The positive predictive value of suspicious for high-grade urothelial carcinoma in urinary tract cytology specimens: A single-institution study of 665 cases

BACKGROUNDThe Paris System proposes a 7-tier classification system for urine cytology. Establishing the risk of malignancy (ROM) associated with these diagnostic categories is essential to determine the appropriate management of patients. The objective of this study was to determine the ROM associated with the positive and suspicious categories. METHODSThe authors searched their electronic records for urine cytology specimens that had been diagnosed as positive or suspicious for high-grade urothelial carcinoma within an 11-year time frame. Then, the ROM was determined for these specimens within a 6-month follow-up interval. The cytologic diagnoses were correlated with surgical biopsy results, follow-up cytology results, and/or fluorescence in situ hybridization (FISH) results. RESULTSIn total, 662 specimens (487 positive and 175 suspicious), corresponding to 387 patients (295 men and 92 women), were included. The majority of specimens were collected by bladder washing (568 of 662 specimens; 85.4%) and for the indication of surveillance (601 of 662 specimens; 82%). On follow-up, bladder washing specimens were positive more often positive than voided urine specimens (466 of 570 [81.8%] vs 60 of 92 [65.2%]; P=.0005), and surveillance specimens were more often positive than specimens collected for other indications (82% vs 54.1%). The overall positive predictive value was higher for positive specimens than for suspicious specimens (365 of 461 [79.2%] vs 83 of 150 [55.3%]; P<.0001). CONCLUSIONSDiagnoses of suspicious for high-grade urothelial carcinoma, as used at the authors' institution, have an ROM that is high but is lower than that for the positive category. Therefore, the authors suggest keeping the 2 categories separate, although management should be aggressive in both groups. Cancer Cytopathol 2016;124:811-9. (c) 2016 American Cancer Society. Data are presented on the positive predictive value of urinary cytology when a diagnosis of suspicious for high-grade urothelial carcinoma and positive for high-grade urothelial carcinoma is rendered. The results of this 11-year experience with the diagnosis warrant its continued use in the Paris System.