(a)
(b)

Figure 2: Pathology of the parotid gland at the diagnosis of IgG4-RD. (a) IgG staining and (b) IgG4 staining. There are many plasma cells stained with IgG (a) and 90% of them were positive for IgG4 (b). IgG4-RD, IgG4-related disease; IgG, immunoglobulin G.