Gallbladder cancer is a rare type of cancer that starts in the tissues of the gallbladder.
Gallbladder cancer occurs when cells in the gallbladder start to grow out of control. The gallbladder is a pear-shaped organ that lies just under the liver in the upper abdomen. The gallbladder stores bile, a fluid made by the liver to digest fat. When food is being broken down in the stomach and intestines, bile is released from the gallbladder through a tube called the common bile duct, which connects the gallbladder and liver to the first part of the small intestine.