Figure 1: (a) Colonoscopic images after spraying with 0.2% indigo carmine dye, showing a nongranular LST in the rectum. The surface showed mild redness. Extensibility of the tumor on insufflation was relatively good. (b) Magnifying endoscopic images after the application of 0.05% crystal violet stain, showing a type VN pit pattern characterized by an amorphous structure of part of the tumor. (c) EUS images, showing severe narrowing of the third layer in part of the tumor (arrow). Cancer with deep submucosal invasion was diagnosed. (d) and (e) Histopathological findings of the surgically resected specimen. (d) The longest diameter of the tumor was 20 mm. Although most of the tumor was confined to the mucosa, part of the lesion invaded the middle layer of the submucosa (arrow). The diagnosis was a well-differentiated tubular adenocarcinoma. (e) The intramucosal part of the tumor had become detached at the site of submucosal invasion.