A liver lesion refers to an abnormal growth within the liver. These growths are frequently discovered unexpectedly when individuals undergo imaging tests, such as ultrasounds or CT scans, for unrelated medical reasons. Such findings, often termed “incidentalomas,” are asymptomatic and not related to the patient’s primary complaint. While their presence can raise concerns, understanding their nature is the first step in managing them.
Understanding Liver Lesion Types
Liver lesions can be categorized into two main types: benign (noncancerous) and malignant (cancerous). Benign lesions are quite common and typically do not spread to other parts of the body. These often require no treatment.
In contrast, malignant liver lesions are more serious and represent liver cancer. These can either originate in the liver, known as primary liver cancer (e.g., hepatocellular carcinoma), or they can be metastatic, meaning the cancer has spread to the liver from another part of the body, such as the colon or lung. Most cancerous liver tumors found are metastatic rather than primary.
Recognizing Symptoms
Benign liver lesions do not produce symptoms unless they grow large enough to exert pressure on surrounding organs. When this occurs, they may cause abdominal pain or discomfort, a feeling of fullness, or difficulty eating normal-sized meals. Very large benign lesions may cause pain due to pressure.
Malignant liver lesions often do not present with symptoms in their early stages. However, as they grow, various symptoms can emerge, including a lump or hard mass below the right rib cage, pain in the upper right side of the abdomen, or pain that radiates to the right shoulder blade or back. Jaundice, characterized by yellowing of the skin and eyes, can also occur due to high levels of bilirubin, a yellow pigment that the liver normally processes.
Factors Contributing to Liver Lesions
The exact causes of benign liver lesions are not always clear, but certain factors are associated with their development. Estrogen, whether from birth control pills or hormone replacement therapy, has been linked to the formation of some benign lesions. Scarring of the liver tissue, known as fibrosis, resulting from chronic liver disease, and smoking are contributing factors.
Malignant liver lesions develop when changes in cellular DNA lead to uncontrolled cell replication and growth. Chronic infections with hepatitis B virus (HBV) or hepatitis C virus (HCV) are primary risk factors for hepatocellular carcinoma, the most common type of primary liver cancer. Cirrhosis, a severe scarring of the liver often caused by chronic hepatitis or heavy alcohol consumption, significantly increases the risk. Other risk factors include obesity, diabetes, hemochromatosis (iron overload), and exposure to certain toxins like aflatoxin.
How Doctors Diagnose Liver Lesions
Diagnosing liver lesions begins with a physical examination and a review of the patient’s medical history, including any symptoms, risk factors, and family history. Imaging tests are fundamental in identifying and characterizing these growths. An ultrasound is the initial imaging test used, as it is non-invasive and effective at distinguishing between fluid-filled cysts and solid masses.
Computed tomography (CT) scans and magnetic resonance imaging (MRI) provide more detailed cross-sectional images of the liver and surrounding tissues. These scans help determine the size, location, and specific characteristics of the lesion, offering insights into whether it is benign or malignant and if it has spread. A contrast dye may be injected to enhance the visibility of the lesion and its blood supply during CT or MRI.
Blood tests also play a role in the diagnostic process. Liver function tests assess the overall health of the liver. Tumor markers, which are substances produced by cancer cells or in response to cancer, may be measured. Alpha-fetoprotein (AFP) is a common tumor marker for primary liver cancer, though elevated AFP levels can also occur in other conditions, so it is not used as a standalone diagnostic tool. If imaging and blood tests do not provide a clear diagnosis, a liver biopsy may be performed. This procedure involves taking a small tissue sample from the lesion, often guided by ultrasound or CT, for microscopic examination to confirm its nature.
Approaches to Treating Liver Lesions
Treatment strategies for liver lesions are highly individualized, depending on whether the lesion is benign or malignant, its size, location, and the patient’s overall health. For benign liver lesions, treatment may not be necessary, especially if they are small and asymptomatic. However, if a benign lesion grows large enough to cause symptoms like pain or discomfort, surgical removal may be recommended. This involves a liver resection, where the abnormal growth and a small margin of healthy tissue are removed.
For malignant liver lesions, a more aggressive approach is required. Surgical resection is the preferred treatment if the cancer is localized and can be completely removed while leaving sufficient healthy liver tissue to function. The liver has a remarkable ability to regenerate, even if up to 75% is removed. Where surgical removal is not feasible, other options are considered.
Chemotherapy involves using powerful drugs to destroy cancer cells, either systemically or through targeted delivery directly to the liver via transarterial chemoembolization (TACE). Radiation therapy uses high-energy beams to target and destroy cancer cells while minimizing damage to surrounding healthy tissue. Ablation therapies use heat or cold to destroy tumor cells by inserting a needle directly into the lesion. For select patients with early-stage liver cancer, particularly those with cirrhosis, a liver transplantation may be an option, where the diseased liver is replaced with a healthy donor liver.