(a) A 6-mm-diameter carcinoid tumor in the lower rectum. (b) Thinning of the third layer corresponding to the submucosal layer by endoscopic ultrasonography. (c) Submucosal injection with hyaluronic acid. (d) Circumferential mucosal incision with a needle knife. (e) Snaring with a 27-mm oval snare. (f) After resection. (g) Histopathologically, the vertical distance of the resection margin was relatively sufficient from the lower edge of the tumor.
