Diagnostic Significance and Reproducibility of Non-conventional Dysplasia and Serrated Epithelial Change in Inflammatory Bowel Disease.

Although most dysplastic lesions in inflammatory bowel disease resemble sporadic adenomas, several distinct morphologic patterns, collectively termed non-conventional dysplasia, have recently been described. Accurate evaluation of these lesions is essential, as many are endoscopically invisible or flat and are frequently associated with synchronous and/or metachronous neoplasia, conferring an elevated risk of subsequent advanced neoplasia. Similarly, serrated epithelial change (SEC) is commonly associated with invisible/flat synchronous/metachronous neoplasia, including non-conventional dysplasia and advanced neoplasia, often occurring in the same colonic segment. This review describes the morphologic criteria, clinicopathologic features, potential clinical relevance, and recommended reporting practices for non-conventional dysplasia and SEC.