BAL: Pneumocystis jirovecii - cysts (toluidin blue O staining )

France, CHU Dijon Parasitologie-Mycologie

With Toluidine blue only the cell wall of the cysts of Pneumocystis jirovecii gathered into clusters are well stained. The intracystic bodies are released through rupture of the mature cyst letting the empty thick-walled cysts collapse forming crescent-shaped bodies.