Liver lesions refer to any abnormal growths or areas found on the liver. These irregularities can vary in size, shape, and composition, appearing as either solid masses or fluid-filled sacs.
Understanding Liver Lesions
A liver lesion represents an area of liver tissue that appears different from the surrounding healthy tissue. These lesions can be either benign, meaning non-cancerous, or malignant, indicating the presence of cancer.
Common Types of Liver Lesions
Liver lesions encompass a range of types, broadly categorized as benign or malignant. Each type has distinct characteristics.
Benign Liver Lesions
Benign lesions are non-cancerous growths that do not spread to other parts of the body. They are often discovered incidentally.
Hemangiomas are the most common type of benign liver tumor, consisting of a tangle of abnormal blood vessels. These growths are usually asymptomatic. Most hemangiomas are small, averaging about 3 centimeters, and do not cause symptoms unless they grow large, which can lead to abdominal pain or a feeling of fullness.
Liver cysts are fluid-filled sacs that can develop on the liver. Most liver cysts are benign and do not cause symptoms unless they become large enough to create discomfort or pressure. Some individuals may have simple cysts, while others might have polycystic liver disease, an inherited condition characterized by multiple cysts throughout the liver.
Focal nodular hyperplasia (FNH) is a non-cancerous mass of abnormal liver cells that forms around a central scar. This type of lesion is the second most common benign liver tumor after hemangiomas. FNH does not cause symptoms and rarely requires treatment.
Liver adenomas are benign tumors that occur in women and have been linked to the use of oral contraceptives or anabolic steroids. These lesions can grow large and carry a risk of bleeding or transforming into cancer. Due to these potential risks, adenomas warrant careful monitoring or removal.
Malignant Liver Lesions
Malignant lesions are cancerous growths that can originate in the liver or spread to it from other parts of the body. These require intervention and treatment.
Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. HCC develops in individuals with chronic liver diseases, such as cirrhosis, caused by hepatitis B or C infection, or heavy alcohol consumption.
Metastatic liver cancer is cancer that has spread to the liver from a primary tumor elsewhere in the body. The liver is a common site for metastasis due to its rich blood supply. Cancers from the colon, rectum, breast, or lung are frequent sources of liver metastases. These secondary liver cancers are much more common than primary liver cancers.
How Liver Lesions Are Discovered
Liver lesions are frequently discovered incidentally during imaging tests performed for other medical reasons. Most benign liver lesions do not cause symptoms, so they often go unnoticed until an imaging scan is conducted.
Ultrasound is often the initial imaging method used to detect liver lesions. It is a non-invasive and cost-effective technique that uses sound waves to create images of the liver, helping to differentiate between fluid-filled cysts and solid masses. While ultrasound can identify the presence of a lesion, more advanced imaging is needed for detailed characterization.
Computed tomography (CT) scans provide more detailed cross-sectional images of the liver. A CT scan can offer specific information about a lesion’s size, shape, and exact location. Contrast agents are often used with CT scans to enhance image clarity and help characterize the lesion further.
Magnetic resonance imaging (MRI) is an effective method for evaluating liver lesions due to its ability to provide detailed soft tissue images without using ionizing radiation. MRI offers good contrast resolution, which aids in distinguishing between different types of liver tissues and lesions. Specialized MRI techniques, including those with contrast agents, are often employed to gain more insights into the lesion’s nature.
What Happens After a Liver Lesion is Found
Once a liver lesion is discovered, the next steps involve a thorough evaluation to determine its nature and appropriate management. This process aims to differentiate between benign and malignant lesions, as the approach to care varies.
Initial evaluation often includes additional imaging studies, such as specialized CT or MRI scans, to gather more detailed information about the lesion’s characteristics. Blood tests may also be conducted to assess overall liver function and check for specific markers that could indicate the presence of certain conditions, including cancer.
In many cases, if imaging suggests a benign lesion and the individual is asymptomatic, a “watchful waiting” approach may be adopted. This involves periodic follow-up imaging to monitor the lesion for any changes in size or appearance over time. However, if there is uncertainty about the lesion’s nature or if it exhibits suspicious features, a liver biopsy may be recommended. During a biopsy, a small tissue sample is extracted from the lesion, usually guided by imaging, and then examined under a microscope to confirm the diagnosis.
Management strategies for liver lesions depend on the diagnosis. Benign lesions that are small and cause no symptoms do not require treatment. However, larger benign lesions that cause discomfort or carry a risk of complications, like bleeding, may be surgically removed. Malignant lesions, or liver cancers, require treatment, which can include surgical removal of the tumor, medical therapies, or other interventional procedures, depending on the type and stage of the cancer.