Endoscopic management of colorectal polyps: From benign to malignant polyps

Figure 5 Kudo and Kikuchi classification (adapted from Kikuchi et al[37]). Depth of submucosal invasion is divided into Sm¹ (invasion into the upper third of the submucosa), Sm² (invasion into the middle third), Sm³ (invasion into the lower third). In this illustration, the adenocarcinoma is a superficial lesion with Sm1 invasion.