Prospective evaluation of urinary cytology in the VI-RADS 3 grey zone: association with muscle invasion in bladder tumors

Abstract VI-RADS 3 lesions represent a diagnostic grey zone for predicting muscle invasion in bladder cancer. We aimed to evaluate the association between preoperative urinary cytology and pathological muscle invasion and to assess its diagnostic performance in patients with VI-RADS 3 bladder tumors. In this prospective single-center cohort study, patients who underwent TURBT between September 2023 and September 2025 were evaluated. Among 241 consecutive patients, 57 with preoperative VI-RADS 3 lesions and available urinary cytology were included. The primary outcome was pathological muscle invasion (≥ T2). Given the few events, analyses were unadjusted: Fisher’s exact test, absolute difference in proportions, odds ratio (OR), and sensitivity, specificity, positive (PPV) and negative predictive values (NPV) with 95% confidence intervals (CIs). Muscle-invasive disease was detected in 5/57 patients (8.8%). Urinary cytology was positive in 12/57 (21.1%) and negative in 45/57 (78.9%). The rate of positive cytology was significantly higher in patients with muscle-invasive disease compared to non–muscle-invasive cases (80.0% vs. 15.4%, p = 0.006). Muscle invasion occurred in 4/12 (33.3%) patients with positive and 1/45 (2.2%) with negative cytology (absolute difference 31.1% points, 95% CI 9.5–58.8% points). Sensitivity was 80.0% (95% CI 28.4–99.5), specificity 84.6% (71.9–93.1), PPV 33.3% (9.9–65.1) and NPV 97.8% (88.2–99.9). In this cohort, positive urinary cytology was associated with muscle invasion in VI-RADS 3 tumors. Whether cytology adds diagnostic value beyond mpMRI or improves clinical decision-making requires validation in larger multicenter studies.