Feulgen-DNA-values in transitional cell carcinoma of the human urinary bladder.

Feulgen-stained imprint smears from 24 biopsy specimens from transitional cell carcinoma of the human urinary bladder were examined by means of scanning cytophotometry. One hundred randomly selected nuclei were measured from each biopsy specimen and the results compared with analogous measurements of nuclei from normal urinary transitional cell epithelium (13 cases in the control group). 97% of the nuclei in the control group were diploid. Well differentiated transitional cell carcinoma of the bladder mainly had a diploid DNA-stemline comprising 85% or more of the cells. One case of a well differentiated bladder cancer with a tetraploid DNA-stemline was found. The different cases of moderately differentiated bladder cancer showed diploid, triploid, tetraploid and hexaploid DNA-stemlines, while 4 out of 5 poorly differentiated tumours had a diploid DNA-stemline. The fifth extremely de-differentiated bladder carcinoma did not have any DNA-stemline at all. Together with these changes of the ploidy of the DNA-stemlines, increasing undifferentiation of the tumour tissue was combined with a reduced number of cells belonging to the tumour DNA-stemline, and increasingly scattered distribution of cells not contributing to the DNA-stemline. This indicates increased proliferative activity and/or chromosomal instability of the poorly differentiated cell population. Predominance of cells in the diploid, tetraploid and or octoploid intervals without marked frequency of DNA-values in the intermediary classes seemed to be a sign of clinical more "benign" bladder tumours, while a clinically more "malignant" tumour is characterized by increase of DNA-values in the triploid and hexaploid classes.