Main » Infectious diseases » Snail-mediated Helminthiases » Schistosoma mansoni
Photo 1. Adult Schistosoma mansoni in portal tract. Male and female schistosomes lodge in copula in the portal tract, mesenteric or vesical plexuseSchistosoma The figure shows a cross- section of a male and female Schistosoma mansoni in a branch of the portal vein. (x40)
Photo 2. Granuloma replacing egg of Schistosoma mansjni in liver.
Eggs may lodge ectopically in any tissues, where they cause characteristic granulomaSchistosoma^It has been suggested that toxic substances associated with the ova trigger the fibrotic procesSchistosoma In histological sections the ova are seen in the portal and periportal regionSchistosoma All types of reaction may be present from acute eosinophilic cellular infiltration to the dense collagenous deposition which leads to periportal fibrosis, (x 40)
Photo 3. Periportal fibrosis of the liver. Periportal fibrosis ('pipestem fibrosis') is the classical pathological hepatic lesion. The white areas which may be round, oval, or stellate, are due to the terminal fibrotic reaction originally caused by the presence of the ova in and around the portal venous radicleSchistosoma
Photo 4. Egyptian splenomegaly. The combination of enlarged, irregularly fibrosed liver, and greatly enlarged spleen is commonly called 'Egyptian hepatospleno- megaly'.
Photo 5. Ascites secondary to chronic portal hypertension in a Brazilian. The classical clinical feature of chronic Schistosoma mansoni infection is portal hypertension. The opening up of a secondary, circulatory shunt leads to the development of varices in the oesophageal and gastric veins, ascites and gross splenomegaly.
Photo 6. Petechial haemorrhageSchistosoma In children portal venous obstruction secondary to schistosomiasis may present as telangiectasis-like spots, as in this Brazilian child.
Photo 7. X-ray of oesophageal variceSchistosoma Oesophageal varices like those shown on this X-ray can rupture, leading to a fatal haematemesiSchistosoma
Photo 8. X-ray of colonic polyposiSchistosoma In the early stages of Schistosoma mansoni infection diarrhoea is a common complaint. Extensive polyposis of the colon sometimes occurSchistosoma This lesion is reversible with antischistosomal drug therapy.
Photo 9. Sigmoidoscopic view of colonic polypSchistosoma Four views of polyps in the descending colon.
Photo 10. Sigmoidoscopic view of colonic polyps too.
Photo 11. Polyposis of colon at post mortem. Massive polyposis of the colon with fatal intestinal haemorrhage occurred in this Egyptian farmer.
Photo 12. Biopsy showing Schistosoma mansoni eggs in polyposis of colon. Diagnosis is usually confirmed by demonstrating eggs of Schistosoma mansoni in the stool. However intestinal biopsy through a proctoscope or sigmoidoscope is alsa an effective means of finding eggs and establishing a definitive diagnosis of Schistosoma mansoni infection. It may also be positive in patients with Schistosoma haematobium or Schistosoma japonicum. (x 60)
Photo 13. Ectopic infection — Schistosoma mansoni infection of lung.
When the lungs are affected typical eggs may appear in the sputum. Ectopic lesions in the spinal cord result in a transverse myelitis and paralysiSchistosoma The lesions usually contain large numbers of ova in necrotic material surrounded by eosinophils, and multi-nucleated giant cellSchistosoma The CSF shows an increase in protein and cells, especially eosinophils, (x 60)
Photo 14. Cor pulmonale. Eggs may reach the lungs and other ectopic sites by metastatic blood spread. An end result of the periarteritis caused by the presence of eggs in the lungs is fibrosis of the pulmonary arterioles with pulmonary hypertension. This results in enlargement of the right heart, ie cor pulmonale.
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» Schistosoma haematobium
» Schistosoma japonicum
» Schistosomes Found Uncommonly in Man
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