Management of Rectal Polyps with High Malignancy Risk

Introduction to Classification Systems and Risk Stratification

The American Gastroenterological Association recommends that for a rectal polyp showing high-risk features on JNET Type 3, KUDO Type V, or concerning CONNECT patterns, endoscopic resection should not be attempted if the lesion is non-pedunculated, and instead, biopsy the area of surface disruption, tattoo the site, and refer directly to a colorectal surgeon 1
The National Comprehensive Cancer Network suggests that JNET Type 3 is characterized by loose vessel areas with interruption of thick vessels, and amorphous surface areas, which predicts deep submucosal invasive cancer 2, 3
The European Society of Gastrointestinal Endoscopy indicates that KUDO Type V, specifically VN and VI patterns, indicate deep invasion 1, 2, 3
The National Institute for Health and Care Excellence states that any one of the NICE 3 features has 94% accuracy and 96% negative predictive value for deep submucosal invasion 1

For non-pedunculated lesions with high-risk features, the American Society for Gastrointestinal Endoscopy recommends performing limited cold forceps biopsy only in the area of surface feature disruption to confirm histology, tattooing the lesion, and referring directly to colorectal surgery 1, 4
The American College of Gastroenterology advises that for pedunculated lesions with high-risk features, endoscopic polypectomy should be performed because the stalk allows assessment of invasion depth using Haggitt classification, and en-bloc resection provides intact specimen for accurate pathologic assessment 1, 5, 6
The European Society of Medical Oncology recommends that after resection, histologic evaluation determines the need for surgical resection based on depth of submucosal invasion, presence of lymphovascular invasion, poor differentiation, and positive margins 1, 5, 6, 8

The Japanese Gastric Cancer Association states that curative resection requires en-bloc resection with negative horizontal and vertical margins, submucosal invasion <1000 μm, well to moderately differentiated histology, no lymphovascular invasion, and no tumor budding 5, 6, 8, 9
The National Comprehensive Cancer Network indicates that if any criterion is not met, surgical resection with lymph node dissection is required because the risk of lymph node metastasis increases to 10-18% with deep submucosal invasion 1, 6