Tumors are abnormal masses of tissue that form when cells begin to reproduce at an increased rate. Both noncancerous (benign) and cancerous (malignant) tumors can develop in the liver.
What are noncancerous liver tumors?
Noncancerous tumors are known as benign. Believe it or not, they’re actually quite common and usually have no symptoms. In fact, if they’re found at all it’s because the patient has undergone an ultrasound, or a CT or MRI scan.
Benign tumors can sometimes grow large enough to cause problems, but they don’t grow into nearby tissues or spread to distant parts of the body like malignant or cancerous tumors might. If they need to be treated – and we will decide this together, based on our findings – the patient can usually be cured with surgery.
Types of benign liver tumors include:
The most common type of benign liver tumor, hemangiomas start in blood vessels. Most hemangiomas of the liver cause no symptoms and do not need treatment. But some may bleed or become so large they cause pain and may need to be removed surgically.
- Hepatic adenoma
Hepatic adenoma is a benign tumor that starts from the main type of liver cell called hepatocytes. Most cause no symptoms and do not need treatment. But some eventually cause symptoms, such as pain or a mass in the stomach or blood loss. Because there is a risk that the tumor could rupture, leading to severe blood loss, as well as a small risk that it might eventually develop into liver cancer, we may recommend surgery to remove the tumor.
- Focal nodular hyperplasia
Focal nodular hyperplasia (FNH) is a tumor-like growth made up of several cell types (hepatocytes, bile duct cells, and connective tissue cells). Although FNH tumors are benign, it can be hard to tell them apart from true liver cancers, and we often remove them when the diagnosis is unclear. If you have symptoms from an FNH tumor, it can be removed with surgery.
Both hepatic adenomas and FNH tumors are more common in women than in men and may be related to the oral contraceptive pill.
- Liver cysts
An estimated five percent of the population develops liver cysts. These cysts are benign growths that contain fluid produced by the cell wall of the cyst. Most cysts do not need therapy but some can grow and be large enough to cause pain. These can be drained laparoscopically as an outpatient.
What are cancerous liver tumors?
Cancerous or malignant liver tumors can either originate in the liver (known as primary liver cancer) or spread to the liver from another cancer elsewhere in the body (metastatic liver cancer). Most cancerous tumors in the liver are metastatic.
Types of malignant liver cancer tumors include:
- Hepatocellular carcinoma or hepatocellular cancer
Known as HCC, this is the most common form of liver cancer in adults. It is also sometimes called hepatoma. About 4 of 5 cancers that start in the liver are this type.
Hepatocellular cancer can have different growth patterns:
- Some begin as a single tumor that grows larger. Only late in the disease does it spread to other parts of the liver.
- A second type consists of a number of small cancer nodules throughout the liver, not just a single tumor. This is seen most often in people with cirrhosis (chronic liver damage).
Chronic infection with hepatitis B and C increases the risk of developing this type of cancer. In addition to cirrhosis, other causes include certain chemicals and alcoholism.
Under a microscope, we can distinguish several subtypes of HCC. Most often these subtypes do not affect treatment or the prognosis for survival. However, one of these subtypes, fibrolamellar, is important to recognize. This type is rare, making up less than one percent of HCCs. Patients with this type are usually younger than age 35, and the rest of their liver is not diseased. This subtype generally has a better outlook than other forms of HCC.
- Bile duct cancer (Intrahepatic cholangiocarcinoma)
The bile duct starts in the liver. Within the liver, smaller tubes, similar to small blood vessels, drain bile from the cells in the liver into larger and larger branches, ending in a tube called the common bile duct. Outside of the liver, the bile duct drains into the small intestine. The gallbladder is a reservoir that holds bile until food reaches the intestines. It is attached by a small duct, called the cystic duct, to the common bile duct about one-third of the way down the bile duct from the liver. The end of the bile duct empties into the small intestine.
Bile duct cancer begins when normal cells in the bile duct change and grow uncontrollably forming a mass called a tumor. A tumor can be benign or malignant.
About 10 to 20 percent of liver cancers are bile duct cancers. Surgical removal of these tumors offers the best chance for cure.
- Angiosarcoma and hemangiosarcoma
Angiosarcoma and hemangiosarcoma are both rare cancers that begin in cells lining the blood vessels of the liver. People who have been exposed to vinyl chloride or to thorium dioxide are more likely to develop these cancers. It’s also possible that exposure to arsenic or radium could lead to this type of liver cancer. And there is an inherited condition known as hemochromatosis that can also lead to these types of tumors.
These tumors grow quickly. By the time they’re found, these tumors are often too widespread to be removed surgically. Chemotherapy and radiation therapy may help slow the disease, but these cancers are usually very hard to treat.
This is a very rare kind of cancer that develops in children, usually in those younger than four years old. The cells of hepatoblastoma are similar to fetal liver cells. About two out of three children with these tumors are treated successfully with surgery and chemotherapy, although the tumors are harder to treat if they have spread outside of the liver. We don’t treat this type of cancer at Providence Saint Johns.
- Secondary or metastatic liver cancer
Most of the time when cancer is found in the liver it did not start there but has spread or metastasized from somewhere else in the body, such as the pancreas, colon, stomach, breast, or lung. These tumors are named and treated based on where they started. For example, if your cancer started in the lung and spread to the liver it’s still called lung cancer with spread to the liver, not liver cancer, and it is treated as lung cancer.
In the United States and Europe, secondary (metastatic) liver tumors are more common than primary liver cancer. The opposite is true for many areas of Asia and Africa.