Pathology of pulmonary hypertension.

The pathology of pulmonary hypertension includes numerous abnormalities of the intima, media, and adventitia of the pulmonary vascular tree. A recently completed systematic analysis revealed high variability of morphologic measurements within a given pulmonary arterial hypertension (PAH) lung and among all PAH lungs, as well as distinct pathologic subphenotypes, and included a subset of lungs lacking intimal and medial remodeling. There was correlation between perivascular inflammation, remodeling, and hemodynamics. This article summarizes the pathologic features of the normal and abnormal pulmonary circulation, and correlations with animal models.