Liver cancer is cancer that begins in the cells of your liver. Your liver is a football-sized organ that sits in the upper right portion of your abdomen, beneath your diaphragm, and above your stomach. Several types of cancer can form in the liver. The most common type of liver cancer is hepatocellular carcinoma, which begins in the main type of liver cell. Other types of liver cancer, such as intrahepatic cholangiocarcinoma and hepatoblastoma, are much less common.