Hypertension and Vasculopathies

Pulmonary hypertension is defined as an increase in mean pulmonary arterial pressure of more than 25 mmHg at rest, assessed by right heart catheterization. It is a heterogeneous group of disorders that are classified based on differences in clinical, hemodynamic, and histopathologic features. The evolution in molecular medicine, medicinal diagnostics, and pharmacologic management has led to changes in its prognosis. Current classification of pulmonary hypertension, based on clinical presentation and hemodynamic features, includes five categories (Table 34.1). The role of biopsy in the diagnosis of pulmonary hypertension is limited to cases where the clinical and hemodynamic data are not diagnostic. In these cases, the final diagnosis has to be established by a multidisciplinary team led by the clinician. In this chapter, we will describe cases showing the common morphological patterns of pulmonary hypertension seen in histological specimen. These are most often seen in autopsy cases. There are plexogenic arteriopathy, veno-occlusive disease/capillary hemangiomatosis, congestive arteriopathy, hypoxic arteriopathy, and thrombotic arteriopathy.