Fig. 3From: IgG4-related lung disease with recurrent pulmonary lesions during steroid therapy and difficulty in differentiating from malignancy: a case reportMicroscopic examination. a HE staining showed an inflammatory cell infiltrate consisting of plasma cells, lymphocytes, and neutrophils. b Storiform fibrosis was observed using the silver impregnation method. c Immunohistochemical staining showed that there were approximately 40 IgG4-positive cells per HPF, and the IgG4/IgG ratio was approximately 20%Back to article page