Utility of the Paris System in Reporting Urine Cytology

Impact of Implementing Paris System on Diagnostic Precision and Management of Urinary Bladder Neoplasms

The diagnosis of atypia has always been under question both by the pathologist and the clinician. It was one of the main aims of the Paris system (TPS) to reduce the number of cases under the AUC (Atypical urothelial cells) category. With the strict criteria laid down by the Paris system, the rate of diagnosis of this category has reduced markedly. This study was done to test the impact of implementing TPS categories and criteria in comparison to our previously used system. TPS is one of the important deciding factors for the management of the patient. The management of patients with AUC diagnosis often varies depending on the treating physician (urologist/nonurologist). For further categorization of the diagnosis of AUC, markers like p53 and Ki67 can be used. One hundred urinary cytology specimens received for the period of 6 months were included in the study. The presentation of the categorical variables was done in the form of numbers and percentages (%). Interrater kappa agreement was used to find out the strength of the agreement between the Paris system and the traditional system. Using histopathological diagnosis as the gold standard, sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic accuracy were calculated. Immunohistochemistry was performed on the cell block for Ki67 and p53, and their values were correlated with histopathological examination, using Spearman's rank correlation. The interrater kappa agreement analyzed between the traditional reporting system and the Paris system was 0.522. Around 32% (6/19) of cases that were reported as AUC by the traditional system were recategorized under negative for high-grade urothelial carcinoma (NHGUC) by the Paris system. Thus, obliviating the need for further management and decreasing the unnecessary cost of the health care system with a decrease in patient anxiety. Histopathology was available in 28 cases and diagnostic accuracy of urine cytology classified by TPS was 89.2% with a sensitivity of 94.4%, specificity of 80%, positive likelihood ratio of 89.4, and negative likelihood ratio of 88.6. The correlation coefficient of p53 with grading of carcinoma was found to be strong at 0.864. The correlation coefficient of Ki67 with grading of carcinoma was also as strong as 0.885. TPS along with immunohistochemistry improves the performance of urine cytology by reclassifying the AUC category into other groups and increases the sensitivity for detecting HGUC.

A comparison between conventional and the Paris systems of reporting urinary cytopathology with a literature update

INTRODUCTION

Owing to certain inherent limitations of earlier reporting systems, "The Paris System for Reporting Urinary Cytology (TPS)" was implemented in 2015 to standardize reporting urine cytology with more stringent cytomorphologic criteria. We share our post-TPS experience, comparing it with the conventional system (CS).

AIM

To assess and compare the cyto-histopathologic/cystoscopic agreement between the conventional and the Paris systems (CS and TPS) for reporting urine cytology.

MATERIALS AND METHODS

It is a cross-sectional study involving urine samples from 170 patients divided into two groups (CS and TPS). Of the 170 cases, 85 were reported according to the CS, and 85 were reported according to TPS with all the relevant clinical, radiologic, and cystoscopic findings. Using the kappa statistics, both groups were statistically analyzed for sensitivity, specificity, predictive values, and agreement.

RESULTS

The sensitivity and specificity for high-grade urothelial carcinoma (HGUC) as per TPS were 83.33% and 94.59%, respectively, while they were 73.47% and 80.56% for the conventional system. The agreement for HGUC with TPS was 87.06% with a kappa value of 0.7416, while it was 76.5% with a kappa value of 0.53 for the CS. Implementing the TPS minimized usage of the atypical urothelial cells (AUC) category, increasing the clarity in detecting HGUC.

CONCLUSION

TPS provides better agreement with histopathology than the CS for diagnosing HGUC, which is attributable to stringent TPS criteria that prompt cytopathologists to look more diligently for morphologic and numeric criteria.

International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer. Working Group 1: Comparison of Bladder Cancer Grading System Performance

Grade is a key prognostic factor in determining progression in nonmuscle invasive papillary urothelial carcinomas. The 2 most common grading methods in use worldwide are the World Health Organization (WHO) 2004 and 1973 schemes. The International Society of Urological Pathology (ISUP) organized the 2022 consensus conference in Basel, Switzerland on current issues in bladder cancer and tasked working group 1 to make recommendations for future iterations of bladder cancer grading. For this purpose, the ISUP developed in collaboration with the European Association of Urology a 10-question survey for their memberships to understand the current use of grading schemes by pathologists and urologists and to ascertain the areas of potential improvements. An additional survey was circulated to the ISUP membership for their opinion on interobserver variability in grading, reporting of urine cytology, and challenges encountered in grade assignment. Comprehensive literature reviews were performed on bladder cancer grading prognosis and interobserver variability along with The Paris System for urine cytology. There are notable differences in practice patterns between North American and European pathologists in terms of used grading scheme and diagnosis of papillary urothelial neoplasm of low malignant potential. Areas of common ground include difficulty in grade assignment, a desire to improve grading criteria, and a move towards subclassifying high-grade urothelial carcinomas. The surveys and in-person voting demonstrated a strong preference to refine current grading into a 3-tier scheme with the division of WHO 2004 high grade into clinically relevant categories. More variable opinions were voiced regarding the use of papillary urothelial carcinoma with low malignant potential.

