Unusual gastric polyp showing submucosal proliferation of glands: Case report and literature review

Abstract

We report an unusual pedunculated polyp in the stomach in a 41-year-old woman. She was hospitalized because of epigastric discomfort. Endoscopy revealed a polyp with a long stalk in the fundus of the stomach. The polypectomyzed polyp measured 23 x 18 x 9 mm and was characterized by submucosal proliferation of glands and cystic dilatation. The surface of the polyp was covered with gastric mucosa of fundic or pyloric gland type. The glandular structures consisted of various types of lining cells, including pyloric or mucous-neck cell type, surface mucous (foveolar) cell type, parietal-like cells, and somatostatin-positive cells. The submucosal glandular or cystic elements were connected with the overlying gastric mucosa through a defect of the muscularis mucosa, suggesting that this polyp may have been formed by the heterotopic inverted downgrowth of mucous glands into the submucosa. We discuss the histogenesis of this rare polyp and present a review of the literature.

Multifocal Adenocarcinomas Arising within a Gastric Inverted Hyperplastic Polyp

“…To date, 35 cases of gastric IHP, including the present case, have been described in the English-language literature. Although the pathogenesis of IHP is not understood, studies suggest that inflammation and subsequent healing may promote the epithelial displacement 4,5. In our patient, the connection between the inflamed overlying mucosa and the hyperplastic component, and the presence of the slit-shaped cavity in the center suggested that repeated mucosal inflammation caused a break in the muscularis mucosae, which permitted the downward herniation and submucosal trapping of mucosal glands.…”

A case of gastric hamartomatous inverted polyp resected endoscopically

“…GHIPs are characterized pathologically by cystic, dilated, hypertrophic pseudopyloric gland proliferation and by smooth-muscle fibers located in the submucosal layer, with branching from the proliferation of smooth-muscle bundles. The main lesion in GHIP is located in the submucosa or within the muscularis mucosae 3.…”

Two rare gastric hamartomatous inverted polyp cases suggest the pathogenesis of growth

“…GHPs are pathologically defined by cystic dilated hypertrophic pseudo-pylorus gland proliferation and smooth muscle located in the submucosal layer with branching from the proliferation of smooth muscle bundles [7] . Although Peutz-Jeghers syndrome, juvenile polyposis and Cowden disease are hereditary, it is rare to encounter 2 cases of monostotic and asymptomatic gastric hamartomas [8][9][10][11][12] .…”