Gastric Inflammatory Polyposis after Long-Term Intermittent Use of Nonsteroidal Anti-Inflammatory Drugs and Histamine₂-Receptor Antagonists

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A 74-year-old Japanese man newly presented with gastric polyposis, 2 years after intermittent administration of lornoxicam 12 mg (a new potent nonsteroidal anti-inflammatory drug) and nizatidine 300 mg daily (a histamine₂-receptor antagonist) for knee joint pain and abdominal discomfort, respectively. Gastroscopy (Figure [1] a, b) and double-contrast radiography (Figure [1] c) showed multiple small hemispheric polyps circularly oriented in the gastric antrum, with tubular narrowing. On histology, the polyps were found to consist of inflamed granulation tissue, with immature regenerative epithelium (Figure [1] d).

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a well-known cause of acute gastric mucosal lesions, characterized by multiple shallow ulcers in the gastric antrum. In the hypoacidic conditions induced by a histamine₂-receptor antagonist, inflammatory polyps may arise in a rapid and excessive regenerative process after gastric mucosal injury due to NSAID administration.

Figure 1 Gastroscopy (a, b) and double-contrast radiography (c), showing multiple small hemispheric polyps circularly oriented in the gastric antrum, with tubular narrowing. d On histology, the polyps were found to consist of inflamed granulation tissue, with immature regenerative epithelium.

Endoscopy_UCTN_Code_CCL_1AB_2AD_3AB