Bile Duct Cancer: Diagnosis
How is bile duct cancer diagnosed?
If your healthcare provider thinks you might have bile duct cancer, you will need certain exams and tests to be sure. Diagnosing bile duct cancer starts with your healthcare provider asking you questions. He or she will ask you about your health history, your symptoms, risk factors, and family history of disease. Your healthcare provider will also give you a physical exam.
What tests might I need?
You may have one or more of the following tests:
Liver function and liver enzyme blood tests
Tumor markers blood test
Endoscopic or laparoscopic ultrasound
Magnetic resonance cholangiopancreatography (MRCP)
Endoscopic retrograde cholangiopancreatography (ERCP)
Percutaneous transhepatic cholangiography (PTC)
A biopsy is when a small amount of tissue is removed to be checked. To see if you have cancer, your doctor will likely need to take a small piece of the tumor from your bile duct. The type of biopsy done can depend on where a tumor is. The biopsy may be done as part of another procedure, such as ERCP or PTC. Or it may be done using a thin, hollow needle placed through the skin and into the tumor. The needle is guided into place using computed tomography (CT) scans or ultrasound.
A doctor called a pathologist looks at the biopsy samples under a microscope. This doctor specializes in looking for cancer cells to confirm a diagnosis.
A biopsy may not be done if the doctor can confirm bile duct cancer based on imaging tests. Or a biopsy may not be done if the cancer is in a place that would be very hard to biopsy. In these cases, treatment for cancer may be done instead. If surgery is done, the diagnosis can be confirmed from tissue taken during surgery.
Blood tests may be done to check these:
Liver function. Liver function tests are blood tests that check how well your liver is working or if it has been injured. Bile duct cancer can affect liver function tests. The best liver function tests to check for cancer are bilirubin, prothrombin time (international normalized ration or INR), and albumin. The doctor takes a small sample of your blood and checks its level of bilirubin. This is to see if there is a blockage in your bile duct system. Another test looks for a substance called alkaline phosphatase. Damaged bile duct cells release this.
Liver enzymes. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), and gamma-glutamyl transpeptidase (GST) are tests of liver enzymes. They are done to check for liver inflammation, irritation, or bile duct blockage. If you have high levels of AP and GST, it may mean that something is blocking a bile duct. The test can’t show if the blockage is due to cancer or something else.
Tumor markers. This is another type of blood test. These tests look for increases in certain substances called tumor markers. Some cancers make these substances. If you have bile duct cancer, two markers may be increased. They are carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9). If your tumor markers are high, it may mean that you have cancer or another disease. A normal level of tumor markers doesn’t always mean there is no cancer. Your doctor may repeat this test during your treatment to see how your treatment is working.
Ultrasound. This test uses sound waves to look for problems in the bile duct. This is done with a wand-like instrument placed on the skin over your belly. The sound waves bounce off body parts and send back signals. A computer then receives the signals and creates an image of the inside of the body. This test is very helpful in showing growths inside the body and learning more about them. If a mass is a fluid-filled sac (cyst) it’s probably not cancer. If it’s a solid tumor, it is more likely to be cancer. Ultrasound can show enlarged bile ducts. And it can show growths that are larger than 1 centimeter (cm), which may be cancer.
Endoscopic or laparoscopic ultrasound. Your doctor may also do an endoscopic or laparoscopic ultrasound. These tests use a thin, lighted tube called an endoscope. Your doctor may insert the endoscope through your mouth and into your stomach near the bile duct area. Or you may have surgery to make a small cut in your side. This is done so that your doctor can see inside your abdomen using a tool called a laparoscope. Both procedures allow the doctor to get closer to the bile ducts to use ultrasound. This allows for more detailed images. These methods may be used to help remove tissue for a biopsy. Your doctor can also use this test to see more clearly if the cancer has spread.
Endoscopic retrograde cholangiopancreatography (ERCP). This test is one of the best ways to find bile duct cancer that is closer to the pancreas. During this test, the doctor passes a flexible tube called an endoscope down the throat, through the stomach, and into the small intestine. The doctor then passes a smaller scope through the endoscope to inject dye into the common bile duct. The dye shows any problems on X-rays. Your doctor can also use this test to get a biopsy. The doctor inserts a small brush with a long, flexible handle through an endoscope. The brush is then used to scrape cells and small samples of tissue. During an ERCP, the doctor may also insert small tubes called stents to reopen a duct blocked by cancer.
Magnetic resonance cholangiopancreatography (MRCP). This test creates detailed pictures of the bile ducts. It’s done using the same type of machine used for standard MRI scans. Unlike ERCP, it doesn’t use an endoscope or contrast dye. This test has fewer risks than ERCP, so doctors often use MRCP if the only purpose of the test is to image the bile ducts. But MRCP can’t be used to get biopsy samples to place stents.
Percutaneous transhepatic cholangiography (PTC). The doctor may do PTC if ERCP is not able to reach the site of blockage. It’s a more invasive procedure, but PTC gives a better picture of the bile ducts. It is also very useful for bile duct cancer that’s closer to or inside the liver. It can show the exact location and size of the tumor. This test can also help show if the tumor can be removed by surgery. For this test, the doctor uses a needle placed through the skin and into your liver to inject dye into your bile duct system. Then X-rays can show any abnormalities or blockages in your bile ducts. The doctor can also take a biopsy. If the doctor sees a blockage, he or she may place a special type of stent to bypass the bile blockage and allow the bile to temporarily flow into a bile bag outside of the body. This is called percutaneous transhepatic bile drainage (PTBD).
Getting your test results
When your healthcare provider has the results of your tests, he or she will contact you with the results. Your provider will talk with you about other tests you may need if bile duct cancer is found. Make sure you understand the results and what follow-up you need.
March 21, 2017
Hepatobiliary Cancers, National Comprehensive Cancer Network, Up To Date. Clinical Manifestations and Diagnosis of Cholangiocarcinoma
Alteri, Rick, MD,Welch, Annette, MNS, OCN