Each year, liver cancer is diagnosed in approximately 21,000 people in the United States, with over 70 percent of cases affecting men, according to the National Cancer Institute. The liver removes harmful substances from the body and produces enzymes and bile that aid in the digestion of food. When a cell of the liver transforms into a cell that grows uncontrollably, the result is liver cancer, of which there are a few different types.
Hepatocellular Carcinoma
Merck Manuals, an online medical library, notes that hepatocellular carcinoma results in the deaths of 14,000 Americans each year. Hepatocellular carcinoma is the most common type of liver cancer, accounting for approximately 75 percent of liver cancer cases, according to the American Cancer Society. Two main patterns characterize hepatocellular carcinoma growth. The cancer may grow in the liver as a single tumor and only spread to other parts of the liver late in the progression of the disease. Alternatively, the cancer may grow in many different spots throughout the liver, which characterizes the second common growth pattern.
The risk of developing liver cancer increases over 100 fold when a person is infected with the hepatitis B virus, according to Merck Manuals. This virus gets into the cells of the liver and can cause them to transform into cancer cells. Other disorders that increase a person's risk of developing hepatocellular carcinoma include chronic infection with the hepatitis C virus and alcoholic liver cirrhosis.
Bile Duct Cancers
Another type of liver cancer involves transformation of the cells of the bile duct in the liver. Cancer of the liver bile duct accounts for 10 to 20 percent of all liver cancer cases, according to the American Cancer Society. This type of cancer begins in the cells of the small tubes called bile ducts, which deliver bile from the liver to the gall bladder.
Hepatoblastoma
The Children's Hospital of Pittsburgh describes hepatoblastoma as a rare cancerous tumor that grows in the livers of primarily children. Hepatoblastoma affects children between infancy and 5 years, but most commonly occurs before a child is 18 months old. Though scientists are not sure of the exact causes of hepatoblastoma, they speculate that certain genes may have a role, as well as infection with the hepatitis B virus while very young. The liver is naturally divided into two lobes: the right lobe and the left lobe. Hepatoblastoma most often begins in the right lobe, though the reason for this is as yet unknown.
