Pathology of periportal fibrosis involution in human schistosomiasis

Abstract

Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections of periportal fibrosis caused by schistosomiasis mansoni in man. The material came from 14 wedge hepatic biopsies taken from patients with chronic advanced hepatosplenic disease and undergoing operations for the relief of portal hypertension. Besides the presence of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlarged portal spaces also showed hyperplasia of elastic tissue and disarray of smooth muscle fibers following destruction of portal vein branches. Eggs were scanty in the tissue sections, and matrix degradation probably represented involuting changes related to the progressive diminution of parasite-related aggression, which occurs spontaneously with age or after cure by chemotherapy. The changes indicative of matrix degradation now described are probably the basic morphological counterpart of periportal fibrosis involution currently being documented by ultrasonography in hepatosplenic patients submitted to curative chemotherapy.

Treatment by splenectomy of a portal vein aneurysm in hepatosplenic schistosomiasis

“…There were findings consistent with the diagnosis of hepatosplenic schistosomiasis, including the patient's origin from an endemic area, the ultrasonographic findings of intense wall thickening of the portal venous system up to the tertiary ramifications (the counterpart of Symmers' or pipestem fibrosis) and an increased left liver lobe contrasting to a reduced right lobe 9,12 . The definitive diagnosis was made by a liver biopsy, considering the typical findings of portal fibrous enlargement, preservation of the lobular architecture and angiomatoid formations; furthermore, the presence of isolated muscle cells or fibers caused by the destruction of portal vein branches is specific for hepatosplenic schistosomiasis 2,3,11 . The absence of egg granulomas does not exclude the diagnosis, given the low sensitivity of this microscopic finding.…”