Fig. 3: Histological and immunohistochemical features of IgG4-positive tissue specimens.
From: IgG4-positive plasma cells in nonspecific sialadenitis and sialolithiasis
a Strong lymphoplasmacytic infiltrates and dense strands of fibrosis visible in the tissue. Degeneration of the acini can also be observed. Hematoxylin and eosin (H&E), ×20, specimen A5. b Storiform fibrosis. Lymphocytes and plasma cells are seen interspersed in the fibrotic tissue. H&E, ×10, specimen B1. c Immunostaining for IgG4, with abundant IgG4-positive plasma cells. The IgG4 plasma cell count for this field is 90, corresponding to an IgG4/IgG ratio of 0.78 for this hotspot. ×40, specimen A1. d Obliterative phlebitis is sometimes absent in IgG4-related disease of the salivary gland. Immunostaining for CD31 shows lymphocytes and plasma cells visible in the lumens of venules (arrowheads). ×40, specimen A1.
