*2.7.1.1 Histoplasmosis*

Histoplasmosis is caused by *H. capsulatum* (North America, river valleys) and *H. duboisii* (Africa), which are budding yeast cells with a diameter of 2–4 μm. Microorganisms are found in the cytoplasm of macrophages, histiocytes, and necrotic debris. Its capsule is stained with Giemsa or PAS reaction. Both organisms

**Figure 10.** *Necrotizing sarcoid granulomatosis: Granulomatous vasculitis. H&E.*

cause the formation of epithelioid cell granulomas; however, necrotizing granulomatosis is more often described in *H. capsulatum* infection [15].
