Mismatch repair deficiency in multifocal gastric epithelial neoplasia and non-dysplastic glands: Harbinger of Lynch syndrome in an autoimmune gastritis patient

A 66-year-old woman, with a first-degree family history of gastric cancer (GC), a personal history of endometrial intraepithelial neoplasia, and a recent diagnosis of GC, associated with a previously undiagnosed autoimmune gastritis (AIG), was referred to our Clinic. AIG diagnosis was made according the internationally-recognised Sydney-Houston criteria (i.e., atrophy of the corpus/fundus mucosa which spares the antrum in the absence of active Helicobacter pylori infection). Parietal cell antibodies were positive.