Endoscopic ultrasonography features of gastric mucosal cobblestone-like changes from a proton-pump inhibitor

A 68-year-old man with no symptoms presented to Hokkaido University Hospital for esophagogastroduodenoscopy screening. He had a history of Helicobacter pylori eradication. Initial esophagogastroduodenoscopy showed no gastric cobblestone-like mucosa or gastric cracked mucosa. After 1 year, he received esomeprazole (20 mg) once daily for heartburn at another hospital. Esophagogastroduodenoscopy was performed after 2 years of esomeprazole administration. Endoscopic findings showed that after H. pylori eradication, according to the Kyoto classification, gastric cobblestone-like mucosa presented in the gastric body area. Dilation of the oval crypt opening and intervening part in the gastric cobblestone-like mucosa was detected by endoscopy with narrow band imaging. Endoscopic ultrasonography revealed a thick gastric second layer and sporadic small a-echoic lesions in the low-echoic thickened second layer in the gastric cobblestone-like mucosa. The gastric cobblestone-like mucosa biopsy specimen showed parietal cell protrusions and oxyntic gland dilatations. Recently, we reported that gastric mucosal changes such as gastric cracked mucosa and gastric cobblestone-like mucosa were caused by proton-pump inhibitors; however, the gastric cobblestone-like mucosa was not examined by endoscopic ultrasonography. In this case, endoscopic ultrasonography findings suggested that oxyntic gland dilatations caused the elevated gastric mucosa, such as gastric cobblestone-like mucosa, from the use of proton-pump inhibitors.