A Patient with Dyspnea, Cough, and Fever

Figure 1. A, Grocott methenamine silver (GMS) stain showing Pneumocystis organisms within a granuloma. Inset, digitally magnified Pneumocystis organism showing characteristic paired “dark bodies” diagnostic of Pneumocystis species. B, Immunohistochemical stain using antibodies directed against Pneumocystis species with use of the treptavidin-biotin immunoperoxidase method. The discreet nature of the organisms is overshadowed by an abundance of fragmented and collapsed forms that are not well visualized on the GMS stain.