[Comparison of perioperative methylene blue-stained and permanent Papanicolaou-stained urine cytology to detect patients with high-grade urothelial cancer or the urinary bladder. Part 1].

INTRODUCTION: The aim of the study was to investigate whether intraoperative methylene blue-stained and permanent Papanicolaou-stained urine cytologies show comparable accuracy in detection of high-grade urothelial carcinoma. PATIENTS AND METHODS: The study included 130 patients; 50 patients were without malignancy (25 follow-up, 25 with hematuria). In 80 patients transurethral resection due to urothelial carcinoma was performed. Per patient two cytology specimens were prepared: one immediate methylene blue-stained specimen, which was evaluated by the surgeon, and one Papanicolaou-stained permanent cytology slide, which was blinded and evaluated by one urologist.
RESULTS: Cytology results of all patients without malignancy were unsuspicious irrespective of the staining method. Of 80 patients with urothelial carcinoma, 50 showed a low-grade tumor. Sensitivity of tumor detection was 20 and 30% for methylene blue/Papanicolaou-stained slides, respectively. Among 30 patients with high-grade carcinoma, 10 were detected by methylene blue cytology and 30 by Papanicolaou-stained slides, corresponding to a sensitivity of 40 and 100%, respectively.
CONCLUSIONS: The results of standard Papanicolaou-stained urine cytology in the detection of clinically relevant high-grade urothelial carcinoma are excellent. The quality of cytological tumor detection by methylene blue-stained cytology made by different evaluators is insufficient in our opinion.