Chronic pulmonary emboli. Sparing of affected regions of lung from noncardiogenic pulmonary edema.

In chronic pulmonary emboli, lung perfusion may be maintained by either recanalization of occluded pulmonary artery segments or collateral bronchial circulation. We present a case of noncardiogenic pulmonary edema superimposed on chronic pulmonary emboli, in which the occluded segments of lung were spared from pulmonary edema, but not from neutrophil infiltration. This case demonstrates that chronic emboli may lead to roentgenographic sparing in noncardiogenic pulmonary edema, similar to that previously reported in acute pulmonary emboli superimposed on noncardiogenic edema.