Diagnosis of Cholangiocarcinoma Overview
Diagnosis of Cholangiocarcinoma Overview
Most bile duct cancers are not found until patients go to a doctor because they have symptoms. The bile ducts are deep inside the body, so early tumors can’t be seen or felt during routine physical exams. There are no blood tests or other tests that can reliably detect bile duct cancers early enough to be useful as screening tests (Screening is testing for cancer in people without any symptoms.). Because of this, most bile duct cancers are found only after the cancer has grown enough to cause signs or symptoms.
Diagnosis of Cholangiocarcinoma may include the following:
History and physical exam:
If there is reason to suspect that you might have bile duct cancer, your doctor will want to take a complete medical history to check for risk factors and to learn more about your symptoms.
A physical exam is done to look for signs of bile duct cancer or other health problems. If symptoms and/or the results of the physical exam suggest you might have bile duct cancer, other tests will be done. These could include lab tests, imaging tests, and other procedures.
Tests of liver and gallbladder function:
The doctor may order lab tests to find out how much bilirubin is in the blood, for albumin, for liver enzymes (alkaline phosphatase, AST, ALT, and GGT), and certain other substances in your blood. These tests can indicate bile duct, gallbladder, or liver disease. If levels of these substances are higher, it might point to blockage of the bile duct, but they can’t show if it is due to cancer or some other reason.
Tumor markers are substances made by cancer cells that can sometimes be found in the blood. People with bile duct cancer may have high blood levels of the CEA and CA 19-9 tumor markers. High amounts of these substances often mean that cancer is present. These tests can sometimes be useful after a person is diagnosed with bile duct cancer. If the levels of these markers are found to be high, they can be followed over time to help tell how well treatment is working.
For this test, a small, microphone-like instrument called a transducer gives off sound waves and picks up their echoes as they bounce off organs inside the body. The echoes are converted by a computer into an image on a screen.
This is a totally painless, non-invasive procedure. The test does not require special preparation, although it is technically easier in patients with at least six hours of fasting. Abdominal ultrasound is usually recommended as the first imaging test for the investigation of patients with suspected cholangiocarcinoma. In some cases, abdominal ultrasound can allow the tumor itself to be visualized as a rounded mass. Abdominal ultrasound can also detect the presence of liver metastases as single or multiple rounded lesions in different return signals from the ultrasound.
Computed tomography (CT) scan:
The CT scan uses x-rays to make detailed cross-sectional images of your body. Instead of taking one x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these images into slices of the part of your body that is being studied.
CT scans can have several uses:
▪ They often help diagnose bile duct cancer by showing tumors in the area.
▪ They can help stage the cancer (find out how far it has spread). CT scans can show the organs near the bile duct (especially the liver), as well as lymph nodes and distant organs where cancer might have spread to.
▪ CT scans can also be used to guide a biopsy needle into a suspected tumor or metastasis.
Magnetic resonance imaging (MRI) scan:
Like CT scans, MRI scans provide detailed images of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. A contrast material called gadolinium may be injected into a vein before the scan to better see details. MRI scans provide a great deal of detail and can be very helpful in looking at the bile ducts and nearby organs. Sometimes they can help tell a benign tumor from a cancerous one. MRI scans can be a little more uncomfortable than CT scans. They take longer, often up to an hour. You may have to lie inside a narrow tube, which is confining and can upset people with a fear of enclosed spaces. Special, more open MRI machines can sometimes be used instead.
A cholangiogram is an imaging test that looks at the bile ducts to see if they are blocked, narrowed, or dilated (widened). This can help show if someone might have a tumor that is blocking a duct. It can also be used to help plan surgery. There are several types of cholangiograms, which have different pros and cons.
Magnetic resonance cholangiopancreatography (MRCP):
This is a non-invasive way to image the bile ducts using the same type of machine used for standard MRI scans. Because it is non-invasive, doctors often use MRCP if the purpose of the test is just to image the bile ducts.
▪ Endoscopic retrograde cholangiopancreatography (ERCP):
In this procedure, a doctor passes a long, flexible tube (endoscope) down the throat, through the esophagus and stomach, and into the first part of the small intestine. This is usually done while you are sedated (given medicine to make you sleepy). A small catheter (tube) is passed from the end of the endoscope and into the common bile duct. A small amount of contrast dye is injected through the tube to help outline the bile ducts and pancreatic duct as x-rays are taken. The images can show narrowing or blockage of these ducts. This approach can also be used to take samples of fluid or tissues durring the procedure.
▪ Percutaneous transhepatic cholangiography (PTC):
In this procedure, the doctor places a thin, hollow needle through the skin of the belly and into a bile duct within the liver. You will get medicine through an IV line to make you sleepy before the test. A local anesthetic is also used to numb the area before inserting the needle. A contrast dye is then injected through the needle, and x-rays are taken as it passes through the bile ducts. Like ERCP, this approach can also be used to take samples of fluid or tissues. Because it is more invasive (and might cause more pain), PTC is not usually used unless ERCP has already been tried or can’t be done for some reason.
Laparoscopy is a type of minor surgery. The doctor inserts a thin tube with a light and a small video camera on the end (a laparoscope) through a small cut in the front of the abdomen to look at the bile duct, gallbladder, liver, and other organs and tissues in the area. This procedure is typically done in the operating room while you are under general anesthesia (in a deep sleep).
Laparoscopy can help doctors plan surgery or other treatments, and can help assess the stage (extent) of the cancer. If needed, doctors can also insert instruments through the incisions to remove small biopsy samples to be looked at under a microscope. This procedure is often done before surgery to remove the cancer, to help make sure the tumor can be removed completely.
This procedure can be done during an ERCP (see above). The doctor passes a very thin fiber-optic tube with a tiny camera on the end down through the larger tube used for the ERCP. From there it can be maneuvered into the bile ducts. This lets the doctor see any blockages, stones, or tumors and even biopsy them.
Imaging tests (ultrasound, CT or MRI scans, cholangiography, etc.) might suggest that a bile duct cancer is present, but in many cases a sample of bile duct cells or tissue is removed (biopsied) and looked at under a microscope to be sure of the diagnosis.There are several ways to take biopsy samples to diagnose bile duct cancer.
Types of biopsies:
▪ During cholangiography:
If ERCP or PTC is being done, a sample of bile may be collected during the procedure to look for tumor cells within the fluid.
Bile duct cells and tiny fragments of bile duct tissue can also be sampled during cholangiography by biliary brushing. The doctor advances a small brush with a long, flexible handle through the endoscope or needle. The end of the brush is used to scrape cells and small tissue fragments from the lining of the bile duct, which are then looked at under a microscope.
▪ Needle biopsy:
For this test, a thin, hollow needle is inserted through the skin and into the tumor without first making a surgical incision. (The skin is numbed first with a local anesthetic.) The needle is usually guided into place using ultrasound or CT scans. When the images show that the needle is in the tumor, a sample is drawn into the needle and sent to the lab to be viewed under a microscope.
In most cases, this is done as a fine needle aspiration (FNA) biopsy, which uses a very thin needle attached to a syringe to suck out (aspirate) a sample of cells. Sometimes, the FNA doesn’t provide enough cells for a definite diagnosis, so a core needle biopsy may be done, which uses a slightly larger needle to get a bigger sample.