When and How to Perform a Liver Biopsy

After diagnosing your patient with liver disease through clinical examination, clinical biochemistry and/or diagnostic imaging, you may find yourself asking; ‘Should I be performing a liver biopsy for histopathology? Or is it more appropriate to perform a fine needle aspirate (FNA) for cytological examination?’. The answer is not always a simple one.

FNA can be performed on the liver, however there are diagnostic limitations to this test.Liver FNA is typically only useful in diagnosing generalised liver disease (e.g. hepatic lipidosisin cats, lymphoma, widespread metastatic disease). If localised disease is obvious (i.e. ahepatic mass), ultrasound guided FNA may also be diagnostically rewarding.

Ultimately, liver biopsy is often necessary for a definitive diagnosis (e.g. chronic hepatitis, nodular hyperplasia versus carcinoma). Liver histology can also provide useful prognostic information and will assist in determining the most appropriate treatment regime. Followup liver biopsy can be used to monitor disease progression and assess whether a treatment regime is effective.

Liver biopsy specimens are an important diagnostic tool in suspected cases of acute orchronic hepatitis and for other suspected hepatopathies in a range of species. Sampling technique is key to maximising the chances of an accurate and prognostically relevant diagnosis.

The American College of Veterinary Internal Medicine (ACVIM) consensus statement on the diagnosis and treatment of chronic hepatitis in dogs recommends that at least 12-15 portalareas are included in the evaluated biopsy samples. This means that larger biopsy samplesare preferred to core biopsies, although the latter can be diagnostically useful for some conditions.

It is also important to remember that disease can vary markedly between liver lobes due tovariation in blood supply and bile drainage. Therefore, where possible multiple liver lobes should be sampled for histopathology and/or ancillary testing (i.e. hepatic copper levels).

Your tissue samples should always be accompanied by a summary of the pertinent clinical history, diagnostic imaging results and any unusual haematological and biochemical findings. Pathologists use this information when corroborating the histologic findings to assist in making the most appropriate diagnosis.

  • 1 full 14 G (2-cm long) needle biopsy
  • Half of a 5 mm laparoscopic biopsy sample
  • 1 full length 18 G needle only provides 3-5 mg of wet tissue.
  • ** If you are taking tissue for culture AND copper analysis please rememberto take twice the amount of tissue listed above.