Work

Reconsidering the Mechanism of Proton Pump Inhibitor‐Associated Fundic Gland Polyps: Absence of Re‐enlargement during Potassium‐Competitive Acid Blocker Therapy

Year: 2026

Type: article

Abstract: Fundic gland polyps (FGPs) may enlarge during long-term proton pump inhibitor (PPI) therapy, potentially in association with acid suppression and hypergastrinemia. Potassium-competitive acid blockers (PCABs) provide potent and sustained acid suppression and may induce comparable or greater elevations in serum gastrin levels than PPIs. We report a case of FGPs in which regression was documented after changes in acid-suppressive therapy, with no subsequent re-enlargement during long-term use of PCABs. A woman in her 60s with gastroesophageal reflux disease developed progressive enlargement of FGPs during 7 years of rabeprazole therapy. Rabeprazole was discontinued because of marked redness of the enlarged FGPs and concern for possible bleeding and was replaced with an H2-receptor antagonist. After reintroduction of rabeprazole, treatment was switched to a PCAB because of insufficient symptom control. Four months after PCAB initiation, esophagogastroduodenoscopy demonstrated marked regression of the FGPs, with no subsequent re-enlargement during continued PCAB therapy. Serum gastrin levels were elevated at both measurements during PCAB use (491.9 and 753.7 pg/mL). Histological examination revealed similar fundic gland changes characteristic of FGPs in both a residual polyp and the endoscopically non-polypoid background mucosa, without dysplasia. Because the exact timing of FGP regression could not be determined, the regression observed 4 months after vonoprazan initiation cannot be solely attributed to vonoprazan therapy and may have occurred, at least in part, during the preceding period of PPI discontinuation. Nevertheless, no subsequent re-enlargement was observed during long-term vonoprazan therapy. Clinical Trial Registration: Clinical trial registration was not applicable because this was a single case report.

Source: DEN Open

DOI: 10.1002/deo2.70463

Authors: Yoshitsugu Misumi, Tatsuyuki Marumo, Shinichi Ban, Kouichi Nonaka

Institutions: Tokyo Women's Medical University Hospital, Tokyo Women's Medical University, Saitama Prefectural Hospital Organization, Dokkyo Medical University Saitama Medical Center

Language: English

Topic: Gastroesophageal reflux and treatments

Subfield: Gastroenterology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,500