Figure legends
Figure. 1. Preoperative findings
a, b: Colonoscopy showing a mass lesion approximately 2 cm in diameter at the lower rectum (a: Looking up image, b: Front image). The degree of lesion invasion on endoscopic evaluation suggested infiltration into the deep submucosal layer. c: Radiographic contrast enema image showing that the lower edge of the lesion was approximately 3 cm away from the dentate line (the lesion is in the area of the yellow arrows indicated the location of the lesion).