*2.7.1.5 Pneumocystosis*

Most pathologists are familiar with the conventional picture of pneumonia caused by *Pneumocystis*, but 5–17% describe the formation of an ill-defined intraalveolar epithelioid or histiocytic granuloma around the eosinophilic exudate, sometimes without exudate; the formation of well-defined granulomas with central necrosis or without it is also possible [16, 17]. Sometimes the granulomatous reaction in pneumocystis pneumonia is a foreign-body granulomatosis (**Figure 13**).
