A Case of Oxyntic Gland Neoplasm Incidentally Found During Upper Endoscopic Screening

Oxyntic gland neoplasms (OGNs) are rare gastric epithelial tumors characterized by primary differentiation into chief cells and, to a lesser extent, parietal cells. It includes oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type (GA-FG) depending on the depth of invasion. Although generally indolent, another subgroup, GA-FG mucosa type, may exhibit more invasive behavior. We report a case of an asymptomatic 57-year-old man in whom a small, slightly elevated hyperemic lesion was incidentally found on surveillance endoscopy. Endoscopic mucosal resection using the cap-assisted method (EMR-C) was performed following a biopsy, which suggested a fundic gland-type neoplasm. Histopathologic evaluation confirmed GA-FG with submucosal invasion, but no lymphovascular invasion (pT1b). Post-EMR CT and follow-up endoscopy revealed no evidence of recurrence or metastasis. Recognition of OGNs require histopathologic and immunohistochemical confirmation using markers such as MUC-5AC and MUC-6. In most cases, complete endoscopic resection is curative. Further studies with larger cohorts and long-term follow-ups are needed in order to clarify the natural course and optimal management of this rare neoplasm.