Rectal Carcinoid: Effectiveness of Endoscopic Resection

ABSTRACT

PURPOSE: Small-sized carcinoids, less than 1 cm, are easily detected using flexible sigmoidoscopy or total colonoscopy and can be treated by local excision. Recently, there has been many advances in the technique of endoscopic resection. The aim of this study was to determine the endoscopic findings of a rectal carcinoid and to evaluate the effectiveness of endoscopic resection. METHODS: We experienced 22 rectal carcinoids in 21 patients who were treated by endoscopic resection from June 1996 to February 1999. Nineteen cases were followed for an average of 21 months. Follow-up studies consisted of chest P-A, hepatic ultrasonography, and total colonoscopy. RESULTS: The male-to-female ratio was 1.6 to 1. The most common age group was the 4th decade. The tumor was located at the lower rectum in 10 patients, at the upper rectum in 10 patients, and at the rectosigmoid junction in 2 patients. The tumor sizes ranged from 3 to 12 mm in diameter and were smaller than 10 mm in 20 cases (90.1%). Endoscopic finding revealed that the tumors were covered by a normally appearing mucosa in 12 cases, were yellow-discolored polyps in 17 cases, and were sessile-type tumors in 19 cases. The method of treatment was an endoscopic mucosal resection (EMR, 14 cases) or a snare polypectomy (8 cases). Microscopically positive margins were noticed in four cases, two cases of EMR (2/14, 14%) and two cases of snare polypectomy (2/8, 25%). All the patients were alive and clinically free of disease; however, the duration of the follow-up is short. CONCLUSIONS: Endoscopic resection for rectal carcinoid tumors smaller than 1 cm in diameter is a safe, functional, time-saving, and effective treatment. If the tumor suggests a carcinoid, EMR is advised rather than a polypectomy even though the tumor is small. Microscopically positive margins are not absolute indications for further surgery in the treatment of carcinoids smaller than 1 cm in diameter. It is much more important for an endoscopist to be confident that the endoscopic resection is done completely. It is necessary to identify the factors influencing the malignancy potential and to have a longer follow-up.