ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. Use the menu to see other pages.
Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If this happens, it is called metastasis. For example, imaging tests can show if the cancer has spread. Imaging tests show pictures of the inside of the body. Doctors may also do tests to learn which treatments could work best.
For most types of cancer, a biopsy is the only sure way for the doctor to know if an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.
This section describes options for diagnosing bile duct cancer. Not all tests listed below will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:
The type of cancer suspected
Your signs and symptoms
Your age and general health
The results of earlier medical tests
In addition to a physical examination, the following lab tests may be used to diagnose bile duct cancer or identify it as the cause of jaundice (see Symptoms and Signs):
Blood chemistry tests. Blood chemistry tests measure the levels of bilirubin and alkaline phosphatase and check other liver functions. High levels of these substances could indicate that the bile duct is not working well.
Tumor marker tests (CEA and CA19-9). Tumor marker tests look for higher-than-normal amounts of certain substances in the blood, urine, or tissues of people with certain types of cancer. Bile duct cancer may cause high levels of carcinoembryonic antigen (CEA) and CA19-9 in the blood. However, a person can have bile duct cancer even if there are normal levels of these tumor markers. Also, there are diseases other than cancer that sometimes cause high levels of these substances.
Other tests may be performed to provide more information about the bile duct cancer. These include:
- Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. A pathologist then analyzes the sample(s). A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease.
The type of biopsy performed depends on the location of the tumor. The doctor can remove tissue samples during a procedure called a percutaneous transhepatic cholangiography (PTC), which is now rarely used, or another procedure called an endoscopic retrograde cholangiopancreatography (ERCP). PTC and ERCP are described below. Or, a computed tomography scan (CT or CAT scan, see below) may help guide a thin needle through the skin into the area to collect a sample of cells.
Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. Occasionally, a biopsy is not possible. In this uncommon situation, people will be treated for bile duct cancer based on other test results and symptoms.
- Ultrasound. An ultrasound uses sound waves to create a picture of the internal organs. During an ultrasound, the doctor may be able to see the actual tumor. However, more often, the ultrasound will show that the small bile ducts have become larger. This is called a “dilation of ducts.” The small bile ducts are located behind a blockage of 1 of the larger bile ducts. Ultrasound can be used to guide a needle through the skin and into the liver toward a suspected cancer to get a sample tissue for diagnosis.
To view the bile duct, the doctor may alternatively use an endoscopic ultrasound. The doctor inserts a thin, flexible tube, called an endoscope, through the mouth. An ultrasound probe is built into the endoscope. A needle can be passed through the scope to take cells from the mass.
The doctor may also perform an endoscopic retrograde cholangiopancreatography (ERCP). During an ERCP, the doctor inserts a flexible tube down a person’s throat, through the stomach, and into the bile duct. The patient is lightly sedated while this occurs. Sedation is the use of medication to become more relaxed, calm, or sleepy. Dye is injected into the tube, which helps outline the bile duct on an x-ray. A tiny brush can also be inserted through the tube to collect cells and tissue fragments for a biopsy. This technique can help find and take a sample of the tumor. It provides information that is important in planning treatment.
Less commonly, a surgeon may use a laparoscopic ultrasound (see below). Both of these procedures provide a clearer view of the bile duct. This helps the doctor perform a biopsy.
- Computed tomography (CT or CAT) scan. A CT scan takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed 3-dimensional image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow. A CT scan can also be used to guide a needle to a suspected tumor.
- Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A specialized MRI used for the bile duct is called MRI cholangiopancreatography. A contrast medium may be given before the MRI to create a clearer picture. This dye can be injected into a patient's vein or given as a pill or liquid.
- PTC. During this test, a thin needle is inserted into the bile duct in the liver. The doctor injects a contrast medium through the needle that allows the bile ducts to show up on x-rays. By looking at the x-rays, the doctor can tell whether and where there is a blockage of the bile ducts. This is important in planning treatment.
- Laparoscopy. During laparoscopy, a doctor views the bile duct, gallbladder, and liver through a lighted tube, called a laparoscope. The laparoscope is inserted into a surgical opening in the person’s abdomen. Some laparoscopes can help the doctor take a tissue sample by using small instruments through the tube.
After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer. This is called staging.
The next section in this guide is Stages. It explains the system doctors use to describe the extent of the disease. Use the menu to choose a different section to read in this guide.