Focal nodular hyperplasia is a medical condition that affects the liver. It is a form of tumor that is not dangerous to health and stems from minor liver developmental problems in the womb. The liver shows unusual cell growth and proliferation in a certain area, but the overall function of the organ is normal. The condition is often only diagnosed after a medical imaging procedure for another reason.
The condition is one of the most common liver tumors. Fortunately, the tumor cells are benign, which means they pose no significant risk to health. Focal nodular hyperplasia is a mass of cells that have grown abnormally compared to others of the liver. In most patients, the tumor area is recognizable by the presence of a scar along the center of the mass.
A commonly accepted explanation for the development of this condition is that that the affected person had deformed blood vessels in that particular area when developing as a fetus. With a lack of normal nutrient transport from the blood vessels, the liver cells grew in an unusual manner and produced a different arrangement of blood vessels. Due to this patching up of the affected area, the cells in the tumor are in different patterns compared to normal. More than one area on the liver can have tumor growths.
Although contraceptives were once thought to be involved in the development of this condition, as of 2011, this has been discounted as a cause. Women do tend to be more affected by the tumor than men. Taking oral contraceptives can, however, increase the risk of potential health effects from the tumor, although most people show no symptoms. Bleeding from the area or a rupture of the cells are possible complications.
More serious liver conditions, like cirrhosis or carcinomas, can also look like focal nodular hyperplasia through medical imaging techniques. New generations of imaging processes, like magnetic resonance imaging, show the presence of a tumor much more clearly than older techniques like X-rays. It is this increased sensitivity of machinery that allows medical professionals to identify the presence of tumors much more often than before. Even though the mass may not pose a risk to the health or the life of a patient, it may need to be removed in an operation if the cells are actually another, more dangerous form of tumor or if there is a significant risk that the presence of the tumor may result in complications.