This is the typical appearance of Pneumocystis jiroveci cysts, with silver staining, with characteristic morphology: spherical or cup shaped cysts with a central thickening of its wall. Some of the cysts may have the appearance of smashed ping pong balls. The Papanicolaou or M-G-G stained material showed the typical alveolar casts, with a foamy appearance, highly suggestive of P. jiroveci pneumonia. The name of this fungus has been recently changed to Pneumocystis jiroveci, and the former name P. carinii is now used only for the organisms found in rats.