[Ultrastructural stereometry of highly differentiated transitional cell tumors of the bladder].

Cytomorphometric examination of the normal urothelium, 3 primary, 3 recurrent papillomas of the urinary bladder and 3 cancers of stage I indicated that average relative volumes of the nucleus and cytoplasm in their cells are nearly similar. Since these bolumes increase simultaneously in the tumors concerned, there is no change in the "nucleus-cytoplasm correlation" or "index" described above. Cytomorphometric indices of the nucleus and cytoplasma in papillomas are more close to those of high-differentiated cancer than of the normal urothelium. In histologically indistinguishable primary and recurrent transitional cell papillomas the indices would differ: in primary papillomas compared with the norma the amount of mitochondria is reliably increased statistically, but the volume of each of them is diminished, whereas in recurrent ones--vice versa.