also called perihilar) bile duct cancers: These cancers develop where the hepatic ducts have joined and are just leaving the liver. They are also called Klatskin tumors. These are the most common type of bile duct cancer. Distal bile duct cancers: These bile duct cancers are found further down the bile duct, closer to the small intestine. More than 95% of bile duct cancers are of the adenocarcinoma type. Adenocarcinomas are cancers of glandular cells that can develop in several organs of the body. Bile duct adenocarcinomas develop from the mucus glands that line the inside of the duct. Cholangiocarcinoma is another name for a bile duct adenocarcinoma. Not all bile duct tumors are cancerous. Bile duct hamartomas and bile duct adenomas are benign (non-cancerous) tumors and, therefore, are not discussed further in this document.
How Is Bile Duct Cancer Diagnosed?

Most bile duct cancers are not found until patients go to a doctor because they have symptoms. Signs and symptoms of bile duct cancer Signs and symptoms may not be present until the later stages of bile duct cancer, but in some cases they may lead to an early diagnosis. If you go to your doctor when you first notice symptoms, your cancer might be diagnosed at an early stage, when it is most treatable. When bile duct cancer does cause symptoms, it is usually due to blockage of the bile duct. Jaundice: This is the most common symptom of bile duct cancer. Jaundice occurs when the liver cannot get rid of bile, and one of the chemicals in bile called bilirubin "backs up" into the bloodstream. Bilirubin is greenish yellow and colors all the body tissues, including the skin and the white part of the eyes, making people with this condition begin to look yellow. It is important to realize that most cases of jaundice are not caused by cancer. It is more often due to hepatitis (inflammation of the liver) or a gallstone that has traveled to the bile duct. But whenever jaundice occurs, a doctor should be seen right away. Itching: Excess bilirubin in the blood can also reach the skin, which can cause itching. Most people with bile duct cancer notice itching. Abdominal pain: Early bile duct cancers usually do not cause pain, but more advanced cancers may lead to abdominal pain, especially below the ribs on the right side. Loss of appetite/weight loss: People with bile duct cancer may not feel hungry and may unintentionally lose weight. Fever: Some people with bile duct cancer develop fevers. Light colored stools/dark urine: Bilirubin contributes to the brown color of bowel movements, so the blockage of its flow into the intestine might lighten the color of one's stool. Bilirubin can also come out in the urine and turn it dark. Nausea/vomiting: This is not a common symptom of bile duct cancer, but it may be seen in people who develop an infection of the gallbladder (cholangitis) as a result of bile duct blockage. It is often seen along with a fever. These are symptoms and signs of bile duct cancer, but it is important to remember that they are more likely to be caused by non-cancerous diseases. For example, people with gallstones may have many of these same symptoms. There are many causes of abdominal pain that are far more common than bile duct cancer. And hepatitis (infection of the liver by a virus) is a much more common cause of jaundice. Still, if you have any of these problems, it's important to see your doctor right away so the cause can be found and treated, if needed. History and physical exam If there is reason to suspect that you have bile duct cancer, your doctor will want to take a complete medical history to check for symptoms and risk factors, including your family history. A physical exam is done to look for signs of bile duct cancer and other health problems. If bile duct cancer is suspected, the exam will focus mostly on the abdomen to check for any masses, tenderness, or build up of fluid. The skin and the white part of the eyes will be checked for jaundice (a yellowish color). If symptoms and/or the results of the physical exam suggest bile duct cancer might be present, more involved tests will likely be done. These may include lab tests, imaging tests, and other procedures. Blood tests Tests of liver and gallbladder function: The doctor may order lab tests to find out how much bilirubin is in the blood. Bilirubin is the chemical that gives the bile its yellow color. Problems in the bile duct, gallbladder, or liver may cause too much bilirubin to remain in the blood. A high bilirubin count tells the doctor that there may be problems with the bile duct, gallbladder, or liver. The doctor may also order tests for other substances in your blood, such as albumin, alkaline phosphatase, AST, ALT, and GGT, that can also give an indication of bile duct, gallbladder, or liver disease. Although elevations of these substances may