Endoscopic submucosal dissection of multiple flat adenomas in the radiated rectum

Figure 1 An advanced neoplasm, 35 mm in size, in the rectum. A: Colonoscopy shows an ulcerative lesion in the rectum, the biopsy of which proved to be well differentiated adenocarcinoma; B: Chromoendoscopy with indigo carmine dye spray shows the lesion clearly.

Figure 2 A flat adenoma, 35 mm in size, in the anterior wall of the low rectum. A: The lesion was detected as a slight decline in vascular permeability on routine observation; B: Although we could highlight the irregular surface by spraying indigo carmine solution, it was difficult to trace the margin of the lesion; C, D: The surface structure of the lesion is composed mainly of IIIL pits with partially mixed IV pits on magnifying endoscopy with crystal violet staining; E: Figure A showing lesion borders without the aid of yellow lines; F: Figure B showing lesion borders without the aid of yellow lines; G: Magnifying endoscopy with crystal violet staining effectively delineates the margin of the lesion.

Figure 3 A slightly elevated adenoma, 10 mm in size, in the posterior wall of the low rectum. A: The lesion was detected with a slight decline in vascular permeability on routine observation; B: Although we could highlight the irregular surface by spraying indigo carmine solution, it was not possible to determine the area of the lesion; C: Regarding surface structure, the lesion is composed mainly of IIIL pits with partially mixed IV pits on magnifying endoscopy with crystal violet staining; D: Magnifying endoscopy with crystal violet staining effectively delineates the margin of the lesion; E: Figure A showing lesion borders without the aid of yellow lines; F: Figure B showing lesion borders without the aid of yellow lines; G: Figure C showing lesion borders without the aid of yellow lines; H: Figure D showing lesion borders without the aid of yellow lines.

Figure 4 Resected specimens. A: A complete one-piece resection of 52 mm × 30 mm in size with tumor-free margins was achieved; B: Complete one-piece resection with tumor-free margins 18 mm × 18 mm; C: Microscopy of the resected specimens revealed increased vessel wall thickness in the submucosal layer and the serous coat of the large intestine around the tumors, indicating chronic radiation proctitis; D: A well-differentiated adenocarcinoma, 35 mm × 18 mm, invading beyond the muscularis propriae (pT3). None of the 10 lymph nodes retrieved were involved (pN0). Moreover, adenomatous change, which endoscopic observation failed to detect, was found.