A pilot randomized control study to evaluate endoscopic resection using a ligation device for rectal carcinoid tumors

Figure 1 Endoscopic ultrasonography demonstrating a hypoechoic solid tumor in the superficial submucosa without involvement of the muscularis propria.

Figure 2 Endoscopic appearance of a carcinoid tumor, 6 mm in diameter, located in the lower portion of the rectum. A: Yellowish appearance with a smooth surface before treatment; B: injection of submucosal saline solution into the base of the lesion using needle forceps; C: aspiration of a carcinoid tumor into the ligation device; D: snare resection performed below the band by using blend electrosurgical current.

Figure 3 Section of a rectal carcinoid tumor obtained by endoscopic mucosal resection. A: Low-power photomicrographs demonstrating a carcinoid tumor, which is present in both the mucosa and submucosa of the rectum, with tumor-free surgical margins (HE, original magnification x 4); B and C: tumor cells arranged in nests and rosette-like structures, with absence of nuclear pleomorphism and mitotic figures (HE, original magnification x 200 and x 400, respectively); and D: chromogranin staining of the tumor cells demonstrating prominent chromogranin immunoreactivity (original magnification x 200).