Liver biopsy

Liver biopsy is the biopsy (removal of a small sample of tissue) from the liver. It is a medical test that is done to aid diagnosis of liver disease, to assess the severity of known liver disease, and to monitor the progress of treatment.

Liver biopsy is often required for the diagnosis of a liver problem (jaundice, abnormal blood tests) where blood tests, such as hepatitis A serology, have not been able to identify a cause. It is also required if hepatitis is possibly the result of medication, but the exact nature of the reaction is unclear. Alcoholic liver disease and tuberculosis of the liver may be diagnosed through biopsy. Direct biopsy of tumors of the liver may aid the diagnosis, although this may be avoided if the source is clear (e.g. spread from previously known colorectal cancer). Liver biopsy will likely remain particularly important in the diagnosis of unexplained liver disease. Non-invasive tests for liver fibrosis in alcoholic, nonalcoholic and viral liver diseases are likely to become more widely used.

If the diagnosis is already clear, such as chronic hepatitis B or hepatitis C, liver biopsy is useful to assess the severity of the associated liver damage. The same is true for haemochromatosis (iron overload), although it is frequently omitted. Primary biliary cirrhosis and primary sclerosing cholangitis may require biopsy, although other diagnostic modalities have made this less necessary.

Occasionally, liver biopsy is required to monitor the progress of treatment, such as in chronic viral hepatitis. It is an effective way to measure changes in the Ishak fibrosis score.

For the last century liver biopsy has been considered as the gold standard for assessing the stage and the grade of chronic liver disease. Consensus conference statements recommended liver biopsy in the management of almost all patients with hepatitis C and B.^{[citation needed]}

Biopsy results show significant variability (up to 40% for fibrosis diagnosis) which can lead to a wrong diagnosis. The result depends on the representativity of the punctured sample.

Only 5% of patients at risk of fibrosis have liver biopsy. In 2002, the consensus conferences in France and in the USA raised the possibility of treating patients with chronic hepatitis without liver biopsy. These conferences also underlined the necessity of developing reliable non-invasive tests that might be an alternative to liver biopsy both in hepatitis B and C.

Liver biopsy is generally a safe procedure, but it is invasive. Complications of liver biopsy are rare but potentially lethal. The majority of complications (60%) occur within two hours, and 96% occur within 24 hours following the procedure. Approximately 2–3% of patients undergoing liver biopsy require hospitalization for the management of an adverse event. Thirty percent of patients experience significant pain during the procedure.