Postmortem Findings

Postmortem histopathological evaluations of lung tissue from patients who died from SARS showed diffuse alveolar damage at various levels of progression and severity, consistent with the pathologic manifestations of acute respiratory distress syndrome (Ksiazek, Tsang, Poutanen).

The changes included hyaline membrane formation, interstitial mononuclear inflammatory infiltrates, and desquamation of pneumocytes in alveolar spaces (Ksiazek, Nicholls). There were also scattered foci of alveolar myxoid fibroblastic tissue, a finding consistent with the early organizational phase of progressive pneumonia. Interalveolar septa were mildly thickened, with a mild mononuclear infiltrate (Tsang). Bronchial epithelial denudation, loss of cilia, and squamous metaplasia were early features (Nicholls). The presence of hemophagocytosis