Figure 3.

Viral-associated pulmonary aspergillosis: impeded fungal growth pattern. (A and B) Images derived from a case of coronavirus disease (COVID-19)-associated pulmonary aspergillosis, showing acute inflammation of alveolar tissue visualized with hematoxylin and eosin staining (A) and Grocott-Gomori’s methenamine silver (Grocott) staining (B) at ×200 magnification. Dispersed presence of hyphal structures within pneumonia, only apparent upon Grocott stain, is indicated with black box (with magnification). (C and D) Patient with influenza-associated pulmonary aspergillosis, type impeded fungal growth. Grocott staining visualizes bronchopneumonia with fragmented hyphae (black circles/box for magnification), overall low fungal burden, and important neutrophilic infiltration, ×100 magnification.