The Pathology of the Arterial Pulmonary Vasculature in Manson's Schistosomiasis

¹ Department of Pathology, Paraiba University School of Medicine

Pulmonary vascular changes occurring in the course of pulmonary endarteritis of schistosomal nature were studied. The lesions were classified into three categories:

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(1) those caused by the impacted ova in the small pulmonary vessles and closely related to a reaction of hyperergic type, (2) lesions of diffuse arteritis and arteriolitis which together with hyaline thrombi constitute a manifestation of a hypersensitive phenomena, and (3) those associated with longstanding pulmonary hypertension, occurring in the media and intima of the pulmonary arteries and arterioles and characterizing the cardiopulmonary form of this parasitosis.

Portal hypertension seems to represent an important condition in the development of the cardiopulmonary schistosomiasis by establishing collaterals, short-circuiting the portal-systemic circulation, facilitating the passage of eggs, adult dead and live worms and schistosomules and their products from the liver into the lungs, giving rise to the characteristic obstructive syndrome of schistosomal pulmonary endarteritis.