A case of pulmonary veno-occlusive disease in infancy.

A 1-year-old girl who had failure to thrive died suddenly of pulmonary veno-occlusive disease. In this case, the vascular disorder was due to nonthrombotic obstruction of only the postcapillary venules. This unusual pattern of involvement and the absence of thrombi, new or old, suggests that the pathogenesis of pulmonary veno-occlusive disease may involve mechanisms other than thrombosis.