Depending on the cells or tissues affected, liver cancer is classified into several groups:
- Hepatocellular carcinoma – this type of cancer develops in a group of liver cells called hepatocytes. Hepatocellular carcinoma is the common type of primary liver cancer, and it is mostly due to complication of a disease already existed in the liver gland.
- Cholangiocarcinoma – also called bile duct cancer, cholangiocarcinoma develops in the ducts of the liver that carry bile to the small intestine. It can cause biliary obstruction (bile duct obstruction), hence emergence of cholestasis syndrome.
- Angiosarcoma – also known as hemangiosarcoma, angiosarcoma is a rare form of cancer that starts in blood vessels of the liver. It is often caused by prolonged exposure to toxic metals.
- Hepatoblastoma – although hepatoblastoma is a rare form of primary liver cancer, it is the most common type of liver cancer in children. It is characterized by a palpable liver mass and abdominal pain. Hepatoblastoma represents approximately 1% of all pediatric tumors with an annual incidence of 1.5 cases per million children younger than 4 years.