Bilharziasis of urinary bladder and ureter: comparative histopathologic study.

The relative incidence and intensity of oviposition in schistosomiasis in different layers of both the urinary bladder and the ureter are presented. Histopathological changes in both organs are elucidated. Oviposition was heaviest in the submucosa of the urinary bladder, while the muscle layer was affected in 15% of specimens. Oviposition was mainly periureteral and in outer muscle layer of the ureter, and was present in only 22% in the ureteral submucosa. Epithelial changes, namely, Brunn nests, cystitis glandularis, cystitis cystica, and squamous metaplasia, were more marked in the bladder specimens than in the ureteral specimens. Squamous cell papilloma and squamous metaplasia associated with acanthosis of the bladder specimens were identified. Results indicate unanimously that the heavy deposition of ova in the submucosa of the bladder leads through its mechanical and toxic irritation to marked epithelial and premalignant changes which pave the way for the disturbing frequency of carcinoma of the bladder in the bilharzial patients which is not the case in the ureter.