Urinary Cytologic Findings of Urothelial Lesions

Choi, Yoon Jung; Lee, Kwang Gil

Abstract

Urinary cytology is increasingly accepted as a diagnostic tool in the detection and follow-up of patients with bladder cancer. However, its value is reduced by several limitations, especially by the tack of cytologic criteria specifically reflecting the morphology of low-grade urothelial neoplasm. We reviewed histologically proven 50 cases of urine cytology with emphasis on cytologic findings of benign atypia and differential findings of urothelial neoplasm according to the grade. The diagnoses included 17 benign lesions (including 5 cases of urine calculi) and 33 malignant lesions(including 28 transitional cell carcinomas. 3 squamous cell carcinomas, 1 adenocarcinoma and 1 prostate adenocarcinoma). Diagnostic accuracy was 92%. Important cytodiagnostic criteria for benign atypia and low grade malignancy were cellularity, number of cell clusters, and morphology and arrangement of urothelial cells. The cytologic findings of urothelial neoplasms according to histologic grade were relatively well correlated with the histologic findings. However, the cytologic criteria were not sufficient to readily distinguish grade I from grade II. In view of this, we think that cytologic nomenclature "low-grade" and "high-grade" is a more reliable criterion. Recognition of subtle cellular morphologic features specific for urothelial lesions(including benign or malignancy) and proper fixation, processing and staining of specimen can expand the role of urinary cytology in detection and follow-up of patients.