Liver lesions are cell abnormalities found on or in the liver, the largest glandular organ in the body. Most types are benign, but some are associated with cancer. Many lesions don't cause symptoms until they become very large, so they are commonly discovered accidentally during a medical exam for another condition. Most liver abnormalities are treatable, though malignant tumors can be very dangerous if not addressed promptly.
The most common types of benign liver lesions are hemangiomas, which are abnormal formations of blood vessels. It's not entirely clear why they form, but they generally don't cause any symptoms, and only rarely require treatment. Many people also have liver cysts, which usually don't require treatment unless they become very large, in which case they can be drained or surgically removed. Some people have a genetic condition called polycystic liver disease, which causes them to develop multiple liver cysts. Though the cysts themselves are not cancerous, the condition does have to be treated, either with surgery or a liver transplant.
Another common cause of liver lesions is focal nodular hyperplasia, which is a type of tumor. It is thought to be caused by damaged or abnormal blood vessels in the liver. Like a hemangioma, focal nodule hyperplasia generally does not cause any symptoms, and many people live with it their entire lives without knowing they have it. A rarer type of benign liver tumor is a hepatocellular adenoma, which is associated with increased levels of estrogen in the body, such as those caused by old, high-dosage oral contraceptives. Unless an adenoma grows particularly large, it generally does not require treatment.
The most common type of malignant liver lesions is hepatocellular carcinoma. It is most often found in men from African and Asian countries, particularly in areas with lots of hepatitis B and C. It can also be connected with a genetic condition called hemochromatosis, which causes a person's body to absorb too much iron, which damages the liver. Malignant lesions can also happen when cancer in another part of the body metastasizes, or spreads to the liver. This is common in patients in the later stages of cancer.
The majority of liver tumors do not cause any symptoms, and the liver continues to function normally. In some cases, a person may have pain and swelling of the abdomen, nausea, vomiting, or changes in the color of the urine or stool. More serious lesions might lead to jaundice and a fever. This can be a sign of a medical emergency, so anyone with these symptoms should see a healthcare provider immediately.
Most liver lesions are diagnosed accidentally when a healthcare provider is doing an ultrasound or with a Computed Tomography (CT) scan on someone for another health issue. Once a liver lesion is suspected, further imaging studies are done to confirm the size and nature of the tumor. In some cases, a biopsy may be necessary. This is a procedure in which a small amount of tissue is removed for analysis in a lab. Blood tests can also be used to look for elevated levels of alpha-fetoprotein (AFP), which is associated with liver cancer, though the test is only about 60% accurate.
Treatment and Prognosis
Benign lesions typically don't require any treatment, unless they start to grow too large and damage the surrounding area, in which case they are usually surgically removed. If the surgery is successful, a healthy and fit patient can regenerate up to three-fourths of his or her liver, making the prognosis for a benign lesion very good.
The treatment and prognosis for malignant lesions largely depends on how early they are diagnosed. Unfortunately, many are diagnosed fairly late. Options for treatment include chemotherapy, radiation, and surgery. The prognosis for most hepatocellular carcinomas is fairly poor, even if they are diagnosed early, as chemotherapy and radiation cannot completely cure them, and it's difficult to completely remove them with surgery. Even if surgery is successful, a person is still at risk for liver failure during recovery.