[Pathology of primary pulmonary hypertension]

Morphological investigation of 12 cases of primary pulmonary hypertension (PPH) (4 males and 8 females, from 20 to 48 years old, duration of the disease from 1 to 10 years) is performed. Heart weight increase (from 390 to 640 g) and thickening of the right ventricle wall were observed. 3 groups were distinguished on the basis of histology: 1) plexigenic pulmonary arteriopathy (PPA)-2 cases, 2) recurrent pulmonary thromboembolism (RPT)-5 cases, 3) vein-occlusive disease (VOD-5 cases. The third group was divided into two subgroups: vascular-occlusive disease (VOD) with thrombotic lesions of arteries and veins and vein-occlusive disease proper (VOD-p) with thrombosis of pulmonary veins only. Morphometrically, thickening of arterial intima and media was found in PPA and RPT and in some cases of VOD-p. The thickening of the above layers in veins found in some cases of PPA and RPT was obviously secondary and indicated the development of mixed pre- and postcapillary pulmonary hypertension.