Effect of contrast media on urinary cytopathology specimens

Abstract

Introduction: Urological dogma dictates that washings collected from the urinary tract for cytological assessment must be performed without interference from contrast agents that may alter cellular integrity and diagnostic interpretation. In practice, the initial contrast used to outline the upper tracts is commonly discarded with subsequent saline washings sent for cytology. We hypothesize that contrast washings do not affect the morphology of urothelial carcinoma cells or the integrity of cytology interpretation. Methods: Samples obtained from (1) human bladder cell lines; (2) urine from a human xenograft bladder cancer model using UC-3 cells; and (3) patients with urothelial carcinoma were subjected to various experimental solutions (water, saline, urine, and dilutions of contrast media) for different exposure times. After exposure to various different solutions, samples underwent cytological analysis to assess morphologic and degenerative changes. Results: No cytological differences were seen when cells were exposed to ionic, hyperosmolar, or non-ionic low-osmolar contrast agents for any exposures up to five minutes. Cells exposed to mixtures of contrast agents and urine also demonstrated no evidence of degenerative change. Cells exposed to water for greater than one minute demonstrated significant hydropic degeneration impacting cytological interpretation. At 40 minutes or later, all reagents caused severe degeneration when evaluating urine samples from the mouse bladder cancer model and from patients undergoing urothelial carcinoma. Conclusions: Commonly used contrast agents have no effect on urinary cytology up to five minutes. Contrast washings of the urinary tract should not be discarded and can be sent for cytological diagnosis if fixed within this time period.

Implementation of The Paris System for Reporting Urine Cytology improves diagnostic accuracy of selective upper urinary tract cytology

“…In the current study, the diagnostic accuracy of selective UUT cytology for HGUC, characterized by sensitivity, specificity, NPV, and PPV, did not differ significantly between the subgroups of specimens obtained before and after the application of contrast reagents. The effects of contrast agents on urinary tract cytology have been investigated in previous studies 13,14,18–20 . Andriole et al 13 .…”

“…The effects of contrast agents on urinary tract cytology have been investigated in previous studies. 13,14,[18][19][20] Andriole et al 13 demonstrated that low-osmolarity, nonionic agents may affect cellular morphology to a lesser extent than conventional high-osmolarity, ionic agents. This was further supported by the findings of another study wherein exposure to ionic contrast agents reduced the viability and adherence of urothelial cells.…”

“…This was further supported by the findings of another study wherein exposure to ionic contrast agents reduced the viability and adherence of urothelial cells. 18 Frees et al 14 reported that no cytologic differences were seen when cells were exposed to ionic or nonionic contrast agents for up to 5 minutes, and all reagents caused cellular degeneration at 40 minutes or later. The influence of time until fixation on the quality of cytologic interpretation has been previously described.…”

“…11,12 Although the effects of contrast agents have also been investigated, these studies have yielded conflicting results. 13,14 The latest European Association of Urology guidelines state that urinary cytology of the renal cavities and ureteral lumina is preferable before the application of a contrast agent for retrograde ureteropyelography 6 ; however, there is little evidence to support this. To the best of our knowledge, no previous studies have clearly delineated the effect of such contrast agents on TPS-based cytologic diagnosis.…”

“…The accuracy of selective UUT cytology is affected by various factors, including instrumentation, collection methods, and background hematuria 11,12 . Although the effects of contrast agents have also been investigated, these studies have yielded conflicting results 13,14 . The latest European Association of Urology guidelines state that urinary cytology of the renal cavities and ureteral lumina is preferable before the application of a contrast agent for retrograde ureteropyelography 6 ; however, there is little evidence to support this.…”