From pre-tumor to tumor: Decoding the endoscopic-pathologic spectrum of neoplastic lesions in autoimmune gastritis.

Autoimmune gastritis (AIG) is a chronic atrophic gastritis predisposing to neuroendocrine tumors (NETs), dysplasia, and gastric cancer (GC). In a cohort of 1,551 patients with suspected AIG, we identified 46 with neoplastic lesions and 134 without such lesions and compared their clinicopathological and endoscopic features. NETs typically appeared as polypoid/submucosal tumors with dilated vessels or central depression; epithelial neoplasms showed variable morphologies, with irregular microvessels under narrow-band imaging (NBI). Extensive corpus atrophy and antral patchy redness were independent risk factors for AIG-associated neoplasia, whereas female sex was protective. These findings support a risk model integrating clinical, endoscopic, and pathological features for individualized surveillance.