Clinicopathological characteristics of gastric IgG4-related disease: Systematic scoping review

Background and Aim: Gastric IgG4-related disease (IgG4-RD) can mimic malignancy, submucosal tumors (SMT), and ulcers, leading to over-triage and unnecessary medical interventions such as gastrectomy. The variability in the clinicopathological presentation of IgG4-related disease is not yet well defined, posing a diagnostic challenge. Methods: Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including “gastritis,” “stomach,” “gastrointestinal stromal tumor,” and “IgG4-RD” from their inception to December 28, 2021. Results: Thirty-nine articles, including 2 observational studies and 42 cases, were included in the systematic review. While bottom-heavy lymphoplasmacytic mucosal infiltration is a characteristic finding of gastric IgG4-RD, it was only present in less than half of the patients in the observational studies. Patients with gastric IgG4-RD were more likely to be diagnosed with gastrointestinal stromal tumor (GIST), gastric cancer, or peptic ulcer disease and their clinical course involved resection (51.3%) or even gastrectomy. Diagnosis of gastric IgG4-RD was most frequently made by post-operative pathological analysis. Conclusion: This systematic review summarizes the current understanding of the characteristics of gastric IgG4-RD. Increased awareness of gastric IgG4-RD as a differential diagnosis of gastric SMT or ulcers among clinicians is crucial in order to reduce unnecessary high-risk, invasive interventions.