Outcome analysis and negative predictive value of the “unsatisfactory/nondiagnostic” category of The Paris System for Reporting Urinary Cytology

•In 2016, The Paris System (TPS) for Reporting Urinary Cytology (UCyto) was published and still there have not been any publications focusing on the outcome, risk of malignancy, or negative predictive value (NPV) of the unsatisfactory (UNSAT) category. We aimed to identtify the outcome and the NPV for UNSAT after the implementation of TPS at our institution.•The cases were deemed true negative (TN) if the 6 month follow up was negative. The urine specimen was considered "UNSAT" when it did not meet the adequacy criteria per TPS.•There were 230 (3.6%) UNSAT specimens from a total of 6348 UCyto specimens. Of these, 116 UCyto specimens from 106 patients, which had cytologic and/or surgical pathology follow-up within 6-months, were further studied. Only 50.7 % (106 of 209) of the patients had a follow-up.•An overall NPV of 84.4% was calculated for UNSAT UCyto. When this was compared with previous published worked for “negative” UCyto, it showed that the UNSAT UCyto according to TPS were lower for all indications and specimen types.•UNSAT UCyto is not equivalent to other UCyto categories and does not represent a “true negative” result. All other parameters, like history, clinical presentation, cystoscopy findings, and any prior UCyto or biopsy result, should be considered and patients managed accordingly.