Flow cytometry in bladder cancer detection and evaluation using acridine orange metachromatic nucleic acid staining of irrigation cytology specimens.

A new technique for simultaneous multiparameter deoxyribonucleic acid, ribonucleic acid and nuclear size measurements by flow cytometry was applied to the examination of bladder irrigation cytology specimens from 107 urologic patients. The cell samples from patients with bladder carcinoma could be distinguished from normal by 2 features: 1) an increase in the proportion of bladder epithelial cells with more than diploid deoxyribonucleic acid and 2) aneuploid cell peaks. These criteria identified 12 of 13 cases of invasive carcinoma, 24 of 28 cases of carcinoma in situ and 11 of 13 cases of papillary carcinoma. An increased proportion of cells with more than diploid deoxyribonucleic acid or aneuploidy was found in 9 of 14 patients with papilloma and 6 of 19 patients with a history of bladder tumors but no evident disease at present--these were believed owing to increased epithelial proliferative rates or nuclear chromatin abnormalities not visible by light microscopy. None of the 20 patients who had never had bladder tumors was abnormal. While the results in this small clinical trial have been most encouraging an additional descriptor of nuclear chromatin structure is believed necessary to discriminate benign, reactive proliferative epithelium from neoplasm when the latter is near diploid or shedding few cells. Studies to develop such a parameter presently are under way.