RESUMEN
The results of a clinical, histopathological and biochemical study on twenty patients with schistosomal polyposis of the large bowel and ten patients with normal colon as a control are reported. The biopsy showed clearly the absence of any malignant or premalignant changes in all the twenty bilharzial patients. Results of the biochemical study showed that there is a statistically significant increase in beta-glucuronidase activity in schistosomal polypi compared to normal mucosa. This enzymatic activity is absent in schistosoma ova. The causes of the increase in the enzyme activity have been attributed to leucocytic infiltration present in schistosomal granulomata and possible to some degree of liver disfunction. The protein content of the excess mucus present in the colon could also activate the enzyme. Our results also show that the increased enzyme activity does not necessarily have carcinogenic properties. We did not come across a single case of malignancy even in a patient with very high level of enzyme activity (11615 units) or in those patients with a prolonged history of the disease.