Conservative treatment of phlegmonous gastritis that developed after gastric endoscopic submucosal dissection: A case report

A 91-year-old woman underwent gastric endoscopic submucosal dissection (ESD) for early gastric cancer. On the following morning, she complained of upper abdominal pain and fever, and inflammatory response markers were elevated in blood biochemistry tests. Computed tomography revealed no signs of pneumonia or free air, but the gastric wall was severely thickened. Esophagogastroduodenoscopy revealed diffuse edematous changes of the mucosa of the gastric corpus. A diagnosis of acute phlegmonous gastritis was made, and Tazobactam/Piperacillin administration was immediately initiated, after which her symptoms rapidly improved. Phlegmonous gastritis after gastric ESD is a rare but serious incidental condition that requires early diagnosis by diagnostic imaging and appropriate administration of sufficient doses of antibiotics.