point to blockage of the bile duct, they cannot show if it is due to cancer or some other reason. Tumor markers: Tumor markers are substances made by cancer cells that can sometimes be found in the blood. People with bile duct cancer may have high blood levels of the carcinoembryonic antigen (CEA) and CA 19-9 tumor markers. High amounts of these substances often mean that there is cancer, but the absence of these markers does not mean there is no cancer, since not all cancers make them. Imaging tests Imaging tests use x-rays, magnetic fields, or sound waves to create pictures of the inside of your body. Imaging tests may be done for a number of reasons, including to help find a suspicious area that might be cancerous, to learn how far cancer may have spread, and to help find out if treatment has been effective. Imaging tests can often identify and locate a bile duct blockage. But they often do not reveal whether the blockage is due to a tumor or a benign problem such as scarring. Ultrasonography (ultrasound) Ultrasound is often the first imaging test done in people who have symptoms such as jaundice or pain in the right upper part of their abdomen. For this test, a small instrument called a transducer emits sound waves and picks up their echoes as they bounce off internal organs. The echoes are converted by a computer into a black-and-white image that is displayed on a video screen. The echoes produced by most tumors differ from those of normal tissue. The patterns of echoes can help distinguish between some types of benign and malignant tumors. This is a very easy procedure to have done that does not use radiation. For an ultrasound exam, you simply lie on a table while the doctor or ultrasound technician places the transducer (which is shaped like a wand) on the skin over the part of your body being looked at. Usually, the skin is first lubricated with gel. Endoscopic or laparoscopic ultrasound: These relatively new techniques allow the doctor to place the ultrasound transducer inside the body and closer to the bile duct to produce more detailed images than a standard ultrasound. The transducer is on the end of a thin, lighted tube that has an attached viewing device (an endoscope or laparoscope). The tube is either passed through the mouth and down through the stomach and near the bile duct (endoscopic ultrasound) or through a surgical incision (cut) in the side of the patient's body (laparoscopic ultrasound). If there is a tumor, the doctor may be able to tell how far it has grown and spread, which can help in planning for surgery. Ultrasound may be able to show if nearby lymph nodes are enlarged, which may be a sign that cancer has reached them. It may also be used to guide a needle into a suspicious node so that cells can be removed (biopsied) and viewed under a microscope. Computed tomography (CT) scan The CT scan is an x-ray procedure that produces detailed cross-sectional images of your body. Instead of taking one x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these into images of slices of the part of your body that is being studied. Prior to the scan, you may be asked to drink a contrast solution and/or get an intravenous (IV) injection of a contrast dye that helps better outline abnormal areas in the body. You may need an IV line through which the contrast dye is injected. The injection can cause some flushing (redness and warm feeling). Some people are allergic and get hives or, rarely, more serious reactions like trouble breathing and low blood pressure. Be sure to tell the doctor if you have ever had a reaction to any contrast material used for x-rays. You need to lie still on a table while the scan is being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that completely surrounds the table. You might feel a bit confined by the ring you have to lie in while the pictures are being taken. In recent years, spiral CT (also known as helical CT) has become available in many medical centers. This type of CT scan uses a faster machine. The scanner part of the machine rotates around the body continuously, allowing doctors to collect the images much more quickly than standard CT. As a result, you do not have to hold your breath for as long while the image is taken. This lowers the chance of blurred images occurring as a result of breathing motion. It also lowers the dose of radiation received during the test. The slices it images are thinner, which yields more detailed pictures. CT scans can have several uses: They are often used to help make the initial diagnosis of bile duct cancer by showing tumors in the area. They can be helpful in staging the cancer (determining the extent of its spread). CT scans can also show the organs near the bile duct (especially the liver), as well as lymph nodes and distant organs where cancer may have spread to. This can help to