Chronic atrophic gastritis - An overlooked association with severe vitamin B12 deficiency: A case report and rapid review of literature.

The current guidelines recommend surveillance for gastric adenocarcinoma in patients with extensive chronic atrophic gastritis (CAG), which is considered a premalignant condition. A 65-year-old female patient with new onset sensory symptoms was found to have severe vitamin B12 deficiency. She had a normal immunology screen, with negative parietal cell and intrinsic factor antibody titres. Gastroscopy revealed areas of gastric atrophy which was confirmed on biopsy. There was no evidence of Helicobacter pylori in the biopsies. Although the association between vitamin B12 deficiency and CAG is well described, the indication for endoscopic investigation is only advised in patients with pernicious anaemia. Our case did not have evidence of autoimmune or H. pylori infection but despite this she had CAG. We suggest considering gastroscopy for severe, unexplained vitamin B12 deficiency, particularly in this patient group.