 The cysts resemble crushed ping-pong balls and are present in aggregates of two to eight (and not to be confused with "Histoplasma" or "Cryptococcus", which typically do not form aggregates of spores or cells).A lung biopsy would show thickened alveolar septa with fluffy eosinophilic exudate in the alveoli.Both the thickened septa and the fluffy exudate contribute to dysfunctional diffusion capacity that is characteristic of this pneumonia.