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

Abstract

A 74−year−old Japanese man newly pres− ented with gastric polyposis, 2 years after intermittent administration of lornoxi− cam 12 mg (a new potent nonsteroidal anti−inflammatory drug) and nizatidine 300 mg daily (a histamine 2 −receptor an− tagonist) for knee joint pain and abdomi− nal discomfort, respectively. Gastroscopy (Figure 1 a, b) and double−contrast radio− graphy (Figure 1 c) showed multiple small hemispheric polyps circularly oriented in the gastric antrum, with tubular narrow− ing. 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 an− trum. In the hypoacidic conditions in− duced by a histamine 2 −receptor antago− nist, inflammatory polyps may arise in a rapid and excessive regenerative process after gastric mucosal injury due to NSAID administration.