Morphological aspects of small-duct cholangiopathies:A minireview

The biliary system consists of intrahepatic and extrahepatic bile ducts lined by biliary epithelial cells(cholangiocytes).Bile ducts and cholangiocytes are affected by a variety of disorders called cholangiopathies,which differ in aetiology,pathogenesis,and morphology.Classification of cholangiopathies is complex and reflects pathogenic mechanisms(immune-mediated,genetic,drug-and toxininduced,ischaemic,infectious,neoplastic),predominant morphological patterns of biliary injury(suppurative and non-suppurative cholangitis,cholangiopathy),and specific segments of the biliary tree affected by the disease process.While the involvement of large extrahepatic and intrahepatic bile ducts is typically visualised using radiology imaging,histopathological examination of liver tissue obtained by percutaneous liver biopsy still plays an important role in the diagnosis of cholangiopathies affecting the small intrahepatic bile ducts.To increase the diagnostic yield of a liver biopsy and determine the optimal therapeutic approach,the referring clinician is tasked with interpreting the results of histopathological examination.This requires knowledge and understanding of basic morphological patterns of hepatobiliary injury and an ability to correlate microscopic findings with results obtained by imaging and laboratory methods.This minireview describes the morphological aspects of small-duct cholangiopathies pertaining to the diagnostic process.

Histopathological assessment of the microscopic activity in inflammatory bowel diseases:What are we looking for?

Advances in diagnostics of inflammatory bowel diseases(IBD)and improved treatment strategies allowed the establishment of new therapeutic endpoints.Currently,it is desirable not only to cease clinical symptoms,but mainly to achieve endoscopic remission,a macroscopic normalization of the bowel mucosa.However,up to one-third of IBD patients in remission exhibit persisting microscopic activity of the disease.The evidence suggests a better predictive value of histology for the development of clinical complications such as clinical relapse,surgical intervention,need for therapy escalation,or development of colorectal cancer.The proper assessment of microscopic inflammatory activity thus became an important part of the overall histopathological evaluation of colonic biopsies and many histopathological scoring indices have been established.Nonetheless,a majority of them have not been validated and no scoring index became a part of the routine bioptic practice.This review summarizes a predictive value of microscopic disease activity assessment for the subsequent clinical course of IBD,describes the most commonly used scoring indices for Crohn's disease and ulcerative colitis,and comments on current limitations and unresolved issues.