Autoimmune Metaplastic Atrophic Gastritis in a Filipino Patient: A Case Report

Abstract

Background: Autoimmune metaplastic atrophic gastritis (AMAG) is a chronic, progressive inflammatory disease that affects roughly 0.1 percent of the general population and 2% of those over the age of 60. Pernicious anemia, atrophic gastritis, antibodies to parietal cell antigens and intrinsic factor, achlorhydria, and hypergastrinemia are all common findings in this disease. In addition, it is a major risk factor for stomach neoplasia.

Methodology: We have a 44/F with no known comorbids who came in due to epigastric pain. One week prior to admission patient noted intermittent epigastric pain, burning and sharp in character, nonradiating lasting for 1 to 2 hours, aggravated by food intake. This was associated with episodes of regurgitation and occasional post-prandial vomiting and dizziness. On physical examination, she had pale palpebrae conjunctivae and abdominal examination revealed direct epigastric tenderness with no guarding or rigidity.

Results: Laboratories done showed megaloblastic anemia with low Vitamin B 12 levels and positive Fecal Immunochemical Test.Esophagogastroduodenoscopy revealed pale gastric mucosa and absentrugal folds.Colonoscopy showed normal terminal ileumand internal hemorrhoids grade 1. Multiple biopsies takenfrom the corpus revealed gastric fundic type mucosa with moderate chronic inflammation, mild intestinal metaplasia and severe atrophyand absentHelicobacter pyloriorganism. Histopathologic samples stained positive for immunohistochemical stains, chromogranin and synaptophysin. Further laboratories done also showed elevated serum gastrin. She was then discharged and started on lifelong parenteral Vitamin B12 supplementation.

Conclusion: AMAG is a rare disease entity. It should be suspected in patients with anemia and Vitamin B 12 deficiencey. Prompt recognition is important as it is a risk factor for gastric cancer and carcinoid tumors as well as preventing longterm complications of Vitamin B12 deficiency.