find out if surgery is a good treatment option. CT scans can also be used to guide a biopsy needle precisely into a suspected tumor or metastasis. For this procedure, called a CT-guided needle biopsy, the patient remains on the CT scanning table, while a radiologist advances a biopsy needle through the skin and toward the location of the mass. CT scans are repeated until the needle is within the mass. A biopsy sample is then removed and looked at under a microscope. Magnetic resonance imaging (MRI) scan Like CT scans, MRI scans provide detailed images of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into very detailed images of parts of the body. A contrast material called gadolinium is often injected into a vein before the scan to better see details. MRI scans provide a great deal of detail and can be very helpful in looking at the bile ducts and nearby organs. Sometimes they can help tell a benign tumor from a malignant one. Special types of MRI scans may also be used in people who may have bile duct cancer. MR cholangiopancreatography(MRCP) can be used to look at the bile ducts and is described below in the section on cholangiography. MR angiography (MRA) looks at blood vessels and is mentioned below in the section on angiography. MRI scans may be a little more uncomfortable than CT scans. They take longer -- often up to an hour. You may be placed inside a large cylindrical tube, which is confining and can upset people with a fear of enclosed spaces. Newer, "open" MRI machines can help with this if needed. The MRI machine makes buzzing and clicking noises that you may find disturbing. Some places will provide earplugs to help block this out. Cholangiography A cholangiogram is an imaging test that looks specifically at the bile ducts to see if they are blocked, narrowed, or dilated. They can be used in people who may have bile duct cancer to look for abnormalities and to help plan surgery. There are several types of cholangiograms, which have different pros and cons. Endoscopic retrograde cholangiopancreatography (ERCP): In this procedure, a doctor passes a long, flexible tube (endoscope) down the patient's throat, through the stomach and first part of the small intestine, and into the common bile duct. The patient is usually sedated so that the procedure is not uncomfortable. A small amount of contrast dye is passed through the tube to help outline the bile duct and pancreatic duct as x-rays are taken. The images can show narrowing or blockage of the bile duct or pancreatic duct. This test is more invasive than MRCP (see below), but one advantage of using it is that the doctor can use the endoscope to take samples of cells or fluid to be viewed under a microscope. It can also be used to place a stent (a small tube) into a duct to help keep it open. Magnetic resonance cholangiopancreatography (MRCP): This is a less invasive way to image the bile ducts using the same type of machine used for standard MRI scans. It does not require an endoscope or an IV infusion of a contrast agent. Percutaneous transhepatic cholangiography (PTC): In this procedure, the doctor places a thin, hollow needle through the skin and into a bile duct within the liver. (A local anesthetic is used to numb the area before inserting the needle.) A contrast dye is then injected through the needle, and x-rays are taken as it passes through the bile ducts. Like ERCP, this approach can also be used to take samples of fluid or tissues or to place stents (small, hollow tubes) in the bile duct to help keep it open. Positron emission tomography (PET) scan For a PET scan, a form of radioactive sugar (known as fluorodeoxyglucose or FDG) is injected into the blood. The amount of radioactivity used is very low. Because cancer cells in the body grow rapidly, they absorb large amounts of the radioactive sugar. A short time later, a special camera is used to create a picture of areas of radioactivity in the body. The picture is not finely detailed like a CT or MRI scan, but it can provide helpful information about your whole body. A PET scan can sometimes help tell if a bile duct obstruction is caused by a cancer or not, although not all doctors agree on how useful it is for bile duct cancer. PET scans can also be useful if your doctor thinks the cancer may have spread (or returned after treatment) but doesn't know where. PET scans can be used instead of several other imaging tests because they scan your whole body. Some newer machines are able to perform both a PET and CT scan at the same time (PET/CT scan). This allows the radiologist to compare areas of higher radioactivity on the PET with the appearance of that area on the CT. Angiography Angiography is an x-ray procedure for looking at blood vessels. For this test, a small amount of contrast dye is injected into an artery to outline blood vessels before x-ray