Comparison of urine cytology diagnostic reports before and after the implementation of the Paris System classification system in China.

In 2013, The Paris System for Reporting Urinary Cytology (TPS) was developed as a uniform practical urine cytology system that could be applied worldwide. Here, we investigated the effectiveness of TPS diagnostic approach compared with that of the traditional urine cytological diagnosis method used in China.

Based on the diagnostic criteria of TPS, 412 urine samples from 143 patients with histological follow-up data were retrospectively analyzed, and the diagnoses were compared with the original cytological diagnoses.

In total, 110 patients were histologically diagnosed with high-grade urothelial carcinoma (HGUC), and 33 patients were diagnosed with low-grade urothelial neoplasia (LGUN). Based on the traditional urine cytological analysis method, 50 patients (34.9%) were diagnosed as negative, 48 patients (33.6%) were diagnosed as having atypical urothelial cells (AUC), and 45 patients (31.5%) were diagnosed as positive. After reclassification using TPS, urine samples from 11 cases (7.7%) were categorized as unsatisfactory, 34 cases (23.8%) were negative, 21 cases (14.7%) were categorized as having AUC, 12 cases (8.4%) were diagnosed as suspicious for HGUC, 59 cases (41.2%) were diagnosed with HGUC, and six cases (4.2%) were reclassified as having LGUN. Thus, after implementing TPS criteria, the sensitivity for positive malignancy diagnoses (HGUC alone) increased from 38.2% to 50.9%, while the specificity of the diagnosis was barely changed.

TPS greatly contributes to the standardization of urine cytology reports and significantly improves the diagnostic sensitivity for HGUC.

Cytopathology : official journal of the British Society for Clinical Cytology. 2020 Apr 04 [Epub ahead of print]

Cao Ma, Lihua Zhang

Department of Pathology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.