A Benign Appendiceal-Colonic Fistula, Diagnosed and Managed Laparoscopically: A Case Report

BACKGROUND Treatment methods for appendiceal-colonic fistulas differ greatly depending on whether lesions are benign or malignant. If the tumor is malignant, appendectomy with lymph node resection (ileocecal resection or right hemicolectomy) should be performed. There is no consensus on the method of surgery for organs infiltrated by appendiceal cancer. Furthermore, there are no reported laparoscopic cases that could be prevented from over-surgery by laparoscopy examination or rapid intraoperative pathological examination. CASE REPORT A 76-year-old man presented with positive fecal occult blood. Lower endoscopy revealed a 10-mm tumor in the rectosigmoid colon accompanied by white moss. A biopsy showed inflammatory granulation and no malignancy. Fluorodeoxyglucose-positron emission tomography showed highly increased accumulation at the tip of the appendix, and the standardized uptake value max was 7.3. We suspected a benign lesion rather than appendiceal cancer with infiltration into the rectosigmoid colon; therefore, we performed laparoscopic appendectomy and wedge-shaped resection of the rectum of the sigmoid colon. An intraoperative rapid pathological examination showed no appearance of malignancy; therefore, additional resection was omitted, and an ileostomy was created in the right lower quadrant. A permanent pathological examination showed complicated appendicitis, with no appearance of malignancy. The ileostomy was closed on postoperative day 25, and the patient was discharged on postoperative day 32. CONCLUSIONS In cases where there is difficulty in identifying whether the appendiceal-colonic fistula lesion is benign or malignant, laparoscopy and intraoperative rapid pathological examination may be useful in avoiding excessive treatment.