Urothelial dysplasia and carcinoma in situ of the bladder.

Urothelial cells were pepsin-extracted from paraffin-embedded specimens taken from human nontumorous bladder mucosa, dysplasia, and carcinoma in situ. After Feulgen staining for DNA, nuclei were measured with an integrating microdensitometer. The measurements show that normal urothelium consists mostly of diploid nuclei. Dysplasia means that there is a predominance of tetraploid DNA values, whereas carcinoma in situ is characterized by a high percentage of aneuploid cells. In both dysplasia and carcinoma in situ there is a considerable percentage of diploid nuclei. Thus, DNA cytophotometry can be used for standardization of preneoplastic and early stages of tumor development in bladder cancer.