Pathology of Pulmonary Vascular Disease with Radiologic Correlation.

Pulmonary hypertensive changes are commonly seen by the surgical pathologist, but the majority represents secondary changes due to some process extrinsic to the lung. Some primary, or idiopathic, vascular diseases result in unique pathologic changes including the plexiform lesion and venous hypertensive changes. Thromboembolic disease also shows unique pathologic features. Diffuse alveolar hemorrhage, vasculitis, and capillaritis often overlap, but may represent separate, distinct pathologic processes. Lastly, alveolar capillary dysplasia with misalignment of pulmonary veins, as well as chronic lung allograft vasculopathy, present as unique pathologies in the neonate and posttransplant recipient, respectively.