Prevalence and Clinicopathological Features of Autoimmune Metaplastic Atrophic Gastritis in the Eastern Province of Saudi Arabia: A Regional Study.

Introduction. Autoimmune metaplastic atrophic gastritis (AMAG, also termed autoimmune gastritis) is a chronic gastritis of autoimmune pathogenesis. Although its clinical and pathological features are well-documented in many countries, data from Middle Eastern populations remain scarce. This study examined the prevalence of AMAG in gastric specimens from the region, specifically from Saudi Arabia. Methods. We conducted a retrospective review of the pathology database of gastric specimens with a diagnosis of AMAG between 2020 and 2023. Detailed clinical, endoscopic, and pathological features of identified features were described. Result. Of the 978 gastric biopsies received, 17 patients were diagnosed with AMAG. The cohort comprised 11 women (64.7%) and 6 men (35.3%), presenting at a median age of 50 years (range: 32-85). Clinical manifestations varied widely, from abdominal pain (n = 6), dyspepsia (n = 2), symptomatic anemia with significant vitamin B12 deficiency (2 of 17) to asymptomatic/incidentally diagnosed patients (5 of 17). The tissue samples showed varying histological characteristics, with some showing lymphoplasmacytic infiltrate, mucosal atrophy, and hyperplasia of enterochromaffin-like cells. Conclusion. The observed prevalence of AMAG in our study aligns with global averages reported for other populations. The diverse clinical presentations highlight the need for awareness of findings in AMAG in gastric biopsies to ensure appropriate clinical management.