Electron microscopy of superficial bladder tumours and urothelium after intravesical doxorubicin.

The effects of intravesical doxorubicin on cells in superficial transitional cell carcinomas and adjacent urothelium were studied by electron microscopy. Nucleolar segregation, vacuolation of the cytoplasms, mitochondrial abnormalities and the breakdown of secondary lysosomes leading to autolysis were the main patterns of damage. Cell loss was by desquamation from the surface and random cell death in the deeper cell layers of the tumour and urothelium.