It can be difficult to diagnose bile duct cancer. You may need to have a number of different tests.
Some of the tests that may be carried out are described below.
In bile duct cancer, the cancerous cells may release certain chemicals that can be detected using blood tests. These are known as tumour markers.
But tumour markers can also be caused by other conditions, so this test can't be used to say for certain whether or not you have bile duct cancer.
Several scans can be used to examine your bile ducts in detail and to check for lumps or other abnormalities that could be the result of cancer.
Endoscopic retrograde cholangio-pancreatography (ERCP) allows your bile ducts to be seen clearly on an X-ray scanner.
During the test:
You'll be awake while the test is carried out, but you'll normally be given an injection of sedative medication to make you very drowsy and your throat will be numbed with local anaesthetic spray.
Percutaneous transhepatic cholangiography (PTC) may also be used to get a detailed image of your bile duct.
During the test:
You'll be awake while this is carried out, but you'll usually have sedative medication to make you drowsy and local anaesthetic to numb the area where the needle is inserted.
If you're diagnosed with bile duct cancer, it will be possible to give your cancer a "stage". This is a number that indicates how far the cancer has spread.
Doctors use a system called the TNM system to stage bile duct cancer. This consists of three numbers:
Knowing the stage of your cancer will help your doctors decide on the best treatment for you.
Cancer Research UK has more detailed information about the stages of bile duct cancer.