Page 216 - WSAVA2018
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 25-28 September, 2018 | Singapore
Interpreting the liver biopsy histology report
On the liver biopsy, the clinician should NOT just read the bottom line diagnosis but should read the whole report. It is important first in dogs to be sure this IS
a primary hepatitis and not a reactive hepatopathy. Sometimes the final diagnosis isn’t clear for example if the pathologist has written ‘reactive hepatitis’ without a full explanation, the clinician may believe this is primary liver disease when in fact it is secondary. The presence of inflammatory cells alone does not mean primary disease – if there is no fibrosis and no evidence of hepatocyte death, this is not a primary hepatitis.
In primary hepatitis cases in dogs, the clinician should assess the amount and distribution of inflammation and the types of inflammatory cells involved, the degree and distribution of fibrosis and the presence of any obvious cause including build up of copper. Combining all this information allows optimal treatment of the patient. It is not possible – and indeed is potentially dangerous – to give specific treatments for CH (such as copper chelators and steroid or other immunosuppressive therapy) without biopsy confirmation of disease. It is very important that
all canine hepatitis cases have a copper stain performed and if the laboratory has not already done this, it should be requested.
If a significant amount of copper is found in the biopsy, in proportion to the severity of the disease, copper storage disease should be strongly suspected and treated with chelation and dietary therapy. If copper storage disease is ruled out, the type and distribution
of inflammation present may suggest a cause for the disease. If there is a strong neutrophilic component, particularly if it is periportal, there may be a chronic hepatic or biliary tract infection and consideration should be given to culturing bile or liver and ruling out chronic partial extrahepatic biliary obstruction or cholecystitis. Ideally, a bile sample should be taken for culture every time a liver biopsy is taken, as a routine procedure:
it is very annoying to get back the biopsy result and then wish you had taken a bile culture at the time! If there is a granulomatous inflammatory response, it might be worth considering PCR for bartonella or other unusual infections or submitting a sample to Cornell
or Bristol UK for Fluorescent in situ hydridisation (FISH) for bacteria. If there is a dense lymphoplasmacytic inflammatory component, an autoimmune aetiology might be considered. However, it is important to note that lymphoplasmacytic infiltration might also be seen in viral disease and at the current state of knowledge it is impossible to be differentiate between putative viral and autoimmune hepatitis in dogs, so the most difficult decision to make may be over the use of steroids.
Willard MD, Weeks BR, Johnson M. (1999). Fine-needle aspirate cytology suggesting hepatic lipidosis in four cats with infiltrative hepatic disease. J Feline Med Surg;:215-20.
Cole TL, Center SA, Flood SN, Rowland PH, Valentine BA, Warner KL, Erb HN. (2002) Diagnostic comparison of needle and wedge biopsy specimens of the liver in dogs and cats. J Am Vet Med Assoc;220:1483-90.

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