Tumors of the Bile Ducts and Gallbladder
Bile is a fluid that is produced by the liver and aids in digestion. Bile is transported through small tubes (bile ducts) that carry bile through the liver and then from the liver to the gallbladder and to the small intestine. The gallbladder is a small, pear-shaped sac located beneath the liver that stores bile and releases it when needed. (See also Overview of Gallbladder and Bile Duct Disorders.)
Cancer of the bile ducts (cholangiocarcinoma) is rare. It can originate anywhere in the bile ducts, particularly in those outside of the liver. Being older or having primary sclerosing cholangitis increases the risk of developing this cancer.
Cancer of the gallbladder is also rare. Nearly everyone with gallbladder cancer has gallstones. Many people live only a few months after this cancer develops. This cancer is more common among American Indians, people with large gallstones, and people with a extensive scarring of the gallbladder, which can occur in severe chronic cholecystitis.
Polyps, which are noncancerous (benign) outgrowths of tissue, may develop in the gallbladder. They rarely cause symptoms or require treatment. They are found in about 5% of people during ultrasonography.
Sometimes cancers can block the flow of bile, but most blockages are caused by gallstones. Even less often, cancer can spread (metastasize) from elsewhere in the body to adjacent structures or nearby lymph nodes, causing blockage. Noncancerous tumors in bile ducts also cause blockages.
Early symptoms include the following:
Worsening jaundice (yellowish discoloration of the skin and whites of the eyes)
Loss of appetite
Symptoms gradually worsen. Abdominal pain may become increasingly severe and constant. The pain is usually caused by blockage of the bile ducts. The stool may become pale. People feel tired and uncomfortable. They may feel a mass in their abdomen.
Gallbladder cancer causes similar symptoms.
Most gallbladder polyps cause no symptoms.
Doctors suspect bile duct or gallbladder cancer when a bile duct is blocked and no other cause is identified. Bile duct cancer is suspected especially in people with primary sclerosing cholangitis (PSC). If people have PSC, blood tests to measure substances secreted by tumors (tumor markers) are done periodically to check for this cancer.
The diagnosis is confirmed by imaging tests. Usually, ultrasonography is done first. Sometimes computed tomography (CT) is done, but results are often not conclusive. CT cholangiography (CT of the bile ducts done after a radiopaque contrast agent is injected into a vein) or magnetic resonance cholangiopancreatography (MRCP) is usually necessary.
If results of imaging tests are unclear, endoscopic retrograde cholangiopancreatography (ERCP) is done. In this procedure, a flexible viewing tube (endoscope) is inserted through the mouth and into the small intestine. A thin tube (catheter) is inserted through the endoscope, and a radiopaque contrast agent, which is visible on x-rays, is injected through the catheter into the bile ducts. Then x-rays are taken to detect any abnormalities. This procedure enables doctors to obtain images and a tissue sample for examination under a microscope (see Figure: Understanding Endoscopic Retrograde Cholangiopancreatography).
If these tests suggest a tumor but are not conclusive, doctors take a tissue sample by inserting a thin needle through the skin into the area thought to be abnormal. Ultrasonography or CT is used to guide the needle.
To determine how extensive the cancer is, doctors may have to do surgery to directly examine the area (a procedure called a diagnostic laparoscopy or an open laparotomy).
Most bile duct and gallbladder cancers are fatal, but treatment can help control symptoms.
Tubes (stents) inserted into a duct allow bile to flow past the blockage. This procedure helps control pain and relieves itchiness. Stents can be inserted during ERCP.
Surgery to remove a cancerous tumor may be done, but usually the tumor cannot be completely removed. Chemotherapy and radiation therapy for cholangiocarcinoma are being studied. If tumors have spread from other parts of the body (metastasized), chemotherapy may provide some symptom relief but does not dramatically improve survival.
Very early gallbladder cancer that is found during surgery for gallstones can often be cured by removing the gallbladder.
If bile duct cancer is limited to the bottom of the liver (where the bile ducts outside of the liver meet the bile ducts inside the liver), a liver transplant may be a curative option.