ON THIS PAGE: You will find some basic information about this disease and the parts of the body it may affect. This is the first page of Cancer.Net’s Guide to Gallbladder Cancer. To see other pages, use the menu on the side of your screen. Think of that menu as a roadmap to this full guide.
Gallbladder cancer occurs when healthy cells in the gallbladder change and grow uncontrollably, forming a mass called a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can spread to other parts of the body. A benign tumor means the tumor will not spread. This section is about primary gallbladder cancer. Primary gallbladder cancer is cancer that starts in the gallbladder, as opposed to cancer that begins somewhere else in the body and spreads to the gallbladder.
About the gallbladder
The gallbladder is a pear-shaped organ located just under the liver. The gallbladder stores bile, a fluid made by the liver that helps to digest fats. Bile is released from the gallbladder through a tube, called the common bile duct, as food is broken down in the stomach and intestines.
The gallbladder’s wall is made up of three main layers of tissue
the mucosa, which is the innermost layer and covers the wall of the gallbladder
the muscularis, the middle layer of smooth muscle
the serosa, the outer layer
Primary gallbladder cancer begins in the inner layer and spreads into the outer layers as it grows.
Looking for More of an Overview?
If you would like additional introductory information, explore this related item. Please note this link will take you to another section on Cancer.Net:
- Cancer.Net En Español : Read about gallbladder cancer in Spanish. Infórmase sobre cáncer de vesícula biliar en español. 
The next section in this guide is Statistics  and it helps explain how many people are diagnosed with this disease and general survival rates. Or, use the menu on the side of your screen to choose another section to continue reading this guide.