Published online Jul 14, 2013. doi: 10.3748/wjg.v19.i26.4267
Revised: April 3, 2013
Accepted: April 10, 2013
Published online: July 14, 2013
A 57-year-old man underwent endoscopy for investigation of a duodenal polyp. Endoscopy revealed a hemispheric submucosal tumor, about 5 mm in diameter, in the anterior wall of the duodenal bulb. Endoscopic biopsy disclosed a neuroendocrine tumor histologically, therefore endoscopic mucosal resection was conducted. The tumor was effectively and evenly elevated after injection of a mixture of 0.2% hyaluronic acid and glycerol at a ratio of 1:1 into the submucosal layer. A small amount of indigo-carmine dye was also added for coloration of injection fluid. The lesion was completely resected en bloc with a snare after submucosal fluid injection. Immediately, muscle-fiber-like tissues were identified in the marginal area of the resected defect above the blue-colored layer, which suggested perforation. The defect was completely closed with a total of 9 endoclips, and no symptoms associated with peritonitis appeared thereafter. Histologically, the horizontal and vertical margins of the resected specimen were free of tumor and muscularis propria was also seen in the resected specimen. Generally, endoscopic mucosal resection is considered to be theoretically successful if the mucosal defect is colored blue. The blue layer in this case, however, had been created by unplanned injection into the subserosal rather than the submucosal layer.
Core tip: We herein report a case of endoscopic full-thickness resection of a duodenal neuroendocrine tumor after unplanned injection into the subserosal layer. Generally, large perforations require urgent salvage surgery and duodenal perforation is more serious than other sites of the gastrointestinal tract because of bile acid and pancreatic juice. In this case, we found the ‘‘mirror target sign’’ immediately, and repaired the defect endoscopically. Prompt recognition of this sign and rapid closing of the defect is important to minimize injury.