The histological diagnosis of IgG4‐related disease on small biopsies: challenges and pitfalls

Aims The pathological diagnosis of IgG4‐related disease (IgG4‐ RD ) relies on histology, IgG4‐positive cells, and an increased IgG4/IgG ratio. Small biopsies from patients with a presumptive diagnosis of IgG4‐ RD often fail to meet consensus histological criteria. The aims of this study were to evaluate consecutive small biopsies from patients with a presumptive diagnosis of IgG4‐ RD , and to assess the significance of the pathological findings....