Colonic serrated pathway lesions: Molecular and histologic changes in serrated colonic proliferations (Review)

Serrated polyps of the intestinal tract, specifically those within the colon, represent a wide variety of benign and neoplastic changes. Diagnostic entities include benign hyperplastic changes in prolapse, hyperplastic polyps (HPs), serrated adenomas (SAs) and carcinomas with serrated morphology. Recent developments in molecular pathology have confirmed the existence of additional neoplastic growths, with potentially aggressive behavior, called sessile serrated adenomas (SSAs). It is important to be aware of the distinct aspects of clinical significance and the varying outcomes associated with different serrated changes. In this article, important histologic diagnoses with serrated histology are reviewed and juxtaposed, where applicable, with their respective molecular pathways.