Histopathology of pulmonary hypertensive diseases

The spectrum of histopathological lesions of pulmonary hypertensive vascular disease is extraordinarily varied. A number of distinct patterns can be recognized, and these correlate with aetiological factors and clinical data. Recent research has yielded important new insights on the pathogenesis of pulmonary hypertension at the molecular and cellular level, and various key mechanisms are emerging. These include induction and maintenance of vasoconstriction, endothelial activation and proliferation, and thrombosis. In the light of these developments, a re-evaluation of lesions at the histopathological level is receiving a new level of significance, as histological data complement those from research based on non-morphological techniques. We review the main histopathological features of hypertensive pulmonary vascular disease in this perspective.