Significance of atypical category in voided urine specimens prepared by liquid-based technology: Experience of a single institution

Introduction: The goal of this study was to evaluate the clinical significance of atypical cytology in voided urine samples. We also studied any differences in outcome that may exist between the patients being surveyed versus high risk for urothelial carcinoma (UC). Materials and methods: This was a retrospective study of all voided urine specimens with "atypical" cytology over a 10-year period. The patients were categorized into those with and without a prior diagnosis of UC as the "surveillance" and "de novo" (DG) groups. Follow-up was obtained. Clinical impact and outcomes of the 2 groups were compared. Results: In this study, 5.7% of voided urine specimens were atypical. Mean age of patients in years, male/female ratio, and time to diagnosis in days was 59 versus 71, 23:15 versus 22:1, and 95 versus 43 in the DG and surveillance group, respectively. Rate of progression to UC was similar in both groups. High-grade UC was significantly higher in the DG. Conclusions: Approximately 20% of patients in the DG were subsequently diagnosed with UC. The common causes for the atypical diagnosis that did not progress to UC were stones and benign prostatic hyperplasia. In the absence of an etiology for the atypia, further investigations are warranted.