Cancer that forms in tissues of the gallbladder. The gallbladder is a pear-shaped organ below the liver that collects and stores bile (a fluid made by the liver to digest fat). Gallbladder cancer begins in the innermost layer of tissue and spreads through the outer layers as it grows.
Anatomy of the gallbladder. The gallbladder is just below the liver. Bile is stored in the gallbladder and flows through the cystic duct and the common bile duct into the small intestine when food is being digested.