Cancer is when cells in your body change and grow out of control. Your body is made up of tiny building blocks called cells. Normal cells grow when your body needs them, and die when your body does not need them any longer.

Cancer is made up of abnormal cells that grow even though your body doesn’t need them. In most cancers, the abnormal cells grow to form a lump or mass called a tumor. If cancer cells are in the body long enough, they can grow into (invade) nearby areas. They can even spread to other parts of the body (metastasis).

Gallbladder cancer is when cancer starts in cells that make up the gallbladder. It’s not a common cancer.                                                                                                                      

The gallbladder is a small organ that sits just below your liver, under your ribs on the right upper side of your belly. It stores liquid called bile that’s made by the liver. Bile is part of the process of digestion. It helps break down the fat in foods you eat. The gallbladder releases bile through a series of ducts that connect to the first part of your small intestine (duodenum).

Gallbladder cancer can be one of several different types, including:

• Adenocarcinoma. This is the most common type of gallbladder cancer. About 90% of people with gallbladder cancer have this type. It starts in gland cells.

• Other types. About 10% of people with gallbladder cancer have other types. These include squamous cell carcinoma, adenosquamous carcinoma, small cell carcinoma, and sarcoma. These types are not common.

Gallbladder cancer doesn’t cause symptoms in its early stages (when it's small and hasn't spread). But it is sometimes found early when an imaging test is done to look for gallstones. Gallstones are lumps of crystal deposits that can form in the gallbladder. Gallstones may cause pain and other symptoms. In some cases, cancer may not be found until the gallbladder is removed because of gallstones.

Over time, gallbladder cancer can spread. The cancer cells can grow in the liver and in nearby lymph nodes. It can also spread to other organs far away from the gallbladder. Gallbladder cancer is harder to treat once it has spread.

If you have questions about gallbladder cancer, talk with your healthcare provider. He or she can help you understand more about this cancer.