Pulmonary changes in schistosomal cor pulmonale.

Necropsy was performed in 32 cases of schistosomal cor pulmonale, and the lungs were studied by means of conventional histologic techniques, by serial sectioning, and by the method of plastic vascular casting. Fibrin deposition and marked endothelial cell hyperplasia were the main early changes evoked by schistosome eggs within small arteries and arterioles. A complex fibrin thrombus organization and revascularization, followed by congestion and dilatation of focal blood vessels, resulted in plexiform lesions. Vascular casts showed them to be purely arterial, to have a glomeruloid appearance, and to originate laterally or terminally in small arteries.