Histologic manifestations of Blastomyces gilchristii infection in a 27-year-old woman, Ontario, Canada. A) Nonconsolidated lung. Thick hyaline membranes, characteristic of diffuse alveolar damage and acute respiratory distress syndrome, line the alveoli. Hematoxylin and eosin (H&E) stain, original magnification ×400. B) Consolidated lung. Alveoli are completely filled with B. gilchristii yeast cells and neutrophils. B. gilchristii cells are pale bluish-gray with a distinct cell border. H&E stain, original magnification ×100. C) Consolidated lung containing abundant B. gilchristii yeast cells with characteristic broad-based buds. Grocott methenamine silver stain, original magnification ×400.