Hepatoma or hepatocellular carcinoma originates from cells called hepatocytes that perform majority of the liver function. It accounts for 75% of all primary liver cancers. It can occur a single tumor and can spread to other parts of the liver or multiple tumors can occur in the liver at the same time.
Cholangiomas originates from the cells that line the bile ducts of the liver and accounts for 10 to 20% of all primary liver cancers. The bile duct carries the bile, produced by the liver to the gall bladder. Inflammation of the bowel and parasitic infection of the liver (liver fluke) is believed to cause this type of cancer.
Secondary liver cancer originates in some other region of the body such as the colon, stomach, lung or breast and spreads to the liver. In addition, liver cancer cells can spread to other parts of the body such as the bones or lungs. This phenomenon of spread of the tumor from one region to the other is called metastasis.