Liver Lesions: Top 4 Causes (& Can It Be Cancer?)

Liver lesions are often not benign in nature and not life-threatening, especially in patients who do not have a history of known liver disease. They are often found accidentally during routine exams.

Generally, benign liver lesions do not cause symptoms and, therefore, only need to be monitored with a CT and MRI scan to determine whether they are growing. Liver lesions that increase significantly in size can cause symptoms such as abdominal pain and digestive issues, which may prompt a need for surgical removal. Liver lesions with malignant characteristics are often biopsied to determine a diagnosis.

Malignant liver lesions are usually a metastatic nodule that appear due to cancer from other areas. It can also be a primary liver spot, which is also known as hepatocellular carcinoma. These typically appear in people with a history of liver diseases. For this reason, any time a liver lesion is detected in a person with cirrhosis, there is a chance that it may be cancer.

What causes liver lesions?

The appearance of a nodule in the liver can have several causes. The most common include:

1. Cyst or abscess

Most cases of liver lesions are usually just a cyst. Cysts are generally simple, benign and do not cause symptoms and therefore do not require treatment. Cysts that appear as a result of parasites can present with symptoms, and therefore can be surgically removed or drained. 

There are some cysts that are with genetic in origin, although these are more rare. People who are born with these types of cysts will tend to have multiple. In these cases, a liver transplant is the most recommended treatment. There are also times where cysts may be suspicious for malignancy, which require prompt treatment.

The liver lesion may also be an abscess, which requires antibiotic treatment, or drainage or aspiration if it is large in size.

Both liver cysts and abscesses are typically diagnosed with CT scans, an MRI or ultrasound. The results of these tests can help to guide the most appropriate treatment.

2. Focal nodular hyperplasia

This is the second most common type of liver lesion, and is most common in women between 20 and 50 years old. Most of the time they do not cause any symptoms and are found during routine examinations. This type of hyperplasia has a low chance of becoming malignant, but it does require periodic monitoring through ultrasound, CT or MRI imaging. Taking birth control pills do not cause liver lesions, but they can promote growth, which is why women with a known liver lesion who take birth control should be followed-up every 6 to 12 months.

Treatment with surgery is recommended when there are symptoms, or if the diagnosis is difficult to confirm. The lesion can also be removed if there is a suspicion that the liver lesion may be an adenoma, which is associated with a greater risk of malignancy or complications. 

3. Liver hemangioma

A hemangioma is a malformation of blood vessels that a person is born with. This is the most common type of liver lesion, and is often found during routine exams. They typically do not cause any symptoms. 

The diagnosis is usually confirmed with an ultrasound, CT or MRI. Liver hemangiomas that are less than 5 cm do not require any treatment or follow-up. However, hemangiomas that grow beyond 5 cm should be monitored every 6 months to 12 months. Sometimes it can grow quickly and compress liver tissue or other structures, causing pain and other symptoms. This growth can also be a sign of malignancy and must be removed with surgery.

People who play high-impact sports and women who intend to become pregnant, and who have large hemangiomas (even without symptoms) are at risk of bleeding or rupture of the hemangioma. This can be a very serious situations and may prompt surgical removal of the hemangioma. When a person has a large hemangioma and feels severe, sudden pain and a drop in blood pressure, they should seek urgent medical attention to investigate for a ruptured hemangioma.

4. Liver adenoma

An adenoma is a benign tumor in the liver, which is relatively rare. It is more common in women between the ages of 20 and 40, as taking birth control greatly increases the chances of developing one. Anabolic steroids and pregnancy can also increase the chances of developing an adenoma on the liver.

Adenomas are usually found during investigations that are prompted by abdominal pain, but they can also be found during routine exams. The diagnosis is confirmed through ultrasound, CT or MRI, which help to identify whether the liver lesion is an adenoma, focal nodular hyperplasia or liver cancer.

In most cases, adenomas are less than 1 cm and, therefore, they have a low risk of being cancer and causing complications like bleeding or rupture. They typically do not need treatment and can simply be monitored with regular testing. Adenomas that are larger than 1 cm have a greater risk for complications or turning into cancer, and may be need to be surgically removed.

When can a liver lesion by cancer?

When a person has no history of liver disease, a liver lesion is generally benign and is not a sign of cancer. However, a health history of liver disease, like cirrhosis or hepatitis, can increase the chance for cancer. This type of cancer is also referred to as hepatocellular carcinoma.

A cancerous liver lesion can also arise due to the presence of cancer in another location in the body, and can be a sign of metastasis.

Alcohol-induced cirrhosis and hepatitis are the main liver diseases that can lead to the appearance of hepatocellular carcinoma. Therefore, it is very important for patients with a history of liver to disease to carry out follow-up with a liver disease specialist as directed in order to reduce the chances of cancer.

A liver lesion is more likely to turn into cancer in patients with a history of blood transfusions, injectable drug use, alcohol abuse, family history of chronic liver disease such as cirrhosis.

Liver lesions that are metastases

Liver tissue is a common area for the emergence of metastases, especially when the primary cancer is in the digestive system, such as the stomach, pancreas and colon. Liver metastases are also common with primary breast or lung cancer.

Many times, a person may not have any symptoms when they discover that the cancer has already metastasized, other times they may have non-specific symptoms such as abdominal pain, increased abdominal volume, malaise, weakness and weight loss for no apparent reason, which may be the only signs of cancer. .