S5337 Polyp Implantation at Traction Site During Endoscopic Submucosal Dissection for Large Colonic Polyp Resulting in Subsequent Recurrence: A Case for Ongoing Vigilance

Introduction: Endoscopic submucosal dissection (ESD) is a technically complex method for removal of large non-pedunculated colorectal polyps and has a significantly lower recurrence rate than endoscopic mucosal resection. We present a case of a patient who underwent successful ESD with opposite wall traction for a large lateral spreading ascending colon polyp, but was later found to have multiple small polyps distal to the resection site, raising concern for satellite lesions at traction site. Case Description: A 53-year-old woman with a family history of colorectal cancer in maternal aunt and grandmother underwent surveillance colonoscopy. A large laterally spreading adenomatous polyp was seen in the ascending colon. The patient was referred for advanced endoscopic resection and the decision was made to proceed with endoscopic submucosal dissection. Repeat colonoscopy revealed a large (>50 mm) polyp extending from the cecum into the ascending colon, located opposite the ileocecal valve. Careful inspection of ascending colon did not show any other lesions. ESD was successfully performed using clip traction with 2 hemostatic clips and orthodontic rubber band. Pathology showed a 54 mm tubular adenoma with focally extending to lateral margin. At 1-year follow-up colonoscopy, a scar was observed in the proximal ascending colon at site of prior endoscopic submucosal dissection. Distal to this site on opposite wall 7 small sub centimeter polyps were seen. These polyps were removed with cold snare and pathology showed tubular adenomas. Discussion: Endoscopic submucosal dissection (ESD) is an advanced and technically demanding technique that enables en bloc resection of large lesions, with reported local recurrence rates as low as 0.9%-2%. Perforations that occur in an area of malignancy during ESD have been reported to cause peritoneal seeding of malignancy. Tumor cell implantation within intestinal lumen has also been reported at distal endoscopic mucosal resection site, proximal location due to specimen retrieval. Metachronous lesions have also been reported due to biopsy or tattoo resulting in contamination of working channel of endoscope. While limited literature exists regarding polyp seeding during endoscopic resection, we believe this is first reported case of satellite lesions forming at site of traction due to contact of polyp with opposite wall during endoscopic submucosal dissection.