The liver is a vital organ that plays an important part in the digestive process. It can be affected by a number of diseases and conditions. Lesions, damaged areas on the liver, can be classified as either benign or cancerous. Benign lesions can be the result of hemangiomas and focal nodular hyperplasia, among other conditions. Cancerous lesions are the result of the uncontrolled growth of cancer cells in and on the liver.
Doctors suspect that focal nodular hyperplasia (FNH) may be caused by a defect in the way the veins and arteries are formed within the liver. This is the second most common type of liver lesion. They may be present for years without causing any problems since there are few symptoms associated with them. FNH rarely becomes cancerous and lesions are only removed if they cause problems with liver function or the patient’s comfort.
Hemangiomas are the result of the overgrowth of blood vessels in the liver. These are the primary type of benign liver lesions. As with FNH, hemangiomas are generally discovered by accident, as they do not often cause symptoms. For this reason they are rarely treated. There is no evidence that an untreated liver hemangioma is at risk for becoming cancerous.
A third type of benign liver lesions are adenomas. These are relatively uncommon, and are prevalent more in women than in men. They are thought to be triggered by the use of oral contraceptives and other medications involving large amounts of estrogen. People with diabetes mellitus are also more prone to developing this type of lesion.
Adenomas may cause pain, alerting both patient and doctor to a potential problem. There is some risk that adenomas may become cancerous, and there is often a fairly high risk of sudden hemorrhage. The risk of bleeding due to the rupture of an adenoma is quite high in pregnant women and should be taken very seriously. For these reasons, these liver lesions are often removed when they are discovered.
The other primary cause of liver lesions is cancer, which is considered malignant and usually continues to grow unless it is treated. In such cases there are typically multiple lesions on the liver, and they may spread to other parts of the body as well. Cancerous lesions are typically diagnosed through the performance of a biopsy, where a small fragment of the lesion is evaluated microscopically. These lesions must be treated aggressively to stop them from destroying the liver.