[Obliterating changes of pulmonary veins as the cause of pulmonary hypertension]

The clinical course and the necropsy study in a 9,7 year old boy with primary vascular pulmonary hypertension showed that it was due to an intrapulmonary venoocclusive disease. The inter- and intralobular veins and the venoles revealed fibrous intimal thickening up to subtotal obstruction or total occlusion. The etiology remains unknown. There were no thrombi of veins or arteries within the lung. It is supposed the intimal proliferation due to an unknown etiologic agent is primary and thrombosis secondary.