How to diagnose and manage gastric polyps with a minimal increase in lymphocytes in the lamina propria?

Diagnosis of Gastric Polyps with Minimal Lymphocytic Infiltration

Gastric polyps with minimal increase in lymphocytes in the lamina propria most likely represent fundic gland polyps (FGPs) or hyperplastic polyps, and diagnosis should be confirmed through biopsy when there are atypical features, with management determined by polyp size, location, and histologic characteristics. 1, 2

Diagnostic Approach

Initial Endoscopic Assessment

The diagnosis can often be made from endoscopic appearance alone for typical FGPs, which predict the diagnosis with high accuracy 1. However, biopsy confirmation is mandatory when atypical features are present, including:

• Size >1 cm 1, 2
• Antral or prepyloric location 1, 2
• Ulceration or irregular surface 1, 2
• Unusual appearance (redness, depression, pedunculated morphology) 1, 2

Histologic Interpretation of Lymphocytic Infiltration

A minimal increase in lymphocytes in the lamina propria is a non-specific finding that can be seen in several gastric polyp types 3, 4:

• Fundic gland polyps: Typically show minimal inflammation with preserved glandular architecture 1
• Hyperplastic polyps: Characterized by foveolar hyperplasia with variable inflammatory infiltrate in the lamina propria, including lymphocytes and plasma cells 2, 4
• Polypoid foveolar hyperplasia: A benign entity with minimal inflammation that must be distinguished from true hyperplastic polyps 5

The key distinction is that minimal lymphocytic infiltration alone does not indicate a specific diagnosis—the overall architectural pattern, glandular characteristics, and clinical context are essential 3, 4.

Size-Based Management Algorithm

Small Polyps (<1 cm)

• No intervention required for typical-appearing FGPs of this size, as the risk of dysplasia is extremely low 1
• For hyperplastic polyps <1 cm: Test for H. pylori and pursue eradication if positive, as regression occurs in up to 70% of cases 2
• Biopsy is not routinely necessary for typical small FGPs unless atypical features are present 1

Medium Polyps (1-3 cm)

• Complete resection is mandatory for all polyps >1 cm regardless of type 1, 2
• Larger FGPs (>1 cm) have been shown to be dysplastic in 1.9% and contain focal cancer in 1.9% 1
• For hyperplastic polyps in this size range, resection is required even if H. pylori eradication is planned, due to significant dysplasia risk (1.9-19%) 2

Large Polyps (>3 cm)

• Immediate resection is always recommended regardless of H. pylori status or presumed histology 2
• The risk of dysplasia and malignancy is high in this size category 2

Critical Diagnostic Workup

Essential Testing

• H. pylori testing in all cases, as hyperplastic polyps are associated with H. pylori gastritis in 25% of cases 2
• Careful evaluation of surrounding gastric mucosa for synchronous neoplasia, gastric atrophy, and intestinal metaplasia, as synchronous neoplastic lesions are present in approximately 6% of cases with dysplastic hyperplastic polyps 2, 5
• Multiple biopsies (ideally 6) from the polyp and surrounding mucosa to exclude patchy dysplasia 6, 2

Differential Diagnosis Considerations

The minimal lymphocytic infiltration pattern requires exclusion of:

• Gastric MALT lymphoma: Would show dense lymphoid infiltrate with lymphoepithelial lesions, not minimal infiltration 6
• Adenomatous polyps: Critical to exclude, as these have a 30% synchronous gastric adenocarcinoma rate and 50% contain cancer when >2 cm 2
• Juvenile polyps: Show hamartomatous features with dense stroma, cystic architecture, and prominent inflammatory infiltration—more than "minimal" 6, 7

Common Pitfalls to Avoid

• Do not assume all antral polyps are hyperplastic—the differential includes adenomatous polyps with high malignancy risk 2
• Do not delay resection of large polyps (>3 cm) for H. pylori eradication, as these must be resected immediately 2
• Do not overlook the surrounding gastric mucosa, as this determines surveillance strategy and may reveal synchronous neoplasia 2, 5
• Do not misinterpret polypoid foveolar hyperplasia as true hyperplastic polyps—the former has no malignant potential and requires no surveillance 5

Surveillance Strategy

• No surveillance is required for confirmed FGPs without dysplasia, except in familial adenomatous polyposis (FAP) patients 1
• Surveillance intervals should be determined by the stage of chronic atrophic gastritis in the background mucosa rather than the polyp itself 2, 5
• Endoscopic surveillance is recommended when there is evidence of dysplasia, gastric atrophy, or intestinal metaplasia 2

PPI Considerations

FGPs are strongly associated with long-term PPI use and can spontaneously regress when PPIs are stopped 1. Re-evaluate PPI appropriateness in all patients with FGPs, as discontinuation may lead to polyp regression 1.