Application of The Paris System in neobladder washing cytology: Comparison between the original diagnosis and correlation with histopathology

BACKGROUND

In urinary diversion after radical cystectomy, the incidence of recurrent urothelial carcinoma (UC) in upper urinary tract or urethra are reported in 2%-17% of the patients. Urine cytology plays a pivotal role in detecting the recurrence of UC. However, cytologic diagnosis in urinary diversion including neobladder is often challenging due to significant degenerative changes and necro-inflammatory background. Since the proposal of The Paris System (TPS) for reporting cytology, the utility of TPS in urinary diversion specimen has not been studied yet. The objective of this study is to evaluate the diagnostic usefulness of TPS compared with the original diagnosis and correlate with the matched histopathological results.

METHODS

Urinary diversion cytology specimens with concurrent or subsequent biopsy or resection at EUMC in recent 16 years (from January 2002 to December 2018) are retrospectively reviewed and reclassified according to TPS criteria. The TPS categories and the original diagnoses were compared and correlated with follow-up histology.

RESULTS

Concurrent or subsequent biopsy or resection within a 6-month period was available in 45 cases from 28 patients. When applying TPS, the rate of atypical and suspicious categories decreased by 13.4% and 11.1%. Using TPS increased the value of sensitivity, NPV, and accuracy to 93.75%, 93.75%, and 90.91%, respectively.

CONCLUSION

Application of TPS reduced the rate of indeterminate diagnoses and moreover, improved the sensitivity and accuracy of urinary diversion cytology. Therefore, we believe that diversion urine cytology diagnosis according to TPS is useful to screen patients for detection of recurrence in routine clinical practice.

Atypical urothelial cells classified according to the Paris System for Reporting Urinary Cytology: A 2-year experience with histological correlation from a Finnish tertiary care center-low rate and high risk of malignancy

BACKGROUND

The Paris System for Reporting Urinary Cytology (TPS) was issued to shift the focus of urine cytology to high-grade lesions to increase the diagnostic accuracy of urine cytology. The aim of this study was to evaluate the power of TPS in the atypical urothelial cells (AUC) category with histological correlation and follow-up.

METHODS

The data cohort consisted of 3741 voided urine samples collected during a 2-year period between January 2017 and December 2018. All samples were prospectively classified using TPS. This study focuses on the subset of 205 samples (5.5%) classified as AUC. All cytological and histological follow-up data were analyzed until 2019, and the time between each sampling was documented.

RESULTS

Of the 205 AUC cases, cytohistological correlation was possible in 97 (47.3%) cases. Of these, 36 (12.7%) were benign in histology, 27 (13.2%) were low-grade urothelial carcinomas, and 34 (16.6%) were high-grade urothelial carcinomas. Overall, the risk of malignancy was 29.8% for all cases in the AUC category, and 62.9% in the histologically confirmed cases. The risk of high-grade malignancy was 16.6% in all the AUC category samples and 35.1% in the histological follow-up group.

CONCLUSIONS

The performance of 5.5% AUC cases is considered good and within the limits proposed by TPS. TPS is widely accepted by cytotechnologists, cytopathologists, and clinicians; it improves communication and patient management.

Cyto-histo correlation and false-negative urine: Before and after the Paris system for reporting urinary cytology

BACKGROUND

The impact of implementing the Paris system (TPS) on the rate of discrepant cases in the negative for high-grade urothelial carcinoma (NHGUC) category that had a subsequent diagnosis of high-grade urothelial carcinoma (HGUC) on histology is not well studied.

METHODS

We adopted TPS in May 2019. We searched discrepant cases with negative urine cytology 2017-2019 in our cyto-histo correlation database. The urine cytology and follow-up biopsy/resection were reviewed by a cytopathologist who also did Genitourinary (GU) Pathology subspecialty sign-out. Voided urine and instrumented urine were included in this study.

