Schistosomiasis and carcinoma of the bladder: a critical appraisal of causal relationship.

The pathology of 154 cases of carcinoma of the urinary bladder diagnosed in surgical specimens in Ibadan is reviewed. Schistosoma haematobium-infections are found in association with all varieties of urothelial carcinoma. The majority of tumours in this and previously reported series from bilharzial and nonbilharzial underdeveloped regions presented in advanced stages. It is suggested that the preponderance of squamous cell carcinoma in these regions is a reflection of late clinical presentation. The evidence so far presented to support a causal relationship between schistosomiasis and carcinoma of the bladder is reviewed. It is concluded that such relationship is probably not true.