Single tunnel-assisted endoscopic submucosal dissection for a 13-cm giant colorectal laterally spreading tumor.

We report the case of a 60-year-old male with a giant colorectal laterally spreading tumor at the recto-sigmoid junction. A single tunnel-assisted endoscopic submucosal dissection was performed that constructed a submucosal tunnel along the longitude axis of the tumor. An en bloc resection was achieved with no perforation or post-operative bleeding and a comparatively low procedure time.