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

Abstract

Objective 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. Methods Based on the diagnostic criteria of TPS, 412 urine samples from 143 patients with histological follow‐up data were retrospectively analysed, and the diagnoses were compared with the original cytological diagnoses. Results In total, 110 patients were histologically diagnosed with high‐grade urothelial carcinoma (HGUC), and 33 patients were diagnosed with low‐grade urothelial neoplasia. 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, and 45 patients (31.5%) were diagnosed as positive. After reclassification using TPS, urine samples from 11 cases (7.7%) were categorised as unsatisfactory, 34 cases (23.8%) were negative, 21 cases (14.7%) were categorised as having atypical urothelial cells, 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 low‐grade urothelial neoplasia. 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. Conclusions The Paris System for Reporting Urinary Cytology greatly contributes to the standardisation of urine cytology reports and significantly improves the diagnostic sensitivity for HGUC.

Effect of the Paris system for reporting urinary cytology with histologic follow‐up

“…Based on above methods, it is not a surprise that different, even opposite results were obtained in different institutions. For example, the frequency of AUC category was reported to decrease significantly in some institution however unaffected in others as shown in Table 4 3,5,6,17‐20,27,28,30‐39 …”

“…For example, the frequency of AUC category was reported to decrease significantly in some institution however unaffected in others as shown in Table 4. 3,5,6,[17][18][19][20]27,28,[30][31][32][33][34][35][36][37][38][39] 5 | CONCLUSION TPS represents a significant improvement in classification of urinary specimens. By using TPS, we are able to provide a uniform classification system focused on the detection of HGUC.…”

The Diagnostic Dilemma of Urothelial Tissue Fragments in Urinary Tract Cytology Specimens

“…However, three other studies reported cases classified as LGUN based on TPS criteria that showed HGUC on follow-up histology. In Ma et al, 6/143 (4.2%) cases were classified as LGUN, and follow-up histology showed LGUN in 4 cases and HGUC in 2 cases, resulting in a sensitivity of 12% and a specificity of 98% [41]. Roy et al classified 13/97 (13%) cases as LGUN, and of those, 3 were HGUC on follow-up biopsy [42].…”

The inclusion of nuclear area improves the Paris system for reporting urinary cytology

“…The Paris System for Reporting Urinary Cytology (TPS) was issued in 2016 with the aim of properly diagnosing high‐grade urothelial carcinoma (HGUC) and reducing the use of equivocal terms, such as “atypical” and “suspicious.” 1 TPS has addressed the wide variability among observers and facilities, and improved the diagnostic accuracy over that of conventional urinary cytology 2,3 . However, false‐positives of reactive urothelial cells have been reported in studies using TPS 4 .…”