RESULTS

There were total of 70 discrepant cases with negative cytology interpretation but HGUC on the subsequent biopsy or resected specimen. Following the TPS criteria, the rate of discrepant negative cytology cases increased from 6 cases between January 2017 and May 2019 to 64 cases after May 2019 when we adopted TPS. There were 2 discrepant negative cases in 2017, 3 cases in 2018, and 65 cases in 2019. Out of 65 cases in 2019, 64 cases were identified after May 2019. Additional 55 urine cytology slides were reviewed according to the TPS criteria, of which, the diagnoses remained unchanged in 45 (82%) cases and 10 (19%) cases were reassigned to either atypical or suspicious categories. The discrepancy was noted more on the instrumented urine and the upper tract urine. However, the false-negative rate rose faster in voided urine and lower tract urine. The risk of HGUC with the category of NHGUC was 0.03% in 2017, 0.05% in 2018, and 1.06% in 2019 at our institution. The increase in false-negative rate could not be attributed to a single cytopathologist.

CONCLUSION

After adopting TPS for reporting urine cytology, there was an increase in HGUC from negative urine cytology which was subsequently confirmed on histology as cases of HGUC. The quality control of negative urines could be important monitoring the process when implementing TPS.

Xpert Bladder Cancer Monitor May Avoid Cystoscopies in Patients Under "Active Surveillance" for Recurrent Bladder Cancer (BIAS Project): Longitudinal Cohort Study

Objectives

To test the hypothesis that patients under active surveillance (AS) for Non-muscle Invasive Bladder Cancer (NMIBC) who were negative on longitudinal re-testing by the Xpert^® Bladder Cancer Monitor (Xpert BC Monitor) assay may avoid unnecessary cystoscopies and urine cytology (UC).

Subjects/Patients (or Materials) and Methods

This is a prospective cohort study of patients enrolled in the AS protocol for recurrent NMIBC (Bladder Cancer Italian Active Surveillance, BIAS project), whose urine samples were analyzed by Xpert BC Monitor upon entry in the study (T0). Patients who had a negative Xpert test and did not fail AS, underwent additional Xpert tests after 4 (T1), 8 (T2), and 12 (T3) months. The clinical utility of Xpert was assessed by determining the number of cystoscopies and UC that could be avoided within 1 year.

Results

Overall, 139 patients were tested with Xpert at T0. Median follow-up was 23 (IQR 17–27) months. Sixty-eight (48.9%) patients failed AS, 65 (46.7%) are currently on AS, and 6 (4.3%) were lost at follow-up. At T0 57 (41.0%) patients had a negative test and 36 (63.2%) are still in AS. In patients with 2 consecutives negative Xpert tests, we could have avoided 73.9% of unnecessary cystoscopies, missing 26.4% failure, up to avoid all cystoscopies with 4 negative tests missing only 12% of failure. All the patients with negative Xpert had negative UC. Failure-free-survival at median follow-up (23 month) stratified for having 0, 1, or ≥2 negative tests was 67.0, 55.1. and 84.1, respectively.

Conclusion

Our findings suggest that Xpert BC Monitor assay, when it is longitudinally repeated, could significantly reduce the number of unnecessary cystoscopies and UC during their follow-up.

Digital image analysis of high-grade urothelial carcinoma in urine cytology confirms chromasia heterogeneity and reveals a subset with hypochromatic nuclei and another with extremely dark or "India ink" nuclei

BACKGROUND

The Paris System for Reporting Urinary Cytology (TPS) uses hyperchromasia as major diagnostic criterion for high-grade urothelial carcinoma (HGUC). The purpose of the study was to evaluate cases that were diagnosed as HGUC by TPS and determine whether there are different chromatin distribution patterns (ie, subsets).

METHODS

Digital image annotations were performed on microscopic images of HGUC urine specimens with surgical biopsy/resection follow-up. Median gray values were generated for each cell. Neutrophils (polymorphonuclear leukocyte [PMN]) were also enumerated in each case to serve as an internal control. A HGUC/PMN ratio was generated for each case, and the cases were distributed.

RESULTS

Sixty-nine HGUC cases yielded 2660 cells, including 2078 HGUC (30.1 cells/case) and 582 PMNs (8.4 cells/case). The average median gray value of an HGUC was 50.6 and of a PMN was 36.8 (P < .0001). Eight of 69 cases (11.6%) contained nuclei that, on average, were darker than or as dark as a PMN (extremely dark, ie, "India ink"). Fifty-one of 69 cases (74.0%) contained nuclei that, on average, were slightly brighter than a PMN (hyperchromatic). Ten of 69 cases (14.5%) contained nuclei that, on average, were much brighter than a PMN (hypochromatic). Within a single case, all cases showed heterogeneity with the hypochromatic cases showing the most dramatic effect.

CONCLUSIONS

Digital image analysis reveals that there are large variations in chromasia between cases including a subset of cases with hypochromasia and another with extremely dark or "India ink" nuclei. There was much heterogeneity of chromasia seen within a single sample.

