Abstract
Vonoprazan-associated gastric mucosal redness is rare, and its endoscopic and pathological features remain poorly described. We report 4 cases of vonoprazan-associated gastric mucosal redness, that is, 2 cases each in non-Helicobacter pylori-infected and -eradicated stomach. In all cases, esophagogastroduodenoscopy demonstrated spotty and linear redness newly appearing in the greater curvature of the gastric body after initiation of vonoprazan but disappearing after its discontinuation. A tissue biopsy taken from the gastric mucosa with redness revealed various pathological findings and included inflammatory cell infiltration, parietal cell protrusions, oxyntic gland dilatations, congestion, focal hemorrhage with congestion beneath the basement membrane, and vacuolar degeneration of parietal cells. To our knowledge, this is the second report describing the endoscopic and pathological features of vonoprazan-associated gastric mucosal redness.