Liver cancer refers to tumors that occur in the liver and are classified as benign or malignant. Benign tumors of the liver are rare. Those of epithelial origin include: hepatocellular adenoma, adenomatous hyperplasia, biliary adenoma, biliary cystic adenoma, and microscopic malformation tumor. Those originating from the mesoderm include: cavernous hemangioma and hemangioendothelioma of young children. Mixed tumors include teratomas. Congenital liver cysts are also benign tumors. Malignant tumors of the liver are mainly primary and secondary hepatocellular carcinoma. Primary liver cancer mainly includes types such as hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC) and mixed hepatocellular carcinoma-intrahepatic cholangiocarcinoma; what we call liver cancer generally refers to primary hepatocellular carcinoma (HCC). Secondary liver cancer mainly refers to malignant tumors that metastasize or invade the liver from other parts of the body, so it is also called metastatic liver cancer.