Diffuse alveolar damage associated with pulmonary thromboembolism

In contrast to other internal organs, pulmonary arterial hypoperfusion does not always show ischemic changes in the lung parenchyma. Pulmonary thromboembolism (PTE)-related lung injury is extremely rare except in the case of pulmonary infarctions, in which PTE occasionally causes necrosis of the parenchyma. We describe the case of an 86-year-old woman who presented with respiratory failure and bilateral ground-glass opacity predominantly the upper lobes. Autopsy revealed a saddle-shaped old organized thrombi in the main pulmonary artery, relatively fresh thrombi in both pulmonary arteries, and localized diffuse alveolar damage (DAD) in the bilateral upper lung fields. The hypoperfused regions resulting from the thromboembolism anatomically coincided with the pulmonary lesion where DAD was identified. Although PTE is not regarded as a causal factor of DAD, it might induce DAD as a result of hypoperfusion in limited cases.