Medical liver biopsies can be daunting for both the resident and consultant pathologist alike. The range of morphological changes which may be encountered and the list of possible disease processes responsible for these present certain challenges for those attempting to compose a clinically useful report. In this session we will talk through an approach to example cases which illustrate a few of the more commonly encountered patterns.

Medical liver biopsies can provide valuable information regarding liver disease, that is additional to the wide spectrum of non-invasive blood-based and radiology-based tests that are now available for clinicians investigating patients with liver disease. Histopathological assessment of liver biopsies requires knowledge of the clinical setting in which the biopsy was taken and the results of relevant non-invasive tests. Biopsy adequacy can be assessed from the core length and the presence of artefacts such as fragmentation. Even within good-sized biopsies, disease characterised by patchy liver involvement may not be represented characteristically, or at all, within the biopsy. Clinicians and pathologists should remember that a typical liver biopsy represents around 1/50,000 of the liver! A systematic approach to biopsy examination is important e.g., the initial impression, the overall architecture, the portal tracts and then the parenchyma. The range of “special stains” provided for medical liver biopsy reporting varies between laboratories. Several stains can be used to assess architecture and some have other uses e.g., copper-binding protein identification. Stains highlighting possible alpha-1-antitrypsin globules and iron are important, especially since the associated diseases may be asymptomatic but cause serious liver disease. It is important always to consider the possibility of a second disease process. Cytokeratin immunohistochemistry may be very useful e.g., cytokeratin 7 for highlighting native bile ducts, a ductular reaction and intermediate hepatobiliary cells in the setting of chronic biliary tract disease. A histopathology report for a medical liver biopsy should be prepared using a structured approach, describing the key histopathological features clearly and then providing a clinicopathological comment. A close working relationship with the clinicians managing patients with liver disease is essential for histopathologists reporting liver biopsies, particularly since many histopathological appearances within these specimens possess more than one possible cause and because patients with liver disease often have complex medical histories.