This is a medical question of type : exams and tests 
 How to diagnose Bile Duct Cancer (Cholangiocarcinoma) ? 
 Tests that examine the bile ducts and nearby organs are used to detect (find), diagnose, and stage bile duct cancer. Procedures that make pictures of the bile ducts and the nearby area help diagnose bile duct cancer and show how far the cancer has spread. The process used to find out if cancer cells have spread within and around the bile ducts or to distant parts of the body is called staging.    In order to plan treatment, it is important to know if the bile duct cancer can be removed by surgery. Tests and procedures to detect, diagnose, and stage bile duct cancer are usually done at the same time.   The following tests and procedures may be used:         -   Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patients health habits and past illnesses and treatments will also be taken.    -   Liver function tests : A procedure in which a blood sample is checked to measure the amounts of bilirubin and alkaline phosphatase released into the blood by the liver. A higher than normal amount of these substances can be a sign of liver disease that may be caused by bile duct cancer.    -   Laboratory tests : Medical procedures that test samples of tissue, blood, urine, or other substances in the body. These tests help to diagnose disease, plan and check treatment, or monitor the disease over time.    -   Carcinoembryonic antigen (CEA) and CA 19-9 tumor marker test : A procedure in which a sample of blood, urine, or tissue is checked to measure the amounts of certain substances made by organs, tissues, or tumor cells in the body. Certain substances are linked to specific types of cancer when found in increased levels in the body. These are called tumor markers. Higher than normal levels of carcinoembryonic antigen (CEA) and CA 19-9 may mean there is bile duct cancer.    -   Ultrasound exam : A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs, such as the abdomen, and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.    -   CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the abdomen, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.    -   MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).    -  MRCP (magnetic resonance cholangiopancreatography): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body such as the liver, bile ducts, gallbladder, pancreas, and pancreatic duct.
                    Different procedures may be used to obtain a sample of tissue and diagnose bile duct cancer. Cells and tissues are removed during a biopsy so they can be viewed under a microscope by a pathologist to check for signs of cancer. Different procedures may be used to obtain the sample of cells and tissue. The type of procedure used depends on whether the patient is well enough to have surgery.    Types of biopsy procedures include the following:         -   Laparoscopy : A surgical procedure to look at the organs inside the abdomen, such as the bile ducts and liver, to check for signs of cancer. Small incisions (cuts) are made in the wall of the abdomen and a laparoscope (a thin, lighted tube) is inserted into one of the incisions. Other instruments may be inserted through the same or other incisions to perform procedures such as taking tissue samples to be checked for signs of cancer.    -   Percutaneous transhepatic cholangiography (PTC): A procedure used to x-ray the liver and bile ducts. A thin needle is inserted through the skin below the ribs and into the liver. Dye is injected into the liver or bile ducts and an x-ray is taken. A sample of tissue is removed and checked for signs of cancer. If the bile duct is blocked, a thin, flexible tube called a stent may be left in the liver to drain bile into the small intestine or a collection bag outside the body. This procedure may be used when a patient cannot have surgery.    -   Endoscopic retrograde cholangiopancreatography (ERCP): A procedure used to x-ray the ducts (tubes) that carry bile from the liver to the gallbladder and from the gallbladder to the small intestine. Sometimes bile duct cancer causes these ducts to narrow and block or slow the flow of bile, causing jaundice. An endoscope is passed through the mouth and stomach and into the small intestine. Dye is injected through the endoscope (thin, tube-like instrument with a light and a lens for viewing) into the bile ducts and an x-ray is taken. A sample of tissue is removed and checked for signs of cancer. If the bile duct is blocked, a thin tube may be inserted into the duct to unblock it. This tube (or stent) may be left in place to keep the duct open. This procedure may be used when a patient cannot have surgery.