Primary pulmonary hypertension. Study of eight autopsy cases.

Eight autopsy cases of primary pulmonary hypertension were studied. All cases were diagnosed as primary plexogenic arteriopathy. Microscopical study of the lungs showed in every case hypertensive arterial changes of Grade II-VI after Health & Edwards' criteria. Truncal pulmonary artery of three cases revealed aneurysm or severe dilatation with thrombus, and dilation was also recorded in another three cases. Histology of gross pulmonary artery in several cases presented disruption and defect of elastic fiber and alcian-blue positive microcystic change in media, lymphoid cell infiltration in outer media and inner adventitia, adventitial thickening, and intimal fibrosis. The liver of 7 cases showed secondary congestive changes and in one case intrahepatic portal vasculitis.