Fig. 3

Histopathological view of the resected specimen near the site of endoclip attachment. a HE-stained weakly magnified image revealed thickening of the mucosa and hyperplasia of the crypt epithelium. b Magnified image of the blue square showed pseudopyloric gland proliferation with cystic dilation in the mucosa. The muscularis mucosa was entangled and elevated radially. c Magnified image of the red square showed mucosal damage such as fibrin exudation along with necrosis. No atypical cells were found in the resected specimen. d–f Histopathological views of the serial resected specimens including the section shown in (a). Elastica van Gieson-stained weakly magnified images showed muscular vessels that developed between muscularis and submucosa. g, h Magnified images of the yellow and green squares showed muscular vessels with an irregularly thickened lumen (arrows). Such lumen was occluded by fibrous tissue (arrowhead)