Understanding the Gallbladder and the Bile Ducts
The gallbladder is a small pear-shaped organ located just below the liver. Its main function is to store, concentrate and ensure release of bile (a fluid produced by the liver that aids in the digestion of fats) whenever required. The gallbladder contracts and releases bile into the small intestine during digestion. There are three layers in the wall of gallbladder.
- The mucosal (inner) layer
- The muscularis (middle) layer
- The serosal (outer) layer
There are several bile ducts present within the liver that carry bile which join together to form one main bile duct, in which the gallbladder drains via a duct called as cystic duct.
What is Gallbladder and Bile Duct Cancer
Gallbladder cancer usually begins in the innermost of the three layers and grows outwards as it spreads.
Bile duct cancer (also known as Cholangiocarcinoma) is a rare type of cancer that can start anywhere along the bile ducts and can cause blockage.
Although gallbladder and bile duct cancers are different cancer types, we frequently discuss them together because diagnosis and treatment for each type are similar.
What are the types of Gallbladder and Bile Duct cancers?
Most primary gallbladder and bile duct cancers are adenocarcinomas. These are the growths that begin in the mucus glands that line the insides of the gallbladder and bile ducts.
Tumors of bile duct can occur in the main bile duct outside the liver (extrahepatic) or within the liver (intrahepatic).
How common are these cancers?
It is more common in India (Patna) and some Asian countries.
According to the 2018 statistics, the number of new cases diagnosed with gallbladder cancer was 25,999 and the total number of deaths due to the same was 19,676.
It is more common in females. The male to female ratio is 1:3.
Bile Duct cancer
This is a highly rare type of cancer. However, it is more common in India as compared to western countries.
What are the risk factors for Gallbladder and Bile Duct cancers?
- Gallstones and Inflammation
Gallstones are hard, rock-like formations made of cholesterol and other substances in the gallbladder and are the biggest risk factor for gallbladder cancer. Up to 90 percent of people diagnosed with gallbladder cancer also have gallstones and chronic inflammation of the gallbladder. People with larger gallstones (3 centimeters) are ten times more likely to develop gallbladder cancer than those with small stones (1 centimeter).
- Porcelain Gallbladder
This is a condition in which the gallbladder becomes covered in calcium deposits, resembling porcelain ceramic.
People who are chronically, or persistently, infected with salmonella (the bacterium that causes typhoid) are six times more likely to develop gallbladder cancer than those who are not infected.
Many patients with gallbladder cancer are overweight or obese and have a high-carbohydrate or low-fiber diet.
- Family History
Gallbladder cancer sometimes runs in families.
- Gallbladder Polyps
Gallbladder polyps are growths that protrude from the gallbladder’s mucous membrane. These polyps are usually symptomless. Some polyps are precancerous and can progress to cancer. Polyps that are 1 centimeter or larger, appear to be growing, or have a broad base should be removed to prevent cancer.
Bile Duct Cancer
- Ulcerative Colitis
Ulcerative colitis is an inflammation of the large intestine that is often associated with inflammation of the bile duct (a condition known as sclerosing cholangitis). Ulcerative colitis can progress to cancer, particularly in people exposed to other carcinogens such as cigarette smoke.
- Biliary Parasites
Food or water-borne parasites that reside in the bile ducts are common in Asia and raise the risk of developing bile duct cancer.
- Congenital Bile Duct Cysts (Choledochal Cysts)
These bile-filled sacs are connected to the common bile duct. Congenital bile duct cysts are typically diagnosed in childhood. The lining of these sacs often contains precancerous cells that increase the risk of developing cancer later in life.
- Chronic Hepatitis C
This inflammatory disease is the most common risk factor for liver cancer and also is considered a risk factor for cancer of the intrahepatic bile ducts.
A recent study suggests that intrahepatic bile duct cancer is more common among heavy smokers.
This condition appears to be an increasingly important risk factor for intrahepatic bile duct cancer.
- Presence of gall stones in the bile ducts of the liver
- Lynch Syndrome II
What are the symptoms of Gallbladder and Bile Duct cancers?
- Pain is usually seen in the right upper quadrant of the abdomen
- Mass in right upper abdomen which is hard and painless
- Jaundice may be present
- Significant weight loss in a short duration; loss of appetite
- There might be acute presentation of Cholecystitis (inflammation of gallbladder)
- This type of cancer can also have an atypical presentation with unusual features
Bile Duct cancer
- Main presentation is jaundice without fever of short duration
- Weight loss and loss of appetite is typical and significant
- Itchy skin
- White, chalky colour stools
- Dark yellow coloured urine
- Vague pain in the right upper quadrant of abdomen due to liver enlargement
- Sometimes black tarry stools may be seen
How are Gallbladder and Bile Duct cancers diagnosed?
- Ultrasound of abdomen
- CT Scan of abdomen
- Fine needle aspiration cytology (FNAC)
- Tumour marker tests for CEA and CA 19-9
- Liver Function Tests
- Magnetic resonance cholangiopancreatography(MRCP) is a technique for viewing the bile ducts and the pancreatic duct with the help of MRI based principle. It can also show the pancreas, gallbladder and liver.
- Diagnostic laparoscopy
Bile Duct Cancer
- Ultrasound of abdomen
- CT scan of abdomen
- Liver Function tests
- Magnetic Resonance (MR) Scan
- Endoscopic Retrograde Cholangiopancreatography (ERCP): This x-ray of the bile ducts can reveal whether bile duct cancer has narrowed or blocked the ducts. A thin, lighted tube (endoscope) is passed through the mouth, esophagus, and stomach into the first part of the small intestine. A smaller tube (catheter) inserted through the endoscope into the bile ducts, delivers dye to the ducts and an x-ray is taken. If ducts are blocked, a fine tube may be inserted to unblock the duct, or placed (as a stent) to keep the duct open. Tissue biopsy may be done during this procedure.
- Percutaneous Transhepatic Cholangiography (PTC): A thin needle inserted through the skin below the ribs injects dye into the liver, and an x-ray is taken. If a blockage is found, a stent in the liver can drain bile into the small intestine or a collection bag outside the body.
How are Gallbladder and Bile Duct cancers treated?
For both gallbladder and bile duct cancers, treatment options typically include the following, which can be given in combination, depending upon the stage:
- Surgery: In early stages the gallbladder with surrounding some part of liver and lymph nodes is removed (Radical Cholecystectomy). For early stages of lower bile duct cancers, a Whipple’s procedure is done.
- Chemotherapy and Radiation Therapy: Usually given in later stages where surgery cannot be performed. Chemotherapy can be given after surgery also.
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