A 76-year-old woman was referred to the National Cancer Center Hospital for treatment of a large laterally spreading tumor (granular-type) of the rectum (●" Fig.1a). The lesion was >10cm in diameter. There were no endoscopic findings suggesting submucosal invasion, and therefore endoscopic submucosal dissection (ESD) was chosen as radical treatment. The ESD procedure was performed, and a en bloc resection was achieved (●" Fig.1b,c). Following the ESD procedure, attempts were made to remove the specimen through the anal canal using a retrieval device (Roth Net; Olympus Co., Tokyo, Japan). However, this approach failed because of the size of the tumor. It was therefore decided to use a sliding overtube (ST-C5; Olympus Co., Tokyo, Japan) to remove the specimen from the rectum (●" Fig.2). To obtain maximal suction effect, one end of the overtube was packed using a surgical glove (●" Fig.2b). The colonoscope was withdrawn, and the overtube was fitted to the colonoscope. After visualizing the specimen, the overtube was carefully inserted into the rectum. Then the colonoscope was pulled out and back into the sliding tube repeatedly. Under direct visualization the specimen was vacuumed up into the sliding tube, and the sliding tube was removed from the rectum (●" Video 1). The resected specimen was 135mm long and 105mm wide (●" Fig.3). Fig.1 Endoscopic submucosal dissection (ESD) of a large laterally spreading tumor (granular-type) of the rectum. a Colonoscopy revealed the tumor. b,c The ESD procedure was performed using a B-knife (Zeon Medical Co., Tokyo, Japan) and an IT knife (Olympus Co., Tokyo, Japan).