Cholangiopathies from a Pathologist's Perspective: The Role of Liver Biopsy in Routine Diagnostic Practice

The biliary tree comprises a three-dimensional network of intrahepatic and extrahepatic ducts lined by biliary epithelium (cholangiocytes). The bile ducts and cholangiocytes may be affected by a broad spectrum of disorders collectively referred to as cholangiopathies. These conditions are classified based on anatomical aspects (predominantly affecting small or large bile ducts), aetiopathogenesis (immune-mediated, toxic and drug-induced, ischaemic, infectious, genetically determined, or neoplastic), and the predominant morphological pattern of injury (inflammatory or non-inflammatory). While abnormalities in medium-sized and large bile ducts are typically detected using radiological methods, the diagnosis of small duct cholangiopathies continues to rely primarily on histopathological evaluation of liver tissue. This review summarises the key morphological features of the most clinically significant cholangiopathies, focusing on histopathological changes observed in liver biopsy.