title: Unexpected endoscopic full-thickness resection of a duodenal neuroendocrine tumor.
abstract: 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.
authors.affiliation: Division of Digestive Endoscopy, Department of Gastroenterology, National Cancer Center Hospital East, Kashiwa City, Chiba 277-8577, Japan. kn_hatogai@hotmail.com
authors.forename: Ken
authors.initials: K
authors.lastname: Hatogai
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Oono
authors.forename: Kuang-I
authors.initials: KI
authors.lastname: Fu
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Odagaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ikematsu
authors.forename: Takashi
authors.initials: T
authors.lastname: Kojima
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yano
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D001706:Biopsy; D004379:Duodenal Neoplasms / Q000473:pathology / Q000601:surgery*; D004384:Duodenoscopy; D006801:Humans; D007417:Intestinal Polyps / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology / Q000601:surgery*; D011237:Predictive Value of Tests; D016896:Treatment Outcome
keywords: Duodenum; Endoclip; Endoscopic mucosal resection; Hyaluronic acid; Neuroendocrine tumor; Perforation; Submucosal tumor