Evaluation of human bladder tumors by ultrastructural morphometric techniques.

To estimate the malignancy of the human urinary bladder tumors, various cellular components of normal and neoplastic bladder epithelial cells were examined using morphometric techniques at the electron microscopic level. Nuclear to cytoplasmic ratios were found to be 1:5 in normal epithelial cells, 1:4 in superficial grade 1 (G1) tumor cells, 1:3 in superficial grade 2 (G2) tumor cells and 1:2 in invasive grade 3 (G3) tumor cells. Nuclear volumes were largest in G3 tumor cells, but no differences were seen in cell volumes between normal epithelial and tumor cells. The volumes and surface areas of the rough-surfaced endoplasmic reticulum (rER) and lysosomes per cell decreased progressively from G1 to G3 tumor cells. The volume density of tonofilaments was increased in G1, but decreased in G2 and G3 tumor cells. The cisternal thickness of the rER and Golgi complex was also increased in G1 tumor cells. From these results, it was concluded that morphometric analysis may be useful in evaluating the degree of differentiation and invasive potential of human bladder tumor cells in the low and intermediate risk groups.