Modern Endoscopic Management of Flat Colonic Neoplasia : Endoscopy | June 2026

Introduction:

Non-pedunculated colonic neoplasia (NPCN), including flat and sessile colorectal lesions, is being detected with increasing frequency due to widespread colorectal cancer screening and advances in high-definition endoscopy. Compared with pedunculated polyps, these lesions present greater challenges because of their higher risk of submucosal invasion, incomplete resection, and recurrence. Consequently, accurate lesion characterization and appropriate selection of resection technique are essential for optimal patient outcomes.

Problem Statement:

The expanding range of endoscopic imaging technologies and resection techniques has created increasing complexity in the management of NPCN. Clinicians must determine which lesions can be safely treated with cold resection techniques, which require advanced endoscopic interventions, and which should be referred for surgery. Clear guidance is needed to integrate evolving evidence into routine clinical practice.

Summary:

This review provides a contemporary overview of the diagnosis and management of NPCN, highlighting major advances that have reshaped endoscopic practice over the past decade. Modern optical diagnosis systems, including NICE, JNET, and Kudo pit pattern classifications, now enable more accurate real-time assessment of lesion histology and invasion depth, facilitating informed therapeutic decision-making. Cold snare polypectomy and cold EMR have emerged as preferred approaches for small and intermediate-sized lesions because of their excellent safety profile and high rates of complete resection. For lesions measuring 20 mm or larger, piecemeal EMR combined with systematic margin ablation using snare-tip soft coagulation has become the standard approach, substantially reducing recurrence rates. The review also discusses the growing role of underwater EMR, cap-assisted EMR, and endoscopic full-thickness resection for challenging fibrotic or non-lifting lesions. ESD remains an important technique when en bloc resection is required, particularly in lesions with suspected superficial submucosal invasion, although its adoption varies according to local expertise and service infrastructure. Looking ahead, artificial intelligence-assisted optical diagnosis, standardized training pathways, and robust quality metrics are expected to further improve outcomes. Overall, the review reinforces a lesion-specific, evidence-based approach to NPCN, emphasizing accurate optical diagnosis and tailored resection strategies as the foundation of high-quality colorectal endoscopic care.