images are taken. The images allow the doctors to see if blood flow in an area is blocked or hindered by a tumor, and they can show any abnormal blood vessels in the area. Angiography can also show whether a bile duct cancer has grown through the walls of certain blood vessels. This information is mainly used to help surgeons decide whether a cancer can be removed and to help plan the operation. Angiography can be uncomfortable because the radiologist who does the procedure has to put a small catheter (a flexible hollow tube) into the artery leading to the bile duct to inject the dye. Usually the catheter is put into an artery in your inner thigh and threaded up into the artery supplying the bile duct. A local anesthetic is often used to numb the area before inserting the catheter. Then the dye is injected quickly to outline all the vessels while the x-rays are being taken. Angiography may also be done with a CT scanner (CT angiography) or an MRI scanner (MR angiography). These techniques give information about the blood vessels without the need for a catheter, although you may still need an IV line so that a contrast dye can be injected into the bloodstream during the imaging. Other tests Doctors may also place special instruments (endoscopes) into the body to get a more direct look at the bile duct and surrounding areas. The scopes may be passed through small surgical incisions or through natural body openings such as the mouth. Laparoscopy In a laparoscopic procedure, a doctor inserts a thin tube with a light and a small video camera on the end (a laparoscope) through the abdominal wall to view the bile duct, gallbladder, liver, and other organs and tissues in the area. The tube is inserted through a small incision (cut) in the front of the abdomen. (Sometimes more than one cut is made.) This procedure is typically done in the operating room while you are under general anesthesia (in a deep sleep). Laparoscopy provides a view of organs that can help in planning surgery or other treatments, and can help doctors confirm the stage (extent) of the cancer. If needed, doctors can also insert instruments through the incisions to remove small biopsy samples to be looked at under a microscope. Cholangioscopy In this relatively new procedure, the doctor passes a very thin fiber-optic tube into the bile duct through the mouth after routine ERCP or through a needle placed into a liver bile duct through the abdominal wall. From there it can be maneuvered into the bile duct. This allows the doctor to see any tumors and even biopsy them. Biopsy Although imaging tests can suggest that a bile duct cancer is likely to be present, in many cases a sample of bile duct cells or tissue is removed (biopsied) and looked at under a microscope to be sure of the diagnosis. But a biopsy may not always be done before surgery for a possible bile duct cancer. If imaging tests (ultrasound, CT or MRI scans, cholangiography, etc.) suggest there is a tumor in the bile duct, the doctor may decide to proceed directly to surgery and to treat it as a bile duct cancer (see the section, "How is bile duct cancer treated?"). Types of biopsies There are several ways to take biopsy samples of the bile duct. If cholangiography (ERCP or PTC) is being done, a sample of bile may be collected during the procedure to look for tumor cells within the fluid. Bile duct cells and tiny fragments of bile duct tissue can also be sampled by biliary brushing. Instead of injecting contrast dye and taking x-ray pictures (as for ERCP or PTC), the doctor advances a small brush with a long, flexible handle through the endoscope or needle. The end of the brush is used to scrape cells and small tissue fragments from the lining of the bile duct, which are then looked at under a microscope. Biopsy specimens can also be taken during cholangioscopy. This allows the doctor to view the inside surface of the bile duct and take samples of suspicious areas. In other cases, a needle biopsy may be done. For this test, a thin, hollow needle is inserted through the skin and into the tumor without making a surgical incision. (The skin is numbed first with a local anesthetic.) The needle is usually guided into place using ultrasound or CT scanning. With this approach, the needle is slowly moved forward while doctors check its position by viewing images provided by one of these imaging tests. When the images show that the needle is in the tumor, a sample is drawn into the needle and sent to the lab to be viewed under a microscope. In most cases, this done as a fine needle aspiration (FNA) biopsy, which uses a very thin needle attached to a syringe to suck out (aspirate) a sample of cells. If this isn't successful, a core needle biopsy may be done, which uses a slightly larger needle to get a bigger sample.

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