Endoscopic Assessment and Management of Colorectal Serrated Lesions: Current Comparative Practice, Challenges, and Future Directions

Serrated-carcinoma pathway accounts for approximately 15%-30% of sporadic colorectal cancers (CRC) and contributes disproportionately to right-sided interval cancers. Key precursors include sessile serrated lesion (SSL) and SSL with dysplasia (SSLD); traditional serrated adenoma, and also the recently described superficially serrated adenoma which warrants attention. However, high-quality evidence guiding best practice for resection indications, technique selection, and post-resection surveillance intervals remains limited and varied, with differences between Western and Japanese guidelines. This narrative review integrates clinicopathologic and practical perspectives to provoke further discussion for a standardized universal guideline approach. For nondysplastic SSLs, cold polypectomy techniques may be considered in selected lesions with defined margins and detailed documentation, whereas those with suspected dysplasia, non-lifting or scarring, requiring en bloc resection, favor endoscopic mucosal resection or endoscopic submucosal dissection for accurate histopathology. Surveillance should be prioritized by histopathology and completeness of resection, with an index shorter interval assessment of the resection site at 6-12 months after piecemeal resection or when margins are involved or indeterminate, followed by risk-tiered intervals. Because the detection of serrated lesions determines resection type, quality and surveillance interval, endoscopists should standardize bowel preparation, lesion assessment after mucus cap clearance, use image-enhanced endoscopy when appropriate, and apply targeted dye spray when borders are indistinct. Finally, we outline priority research; prospective, serrated lesion-focused cohorts and trials-to ascertain durable outcomes of cold snare resection strategies, refine surveillance intervals, and reconcile regional practice differences, with the overarching goal of reducing post-colonoscopy interval CRC and overall CRC incidence with high-quality colonoscopy.