Gallbladder cancer is most often discovered incidentally, through surgical removal of the gallbladder to treat gallstones or other conditions. Because bile duct cancer does not cause any symptoms initially, it is usually not diagnosed until a patient becomes jaundiced, but may be found if abnormal liver function tests are discovered. Occasionally bile duct cancer will be identified incidentally on a CT scan performed for another reason.
Blood tests, diagnostic imaging, biopsy, or a combination of these methods may be used to make an accurate diagnosis and stage gallbladder and bile duct cancer.
Diagnosing gallbladder and bile duct cancer may begin with a test to measure the amount of bilirubin, a chemical that gives bile its yellow color, in the blood. An elevated bilirubin level, which leads to jaundice, may indicate problems with the gallbladder or liver. Another blood test measures levels of an enzyme called alkaline phosphatase, which increases when even a small portion of the bile ducts are blocked. Additional blood tests can identify abnormal amounts of other substances, including the tumor markers (proteins found in the blood when certain cancers are present) CEA and CA 19-9.
Our doctors use the latest imaging techniques to pinpoint the exact size and location of newly diagnosed gallbladder and bile duct tumors. These details help doctors determine whether a tumor can be surgically removed and predict its response to treatment. Imaging also helps guide surgeons and interventional radiologists during a variety of therapeutic procedures.
Here are some of the imaging techniques commonly used in gallbladder and bile duct cancer:
- Triphasic CT
Doctors first determine the extent of the disease with triphasic CT scanning, a method of diagnosing and staging gallbladder and bile duct cancer. Triphasic CT provides images of the liver, bile ducts, and nearby lymph nodes during three different phases of blood flow through the liver.
- Magnetic Resonance Cholangiopancreatography (MRCP)
This technique, which reveals the extent of tumor growth within the gallbladder or bile ducts, helps doctors determine if a tumor can be surgically removed. More detailed MRI may be needed to see if the tumor has spread to the liver or other organs.
This is useful for detecting the location and number of tumors, and whether the tumor involves the main blood vessels. (Tumors located near blood vessels may be more difficult to remove). Ultrasound also can be used to distinguish a cancerous mass from benign (noncancerous) gallstone disease. Unlike CT and MRI, ultrasound does not use radiation.
- Positron Emission Tomography (PET)
PET scans are especially useful in identifying metastases (tumors that have spread from the gallbladder or bile ducts to other tissues or organs). PET and CT scans can be used in combination to pinpoint the exact location of tumors.
Other Diagnostic Techniques
Additional diagnostic procedures, usually performed in an outpatient setting, may be required to gain more information about the extent of the tumor and the types of cells involved:
A small tissue sample may be obtained for microscopic examination through a technique called fine-needle aspiration (the removal of tissue or fluid for examination under a microscope). This image-guided procedure is usually performed by an interventional radiologist.
This technique, performed by a gastroenterologist, involves inserting an endoscope — a long, narrow tube attached to a camera and light — through the mouth and into the stomach to examine the interior lining of a body cavity, such as the esophagus, stomach, or colon. Endoscopy also allows doctors to examine the bile ducts, to determine if the tumor began there and to obtain a biopsy.
A surgeon passes a laparoscope — a thin, lighted tube with a camera on its tip — through the abdominal wall through a small incision to view the liver and surrounding organs, and remove tissue samples for biopsy. Laparoscopy can be used to avoid the need for exploratory surgery in some patients.
Sometimes a gallbladder or bile duct tumor is too small for a biopsy to be obtained, although other diagnostic evidence suggests the tumor may be cancerous. In these situations, the tumor may be surgically removed to confirm the diagnosis and offer a potential cure without a preoperative tissue diagnosis of cancer. For more information about surgery, visit the Treatment section.