Fig. 2
From: IgG4-related eosinophilic pleural effusion: a case report
Histopathologic examination of biopsy specimens from the right pleura. A: Hematoxylin–Eosin staining, 40×; B: Immunohistochemical staining for cluster of differentiation 138, 40×; C: Immunohistochemical staining for IgG4(40×) showing IgG4-positive plasma cells > 50/HPF; D: Immunohistochemical staining for IgG (40×) showing IgG4/IgG cell ratio > 40%