(See also Overview of Liver Tumors.)
Hepatic granulomas are small abnormal clumps of cells that form when certain disorders are present or certain drugs are taken.
Granulomas themselves usually cause no problems, but the disorders that cause them may.
Granulomas have many causes. The most common are
Certain disorders that affect the whole body (often infections, such as tuberculosis and schistosomiasis)
Granulomas occur less commonly in liver disorders but may be present in primary biliary cholangitis.
Granulomas may form when cells of the immune system gather to respond to irritants or to defend the body against foreign substances in the liver. Usually, liver function is unaffected. However, granulomas may form as part of widespread inflammation, which may be a reaction to a drug or to an infection. If inflammation is widespread, the liver may malfunction. Rarely, the inflammation results in scar tissue and high blood pressure in the veins that bring blood from the intestine to the liver (called portal hypertension).
Granulomas themselves typically cause no symptoms. The liver may enlarge slightly, and mild jaundice (a yellowish discoloration of the skin and the whites of the eyes) may develop. Other symptoms, if they develop, result from the disorder causing the granulomas. Granulomas caused by sarcoidosis may disappear spontaneously or persist for years without causing any noticeable symptoms.
Idiopathic granulomatous hepatitis is a rare disorder of unknown cause. It causes granulomas, fever, muscle aches, and fatigue. These symptoms often occur intermittently for years.
Doctors ask questions about drug use and other disorders that could cause granulomas. Doctors also do blood tests to evaluate liver function and imaging tests, such as ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI). However, the results may be inconclusive. Biopsy (removal of a small sample of liver tissue with a needle for examination under a microscope) may be needed to confirm the diagnosis.
Other tests, such as cultures, may be needed to identify the cause.
The underlying disorder is treated. Stopping a drug that can cause granulomas or treating an infection usually causes the granulomas to disappear.
Sometimes corticosteroids are used to treat sarcoidosis, but whether they prevent the disorder from progressing is uncertain.