A liver lesion refers to any abnormal growth or area within the liver. These growths can range significantly in their characteristics, from simple fluid-filled sacs to solid masses. While the term “lesion” can sound alarming, many liver lesions are discovered incidentally during imaging tests for other conditions and are not serious. Understanding the different types of liver lesions and their potential implications is important for determining when medical evaluation is warranted.
Understanding Different Liver Lesions
Liver lesions are broadly categorized as either benign (non-cancerous) or malignant (cancerous). Benign lesions are far more common and generally do not spread to other parts of the body or cause significant health issues. The most common type of benign liver lesion is a hemangioma, which is a tangle of abnormal blood vessels. Hemangiomas are found in up to 5% of adults and typically do not cause symptoms unless they grow very large.
Another frequent benign lesion is focal nodular hyperplasia (FNH), characterized by a mass of abnormal cells often containing a central scar. FNH is the second most common benign liver tumor and is usually asymptomatic, rarely growing or bleeding, and with no malignant potential. Hepatic adenomas are less common benign tumors, primarily found in women who use oral contraceptives or athletes using anabolic steroids. They can grow large, potentially rupturing or hemorrhaging, and carry a small risk of malignant transformation.
In contrast, malignant liver lesions are serious and require intervention. These can be primary liver cancers or secondary (metastatic) cancers. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, often associated with chronic liver diseases like cirrhosis or hepatitis B and C infections. Metastatic liver cancer is even more prevalent in the United States and Europe, commonly spreading from cancers of the colon, lung, or breast.
Symptoms That Warrant Concern
Many liver lesions, especially benign ones, do not cause any symptoms and are often discovered incidentally during imaging for other reasons. However, certain symptoms can indicate a more concerning liver lesion that requires prompt medical attention. Persistent abdominal pain, particularly in the upper right quadrant of the abdomen or under the right shoulder, can be a sign. This pain may be accompanied by a feeling of fullness, nausea, or vomiting.
Other symptoms warranting evaluation include unexplained weight loss and loss of appetite. Jaundice, characterized by yellowing of the skin and the whites of the eyes, is a serious sign indicating a buildup of bilirubin, which can occur if a lesion blocks bile ducts or impairs liver function. Dark urine and pale stools can also accompany jaundice. Persistent fatigue, a lump below the rib cage, and bloating can also indicate a problematic liver lesion.
How Liver Lesions Are Evaluated
When a liver lesion is suspected or detected, a doctor typically begins with a comprehensive medical history and physical examination. Imaging tests are fundamental in characterizing liver lesions. Ultrasound, computed tomography (CT) scans, and magnetic resonance imaging (MRI) are commonly used, providing detailed images of the liver and helping to determine the lesion’s size, location, and specific features. MRI is particularly sensitive for identifying specific characteristics of lesions like focal nodular hyperplasia.
Blood tests complement imaging by assessing liver function and looking for specific markers. Certain tumor markers, such as alpha-fetoprotein (AFP), may also be measured, as elevated levels can indicate hepatocellular carcinoma. If imaging and blood tests are inconclusive, or if malignancy is strongly suspected, a liver biopsy may be necessary. This procedure involves taking a small tissue sample from the lesion, which is then examined under a microscope to confirm a diagnosis.
Next Steps and Outlook
The course of action following the detection of a liver lesion depends entirely on its diagnosis. For most benign liver lesions, such as hemangiomas and focal nodular hyperplasia, no treatment is typically required because they are usually asymptomatic and do not progress to cancer. Regular monitoring with imaging studies may be recommended to ensure the lesion does not change in size or character. However, if a benign lesion grows large enough to cause symptoms like pain or poses a risk of complications, surgical removal may be considered.
For malignant liver lesions, treatment options vary widely based on the type of cancer, its size, location, and whether it has spread. Treatment strategies for primary liver cancers like hepatocellular carcinoma can include surgery to remove the tumor, liver transplant for early-stage cases, or localized therapies such as radiofrequency ablation (heating cancer cells) or cryoablation (freezing cancer cells). Embolization therapy, which blocks blood flow to the tumor, and radiation therapy may also be used. Systemic treatments like chemotherapy, targeted therapy, and immunotherapy are options for more advanced or widespread cancers.