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. You'll be asked about your health history, symptoms,
risk factors, and family history of disease. A physical exam will be done.
What tests might I need?
You may need to have one or more of these tests:
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Biopsy
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Blood tests, including tests for liver function, liver enzyme, and tumor markers
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Ultrasound
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Endoscopic or laparoscopic ultrasound
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Magnetic resonance cholangiopancreatography (MRCP)
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Endoscopic retrograde cholangiopancreatography (ERCP)
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Percutaneous transhepatic cholangiography (PTC)
Biopsy
A biopsy is when a tiny bit of tissue is taken out and tested in a lab. Your healthcare
provider will likely need to take a small piece of the tumor from your bile duct to
know if you have cancer. The type of biopsy done depends on where the tumor is. The
biopsy may be done as part of another procedure, such as ERCP or PTC (see below).
Or it may be done using a thin, hollow needle that's put through your skin and into
the tumor. The needle is guided into the tumor using CT scans or ultrasound. Then
a tiny bit of the tumor is pulled into the needle.
A healthcare provider called a pathologist runs tests on the biopsy samples in a lab
and looks at them with a microscope.
A biopsy may not be done if the healthcare provider can be sure it's bile duct cancer
based on imaging tests. Or it may not be done if the cancer is in a place that would
be very hard to reach to do the biopsy. In these cases, surgery may be done to remove
the tumor. Cancer can then be confirmed by testing the tissue taken out during surgery.
Blood tests
Blood tests are used to learn more about your overall health and to check the following:
Liver function
Liver function tests are blood tests that show how well your liver is working. They
can't tell if you have cancer. Bile duct cancer can affect the liver. The best liver
function tests to check for cancer are bilirubin, prothrombin time (international
normalized ration, or INR), and albumin. A high level of bilirubin in your blood can
be a sign that there's 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 liver enzymes. The amount in your
blood can be measured 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
These tests look for increases in certain substances called tumor markers. Some cancers
make these substances. If you might have bile duct cancer, the markers carcinoembryonic
antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) may be checked. If these 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 healthcare provider
may repeat this test during treatment to see how well it's working.
Imaging tests
Ultrasound
This test is often the first one done. It uses sound waves to look for problems in
the bile ducts. This is done with a wand-like instrument that's pressed on the skin
over your belly. Sound waves are sent out from the wand. They bounce off your insides
and send back signals. A computer uses the signals to make images of the inside of
your body. This test is very good at showing growths inside the body and learning
more about them. For instance, it can show if a mass is a fluid-filled sac (cyst),
which means it’s probably not cancer. If it’s a solid tumor, it's more likely to be
cancer. Ultrasound can show enlarged bile ducts and some tumors.
Endoscopic or laparoscopic ultrasound
Your healthcare provider may do an endoscopic ultrasound. This test uses a thin, lighted
tube called an endoscope. It has a small ultrasound device on the end that sends out
the sound waves. The endoscope can be put in through your mouth and into your stomach
near the bile ducts.
A laparoscopic ultrasound requires surgery to make a small cut in your side. A long,
thin tool called a laparoscope is used to look inside your belly (abdomen). An ultrasound
device on the end of the laparoscope is used to make images.
Both procedures allow the healthcare provider to get closer to the bile ducts to use
ultrasound. This helps get more detailed images than a regular ultrasound. These methods
can also be used to take out tissue for a biopsy or look for swollen lymph nodes.
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 (see below), it doesn’t use an
endoscope or contrast dye. This test has fewer risks than ERCP, so healthcare providers
often use it if the only purpose is to get images of the bile ducts. MRCP can’t be
used to get biopsy samples or to place stents. Stents are tiny tubes that can be put
in the ducts to keep them open.
Endoscopic retrograde cholangiopancreatography (ERCP)
This test is one of the best ways to find bile duct cancer that's close to the pancreas.
Medicines are used to put you into a light sleep during this test. The healthcare
provider then passes a flexible tube called an endoscope down your throat, through
your stomach, and into your small intestine. The scope is used to put dye in the common
bile duct. The dye shows up on X-rays. It can help show blockages or narrowing of
the ducts.
The scope can also be used to take out tissue for a biopsy. The healthcare provider
puts a small brush with a long, flexible handle through the endoscope. The brush is
then used to scrape cells and small bits of tissue. During an ERCP, the healthcare
provider may also put in small tubes called stents to reopen a duct that's blocked
by cancer.
Percutaneous transhepatic cholangiography (PTC)
The healthcare provider may do PTC if the blockage can't be reached during ERCP. It’s
a more invasive procedure, but PTC gives a better picture of the bile ducts. It's
also very useful if the bile duct cancer is close to or inside the liver. It can show
exactly where the tumor is and how big it is. It can also help your healthcare provider
see if the tumor can be removed by surgery. Medicines are used to make you sleep and
not feel pain during PTC.
To do this test, a needle is put through your skin and into your liver so dye can
be injected into your bile duct system. The dye can be seen on X-rays, which can show
any changes or blockages in your bile ducts. During PTC, your healthcare provider
can also take a biopsy or put in a thin tube to bypass the bile blockage and allow
the bile to flow into a bag outside of your body. This is called percutaneous transhepatic
bile drainage (PTBD).
Getting your test results
When your healthcare provider has the results of your tests, your provider will contact
you. Your provider will talk with you about other tests you may need if bile duct
cancer is found. Make sure you understand your test results and what your next steps
should be.