Zbigniew Darzynkiewicz

Flow cytometry of low stage bladder tumors: Correlation with cytologic and cystoscopic diagnosis

Flow cytometry examinations (FCM) were carried out on 110 bladder irrigation specimens from 84 urologic outpatients who had had prior conservative treatment for low stage bladder tumors. The specimens were easily obtained, and adequately cellular in all cases. Of 60 examinations on patients with no cytoscopic abnormalities, FCM and conventional cytology were both negative in 30 and both positive in 12 instances; there were 18 with positive FCM and negative cytology. Of 15 instances with cystoscopically benign appearing papillary lesions, FCM and cytology were both negative in three and both positive in three cases; FCM was positive and cytology negative in nine. Of 35 instances with suspicious cystoscopic findings, FCM and cytology were both positive in 19 and both negative in four; FCM was positive and cytology negative in 12. There were no examples of positive conventional cytology and negative FCM. These findings indicate that, after conservative treatment of low stage tumors, FCM of bladder irrigation specimens may be a more sensitive measure of cytologic abnormalities than is conventional cytology. Specimen collection is feasible as part of the routine urologic examination in an outpatient clinic.

Flow Cytometry for Followup Examinations of Conservatively Treated Low Stage Bladder Tumors

A series of 26 conservatively treated patients with low stage bladder tumors was examined later by outpatient cystoscopy, conventional cytology and flow cytometry. Based on those findings the patients were separated into 5 groups. In the 4 patients in group 1 all findings persistently were negative. The 4 patients in group 2 had initially normal cystoscopy with progressively more abnormal flow cytometry and intermittently positive cytology; they subsequently suffered tumors. The 10 patients in group 3 had positive cystoscopy and flow cytometry, and intermittently positive cytology. The 6 patients in group 4 had negative cystoscopy with intermittently positive cytology and persistently positive flow cytometry. In all 6 cases flow cytometry was more sensitive than conventional cytology in detecting early and, sometimes, cystoscopically occult neoplasms. In the 2 patients in group 5 cystoscopically visible papillomas and low grade papillary carcinomas were found with negative flow cytometry and negative or suspicious cytology. The papillary tumors in these 2 patients were believed to be composed principally of benign or atypical epithelium, with too few malignant cells to be detected by present flow cytometry techniques. Our preliminary results suggest that flow cytometry may be a valuable tool for followup of patients who have had conservatively treated low stage bladder tumors and are at risk for development of carcinoma. In addition, the techniques may be used to monitor changes in the proportion of benign and malignant cells and, thus, can be of help in following the course of newly forming papillomas, papillary carcinomas or carcinoma in situ in papillomas or flat epithelium.