Surface topography of the healthy and diseased transitional cell epithelium of the human urinary bladder

51 biopsies from healthy and diseased epithelium from human urinary bladders were examined by scanning electron microscopy. The luminal surface of the cover cells was marked by microvilli and microplicae. The replacement of the cover cells takes place by simple desquamination. This exposes cover cells having numerous microvilli, and these later develop characteristic microplicae. The ability to form cover cells is lost by the transitional epithelium following tumour formation. No tumour-specific surface morphology was observed.