Surface topography of the female bladder trigone.

Cystoscopic biopsy specimens of the bladder trigone of young women with recurrent urinary infections were examined by scanning electron microscopy. The superficial cells of the thickened squamous epithelium of the trigone have either a microridged, microvillous, or mixed pattern. In one case, bacteria were found adherent to all these types of surface. Some cells have a microvillous surface and a cobblestone pattern with long, clubbed microvilli and resemble the cells found in malignant and premalignant states.