Figure 3B. Retrospectively analyzed immunoglobulin (Ig) G4 preparations in chronological order: Submandibular gland (left) with lymph nodes (right) 7 years before the diagnosis of IgG4-RD. (a) Low-power magnification (HE, ×10) of the submandibular gland (left side) and enlarged cervical lymph node (right side) with (b) increased number of lymphoid follicles (HE, ×100). At higher magnification (c), the germinal centers have a monotonous appearance with loss of proliferation areas (HE, ×200) and (d) increased numbers of plasma cells and eosinophilic granulocytes (HE, ×400). Immunohistochemistry shows significantly increased numbers of IgG4-positive plasma cells (e) relative to IgG-positive forms (f) (immunoperoxidase, ×200).