A Japanese woman presented with gastric antral ulcers accompanied by erosion and edema, demonstrating a chronic pattern of improvement and recurrence for more than six years. The patient had no relevant treatment history, and Helicobacter pylori infection was ruled out. Other potential etiologies contributing to gastric ulcers were eliminated on the basis of endoscopic biopsy and blood laboratory findings. Consequently, the patient was diagnosed with idiopathic gastric antral ulcer. This disease is often overlooked, and the chronological endoscopic images provided in this report can be used as a reference.

Several features of drug-induced mucosal alterations have been observed in the upper gastrointestinal tract, i.e., the esophagus, stomach, and duodenum. These include pill-induced esophagitis, desquamative esophagitis, worsening of gastroesophageal reflux, chemotherapy-induced esophagitis, proton pump inhibitor-induced gastric mucosal changes, medication-induced gastric erosions and ulcers, pseudomelanosis of the stomach, olmesartan-related gastric mucosal inflammation, lanthanum deposition in the stomach, zinc acetate hydrate tablet-induced gastric ulcer, immune-related adverse event gastritis, olmesartan-asso-ciated sprue-like enteropathy, pseudomelanosis of the duodenum, and lanthanum deposition in the duodenum. For endoscopists, acquiring accurate knowledge regarding these diverse drug-induced mucosal alterations is crucial not only for the correct diagnosis of these lesions but also for differential diag-nosis of other conditions. This minireview aims to provide essential information on drug-induced mucosal alterations observed on esophagogastroduodenoscopy, along with representative endoscopic images.

A 65-year-old Japanese woman underwent umbilical cord blood transplantation for acute myeloid leukemia. Zinc acetate dihydrate tablets were administered for hypozincemia after transplantation, and vomiting and appetite loss occurred soon thereafter. Esophagogastroduodenoscopy revealed mucosal redness, erosion, white coat adhesion, and ulcers. Although graft-versus-host disease, intestinal transplant-associated microangiopathy, and cytomegalovirus infection were considered as possible causes, we diagnosed the patient with zinc acetate dihydrate tablet-associated gastric mucosal alterations based on the endoscopic features. This case reinforces the notion that medication-associated gastric lesions should be suspected in patients taking zinc acetate dihydrate tablets.