Stereological measurements of bladder tumour morphology

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.

Stereological estimates of nuclear volume correlated with histopathological grading and prognosis of bladder tumour

The aim of this retrospective study is to provide morphometric data which make grading of urinary bladder tumours objective and reproducible by stereological estimation of nuclear volume using the principle of estimating of the volume of particles of arbitrary shape. The study includes 92 specimens: 12 from normal bladder mucosa, and 80 from bladder tumours (15 grade I, 45 grade II, 19 grade III and one grade IV according to Bergkvist et al. 1965). After standard fixation, embedding, sectioning and hematoxylin-eosin staining, an unbiased estimate of the mean volume of nuclei sampled with a change proportional to the volume: (Formula: see text) was calculated. Here l0 is the length of the intercept through a test point hitting a nucleus measured in a random direction through the test point. The weighted means of nuclear volume in bladder tumours are spread over a wide range and show a strong correlation with the Bergkvist grade. Moreover, the relationship between the weighted mean volume of nuclei in bladder tumours and the prognosis is very good. Only one of 35 patients with a mean nuclear volume below 300 micron 3 died of bladder cancer whereas 18 of 19 patients with a mean nuclear volume above 500 micron 3 developed invasives tumours or died of their disease. This simple and fast estimate of nuclear volume seems to provide objective data of high prognostic value.

A morphometric study on the ultrastructure of well-differentiated tumours and inflammatory mucosa of the human urinary bladder

Transmission (TEM) and scanning electron microscopic (SEM) observations were performed on well-differentiated tumours and chronic cystitis in the human urinary bladder. SEM showed that the pleomorphic microvilli were present not only on the luminal surface of the tumour but also on the surface of inflammatory mucosa. The ultrastructure of six tumours and 5 cases of chronic cystitis was evaluated morphometrically. Bladder tumour and inflammatory mucosa were divided into several layers, namely outermost cells (S), subsurface cells just beneath these (S1), subsurface cells of 2 or 3 layers below (S23), intermediate cells of 2 or 3 layers above the basal cells (I23), intermediate cells just above the basal cells (I1) and basal cells (Ba). Areas of nucleus, cytoplasm and cytoplasmic organelles, numbers of nucleoli, nuclear bodies, mitochondria and lysosomes together with irregularity of the cell and nucleus were estimated according to the methods of Weibel. A multivariate analysis of variance on these variables showed that the above subdivision of layers was necessary for the comparison of tumour and inflammation. Discriminant analysis showed various differences between tumour and inflammatory mucosa. The results indicated that the Ba layer is the most effective site for differentiating the tumour from inflammation. Ba cells with large and irregular cytoplasm with an enlarged Golgi area, accompanied by many vacuolar structures, may be indicative of tumour rather than inflammation.

Cellular changes in rat urinary bladder carcinomas induced by FANFT: a quantitative electron microscopic analysis

Morphometric data of normal and neoplastic urinary bladder epithelia have been collected from the Fischer rat FANFT model. Sequential measurements of volumes, surface areas, and numerical densities of organelles, and where pertinent, cellular compartments have been made during FANFT carcinogenesis, utilizing standard point and intersection counting methods. The data show that neoplastic transformation of rat bladder epithelium, and progression of FANFT tumors are associated with increasing volume densities of cells, nuclei, microvilli, rough endoplasmic reticulum, and mitochondria, as well as with decreasing volume densities of the cytoplasmic matrix, fusiform vesicles, Golgi complex, and lysosomes. Surface densities of the plasma membrane (microvillar), nuclei, rough endoplasmic reticulum, as well as mitochondrial outer and inner membranes progressively increase while surface densities of non-microvillar plasma membrane, fusiform vesicles, and Golgi complex decrease with time. Smooth endoplasmic reticulum reaches its maximum volume and surface densities in tumors present 26 weeks after the initiation of FANFT feedings (26-F tumors). This may reflect the function of smooth endoplasmic reticulum as the site of detoxification of the carcinogen, noting that FANFT is metabolized by microsomal enzymes, and in this experiment is fed only for 26 weeks. The nuclear/cytoplasmic ratio is 1:4 in normal Fischer rat urothelium, 1:3 in 26-F and 43-F tumors, which are noninvasive, and 1:2 in 61-F, which are invasive tumors. The quantitative data correlate well with the changes in degree of differentiation of the tumors and with their biological behavior.