A. The liver is the largest internal organ of the body. It is located on the right side of the abdomen, beneath the right lung, and is protected by the lower ribcage. The liver performs many functions that are necessary for survival. Several types of tumors, both benign (non-cancerous) and malignant (cancerous) can develop in the liver. The most common type of liver cancer is hepatocellular carcinoma (HCC). It accounts for 84 percent of primary liver cancers (cancer that originates in the liver). The liver can also develop metastatic or secondary tumors. These tumors have spread from cancer in another part of the body, like the breast, colon or pancreas. This is not called "liver cancer"; it is instead named for the part of the body where the cancer originated (e.g., metastatic breast cancer). In the United States, metastatic liver tumors are more common than primary liver cancer.