Liver Biopsy Health Article

Definition

A liver biopsy is a medical procedure performed to obtain a small piece of liver tissue for diagnostic testing. The sample is examined under a microscope by a doctor who specializes in the effects of disease on body tissues (a pathologist) to detect abnormalities of the liver. Liver biopsies are sometimes called percutaneous liver biopsies, because the tissue sample is obtained by going through the patient's skin. This is a useful diagnostic procedure with very low risk and little discomfort to the patient.

Purpose

A liver biopsy is usually done to evaluate the extent of damage that has occurred to the liver because of chronic and acute disease processes or toxic injury. Biopsies are often performed to identify abnormalities in liver tissues after imaging studies and radiopharmaceutical scans have failed to yield clear results.

A liver biopsy may be ordered to diagnose or stage any of the following conditions or disorders:

• jaundice
• cirrhosis
• repeated abnormal results from liver function tests
• alcoholic liver disease
• unexplained swelling or enlargement of the liver (hepatomegaly)
• suspected drug-related liver damage such as acetaminophen poisoning
• hemochromatosis, a condition of excess iron in the liver
• intrahepatic cholestasis, the build up of bile in the liver
• hepatitis
• primary cancers of the liver, such as hepatomas, cholangiocarcinomas, and angiosarcomas
• metastatic cancers of the liver (These are over 20 times as common in the United States as primary cancers.)
• post liver transplant to measure graft rejection
• fever of unknown origin
• suspected tuberculosis, sarcoidosis, or amyloidosis

Precautions

When performing the liver biopsy and blood collection that precedes it, the physician and other health care providers should follow universal precautions for the prevention of transmission of bloodborne pathogens. Some patients should not have percutaneous liver biopsies. They include those with any of the following conditions:

• a platelet count below 100,000
• a prothrombin test time greater than three seconds over the reference interval
• a liver tumor with a large number of veins
• a large amount of abdominal fluid (ascites)
• infection anywhere in the lungs, the lining of the chest or abdominal wall, the biliary tract, or the liver
• benign tumors (angiomas) of the liver (These tumors consist mostly of enlarged or newly formed blood vessels and may bleed heavily.)
• biliary obstruction