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

Abstract

Aim: Rectal carcinoid tumors smaller than 10 mm can be resected with local excision using endoscopy. In order to remove rectal carcinoid tumors completely, we evaluated endoscopic mucosal resection with a ligation device in this pilot control randomized study.

Methods: Fifteen patients were diagnosed with rectal carcinoid tumor (less than 10 mm) in our hospital from 1993 to 2002. There were 9 males and 6 females, with a mean age 61.5 years (range, 34-77 years). The patients had no complaints of carcinoid syndrome symptoms. Fifteen patients were randomly divided into 2 groups: 7 carcinoid tumors were treated by conventional endoscopic resection, and 8 carcinoid tumors were treated by endoscopic resection using a ligation device.

Results: All rectal carcinoid tumors were located at the middle to distal rectum. The size of the tumors varied from 3 mm to 10 mm and background characteristics of the patients were not different in the two groups. The rate of complete removal of carcinoid tumors using a ligation device (100%, 8/8) was significantly higher than that of conventional endoscopic resection (57.1%, 4/7). The three patients had tumor involvement of deep margin, for which additional treatment was performed. No complications occurred during or after endoscopic resection using a ligation device. All patients in the both groups were alive during the 3-year observation period.

Conclusion: Endoscopic resection using a ligation device is a useful and safe method for resection of small 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).