Proliferative pattern of urothelial bladder cancer and urothelial atypias.

For early diagnosis of urinary bladder tumors, autoradiographic, cytological, and impulse cytophotometric examinations were performed on fresh bladder tissue with carcinomas of different grades of malignancy and various depths of infiltration, and also on tissues with concomitant urothelial atypias. Cell kinetic examinations of urothelial atypias of mild, moderate, and severe grade revealed labeling indices comparable to those of urothelial carcinomas grade I, II, and III, respectively. The labeling indices of the carcinomas increased with both the grades of malignancy and the depth of invasion up to factor 5. Cytophotometrically mild atypias showed euploidy, while moderate to severe atypias revealed aneuploidy. By means of cytologic, cytophotometric, and cell kinetic analyses, two subgroups of G I urothelial carcinomas were distinguished. Subgroup I a corresponded to highly differentiated papillary urothelial carcinomas with low labeling indices, pap I-III differentiation, and euploidy. Subgroup I b, on the other hand, revealed pap differentiations of IV-V, aneuploidy, and higher labeling indices. This subgroup seems to be more prone to recurrences and apparently indicates higher grades of malignancy and depths of infiltration. The data presented provide evidence that a combination of these methods is helpful for early recognition of precursors of bladder cancer atypias as well as for exact evaluation of the biological potential of carcinomas.