A case of appendiceal polyp detected by deflated lumen technique Adenomatous appendiceal polyps are rarely encountered during colonoscopy with an incidence of 0.004-0.08%. Appendeceal polyp could be missed because it is located in appendix lumen. The deflated lumen technique can aid to find the appendix polyp during colonoscopy. A 53-year-old male visited out hospital due to abdominal discomfort and dyspepsia. The laboratory test and upper endoscopy showed no specific finding. Colonoscopy was performed and multiple colon polyps were detected. During colonoscopy, no polyp was seen in the appendiceal orifice at initial view (Fig. A) but a 1.2cm sized pedunculated polyp was appeared when cecal lumen was deflated with air suctioning and disappeared after air inflation (Fig. B). We tried to remove appendiceal polyp by endoscopic polypectomy method however the procedure was stopped due to difficulty of snaring and risk of incomplete resection. The patient underwent laparoscopic cecectomy (Fig. C) and histopathologic finding was tubular adenoma without resection margin involvement (Fig. D). Subsequent colonoscopy at interval of 6 months showed no residual or recurrent lesions. The endoscopic removal of appendiceal polyps are reported in a few case reports. But endoscopic polypectomy of appendiceal polyp is not easy when the polyp is located in appendix lumen deeply. Therefore, surgical resection may be a better choice. We report an appendiceal polyp which was detected by deflated lumen technique and successfully removed by laparoscopic cecectomy.