What does gastric antral filiform hyperplasia indicate and what is the recommended evaluation and management?

Gastric Antral Filiform Hyperplasia: Clinical Significance and Management

What It Indicates

Gastric antral filiform hyperplasia represents a reactive inflammatory process that signals underlying chronic gastritis, most commonly from H. pylori infection (present in 25% of cases), and is associated with gastric atrophy and intestinal metaplasia—conditions that increase gastric cancer risk. 1

The presence of filiform hyperplasia in the antrum specifically indicates:

• Chronic mucosal injury and repair mechanisms are active, as these polyps almost never occur in normal gastric mucosa and arise as a by-product of repair to damaged tissue 2
• Potential for dysplasia exists, with hyperplastic polyps harboring dysplasia in 1.9-19% of cases and malignant transformation occurring especially when polyps exceed 1 cm 1, 3
• Synchronous neoplasia risk of approximately 6% when dysplasia is present in the polyp itself, mandating careful evaluation of the surrounding gastric mucosa 1, 3

Recommended Evaluation Algorithm

Initial Endoscopic Assessment

• Document polyp characteristics: number, size (measure precisely), location, morphology (sessile vs pedunculated), and presence of erosions or ulceration 1, 4
• Obtain histologic confirmation through biopsy to verify the diagnosis is hyperplastic and exclude dysplasia, as clinical appearance alone is insufficient 1, 3
• Systematically evaluate the entire stomach for synchronous neoplastic lesions, degree and extent of gastric atrophy, and intestinal metaplasia—not just the polyp itself 1, 3, 4

Mandatory Testing

• Test for H. pylori infection in all cases using biopsy-based methods, as 25% of hyperplastic polyps are associated with H. pylori gastritis and up to 70% will regress after eradication 1, 3
• Assess background mucosa for gastric atrophy and intestinal metaplasia, as these determine long-term surveillance needs independent of the polyp 1, 3

Optical Enhancement (When Available)

• Use NBI, i-Scan, or FICE to characterize polyps, as hyperplastic polyps display prolonged or villous pits with a dense vascular pattern (sensitivity 93.6%, specificity 91.6%) 1, 4

Management Strategy Based on Size

Small Polyps (<1 cm)

• Eradicate H. pylori first if infection is present, then perform repeat endoscopy 3-6 months after eradication to assess for regression 1, 3
• Do not resect immediately unless symptomatic (bleeding, obstruction), as up to 70% will regress with H. pylori treatment alone 1, 3

Medium Polyps (1-3 cm)

• Complete endoscopic resection is mandatory for all polyps >1 cm, pedunculated morphology, or symptomatic polyps regardless of H. pylori status, due to significant dysplasia risk (1.9-19%) 1, 3, 4
• Consider H. pylori eradication before resection for polyps 1-3 cm to potentially reduce polyp burden, but do not delay resection beyond 3-6 months 1, 3

Large Polyps (>3 cm)

• Immediate resection is always required regardless of H. pylori status, as the risk of dysplasia and cancer is high 1, 3
• Do not attempt H. pylori eradication first for polyps >3 cm—proceed directly to resection 1, 3

Post-Resection Surveillance

• Endoscopic surveillance is required when dysplasia, gastric atrophy, or intestinal metaplasia is present 1, 3, 4
• Surveillance intervals are determined by the stage of chronic atrophic gastritis, not by the polyp itself 1, 3
• Perform follow-up endoscopy at 6-12 months after resection when dysplasia was present in the polyp 4

Critical Pitfalls to Avoid

Misdiagnosis Risk

• Never assume all antral polyps are hyperplastic without histologic confirmation, as adenomatous polyps have a 30% synchronous gastric adenocarcinoma rate and 50% contain cancer when >2 cm 3, 4
• Distinguish from gastric mucosal prolapse polyps, which account for 31% of lesions originally diagnosed as hyperplastic polyps and have different pathophysiology (basal glandular elements, hypertrophic muscle fibers, thick-walled vessels) 5

Management Errors

• Do not delay resection of large polyps (>3 cm) for H. pylori eradication attempts, as immediate resection is mandatory due to high malignancy risk 1, 3
• Do not focus solely on the polyp—failure to evaluate surrounding mucosa misses synchronous neoplasia in 6% of cases with dysplastic hyperplastic polyps 1, 3
• Do not assume benignity based on size alone—even polyps <1 cm can harbor dysplasia, though the risk is lower 3, 4

Surveillance Gaps

• Do not discharge patients after polyp removal if gastric atrophy or intestinal metaplasia is present, as these require ongoing surveillance regardless of polyp removal 1, 3
• Do not use fixed surveillance intervals—tailor intervals to the stage of chronic atrophic gastritis present in the background mucosa 1, 3