Gastric Polyps and Thickened Gastric Folds

Fundic Gland Polyps

The most common gastric polyp encountered during upper endoscopy is the FGP ( Fig. 30.1 ), which account for greater than 70% of all polyps identified during upper endoscopy and have a prevalence of 3% in the general population. FGPs are generally incidentally identified and are most often asymptomatic in patients. FGPs may occur as single or multiple epithelial lesions often clustered with a grape-like appearance. They are predominantly located in the gastric fundus or proximal body of the stomach, and are generally small, varying from 1 mm to occasionally up to 2 cm.

Endoscopic appearance is generally suggestive of these lesions with bland overlying glistening mucosa of pale color; however, diagnosis of these lesions is confirmed by histology after biopsy or removal of representative lesions. Histology reveals the classic appearance of dilated oxyntic glands with flattened parietal cells forming a microcystic appearance.

The pathogenesis of FGPs is unknown. Sporadic FGPs are more commonly seen in women than in men. They may be frequently seen in conjunction with Helicobacter pylori ( H. pylori ) infection. FGPs have been thought to occur more frequently in patients taking proton pump inhibitors (PPIs), though a causal relationship has not been demonstrated. A 2016 meta-analysis of 12 papers found an increased odds ratio of PPI use with the development of FGPs. Overall, sporadic FGPs are benign entities with no clinical consequence.

Multiple FGPs are seen in association with familial adenomatous polyposis (FAP) syndrome ( Fig. 30.2 ). Patients with FAP will have hundreds to thousands of FGPs in the gastric fundus and body, and may have no such polyps in the antrum. In patients with FAP, FGPs have a similar benign natural history, but there are reports of conversion of benign FGPs to dysplastic lesions in as many as up to 40% of cases.

For patients without FAP, FGPs usually require no intervention. Biopsies on initial endoscopy to confirm the diagnoses are standard. Once diagnosed as FGPs, no surveillance is recommended; however, because of the risk of neoplastic transformation, surveillance with biopsies of these lesions in FAP patients is recommended.

Hyperplastic Polyps

Hyperplastic polyps are the second most common type of polyps encountered in routine upper endoscopy ( Fig. 30.3 ). These polyps are generally felt to be benign; however, several series have identified the presence of dysplasia (0.2% to 10%) or adenocarcinoma (0.6% to 3%) within these lesions. Endoscopically, hyperplastic polyps have a wide range of appearances. There may be one or multiple. They can arise in any part of the stomach. They may be small, starting at a few millimeters in size, to large, mimicking the appearance of carcinoma. They may be sessile or pedunculated. The overlying mucosa may appear normal or may appear erythematous and with patches of exudate as the size increases.

Hyperplastic polyps have been associated with H. pylori gastritis and chronic gastritis, noted in association with autoimmune or atrophic gastritis with pernicious anemia. Histology reveals submucosal edema, prominent foveolar hyperplasia, and inflammation of the lamina propria.

The approach to endoscopic management of hyperplastic polyps is debated. Biopsy of representative lesions to establish the diagnosis is recommended. Removal of polyps is generally individualized based on the size, appearance, histology, and clinical presentation. Some authors advocate for removal of all hyperplastic polyps above 5 mm because of the potential for development of dysplasia. Generally, though, authors believe the risk of malignant transformation is low. Thus, large polyps should be sampled or removed depending on safety and feasibility of doing so. Bleeding polyps or those thought to be contributing to symptomatic anemia should be considered for polypectomy. Whether surveillance endoscopy should be performed after biopsy of hyperplastic polyps is also unclear. In our practice, hyperplastic polyps are not generally surveyed unless dysplasia has been established on first endoscopy. The presence of H. pylori should also be assessed and treated as this has been associated with reduced polyp recurrence and reduced progression to cancer.