Fig. 5From: IgG4-related lung disease with recurrent pulmonary lesions during steroid therapy and difficulty in differentiating from malignancy: a case reportMicroscopic examination. a HE staining showing a dense inflammatory cell infiltrate consisting of plasma cells, lymphocytes, and neutrophils. b Immunohistochemical staining showing approximately 40 IgG4-positive cells per HPF, and an IgG4/IgG ratio of approximately 70%Back to article page