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?
Gallbladder cancer

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.