The Paris System for Reporting Urinary Cytology: A Meta-Analysis

The Paris System (TPS) for Reporting Urinary Cytology is a standardized, evidence-based reporting system, comprising seven diagnostic categories: nondiagnostic, negative for high-grade urothelial carcinoma (NHGUC), atypical urothelial cells (AUC), suspicious for high-grade urothelial carcinoma (SHGUC), HGUC, low-grade urothelial neoplasm (LGUN), and other malignancies. This study aimed to calculate the pooled risk of high-grade malignancy (ROHM) of each category and demonstrate the diagnostic accuracy of urine cytology reported with TPS. Four databases (PubMed, Embase, Scopus, Web of Science) were searched. Specific inclusion and exclusion criteria were applied, while data were extracted and analyzed both qualitatively and quantitatively. The pooled ROHM was 17.70% for the nondiagnostic category (95% CI, 0.0650; 0.3997), 13.04% for the NHGUC (95% CI, 0.0932; 0.1796), 38.65% for the AUC (95% CI, 0.3042; 0.4759), 12.45% for the LGUN (95% CI, 0.0431; 0.3101), 76.89 for the SHGUC (95% CI, 0.7063; 0.8216), and 91.79% for the HGUC and other malignancies (95% CI, 0.8722; 0.9482). A summary ROC curve was created and the Area Under the Curve (AUC) was 0.849, while the pooled sensitivity was 0.669 (95% CI, 0.589; 0.741) and false-positive rate was 0.101 (95% CI, 0.063; 0.158). In addition, the pooled DOR of the included studies was 21.258 (95% CI, 14.336; 31.522). TPS assigns each sample into a diagnostic category linked with a specific ROHM, guiding clinical management.

Analytical and post analytical phase of an ISO 15189:2012 Certified cytopathology laboratory-a five year institutional experience

Objective:

Analytical and post analytical phase are integral part of total quality management system and include steps from submission of slides till reports are dispatched. The present study was conducted to analyze the analytical and post analytical phase of the ISO15189:2012 certified cytopathology laboratory. It was also intended to study the various errors which were encountered and steps taken to reduce these discrepancies.

Methods:

The study included all documents of quality program from 1 November 2014 till 31 Oct 2019 in medical institute situated in north Himalayan region of India. All the data was recorded and analyzed for analytical and post analytical phase.

Results:

The number of samples received in cytopathology lab was 21,566 with total quality errors of 5.19%. Out of these pre-analytical errors were 55%, analytical 10.5% and post analytical errors constituted 34.4%. The maximum errors detected were due to typographical errors followed by delayed turnaround time. Cyto-histopathological discordance was 10.5% in non-gynecological cases and 2.2% in gynecological cases.

Conclusion:

Analytical and post analytical phase analysis is essential to minimize the errors and improve the quality of cytopathology lab. Cyto-histopathological correlation is valuable for continuous data tracking in the cytopathology with analytical errors analysis. Maintenance of external, internal quality program, turnaround time with documentation, continuous training and communication with clinician is fundamental for quality improvement in any cytopathology lab. Acknowledgement of nonconformance with root cause analysis and sincere efforts to minimize them is the basic key for successful quality management.

Urine cytology findings in patients with biopsy-confirmed urothelial carcinoma in situ with plasmacytoid features

BACKGROUND

Urine cytology is an important screening tool in the diagnosis of high-grade urothelial carcinoma. Diagnosis in urine samples follows criteria outlined by The Paris System for Reporting Urinary Cytology (TPS). However, cytologic characteristics of the recently described urothelial carcinoma in situ with plasmacytoid features (P-CIS) have not been described, and it is unknown whether they conform to TPS criteria for high-grade urothelial carcinoma. This study was aimed at better characterizing possibly unique cytologic features of P-CIS.

METHODS

The authors collected urine cytology specimens from patients with subsequent bladder biopsy-proven P-CIS. Specimens were re-reviewed according to the TPS criteria. The proposed cytologic features of P-CIS (eccentric, enlarged, and hyperchromatic nuclei) were evaluated; this included the reproducibility of 3 cytopathologists for the proposed cytologic features.

RESULTS

Seventy-four urine specimens from 18 patients with P-CIS-diagnosed bladder biopsies were identified. The TPS diagnoses of the 74 urine cytology specimens were as follows: negative for high-grade urothelial carcinoma (n = 26), atypical urothelial cells (n = 26), suspicious for high-grade urothelial carcinoma (n = 12), and high-grade urothelial carcinoma (n = 10). Only 7 urine specimens met the proposed cytologic criteria for P-CIS, and they had TPS diagnoses of negative for high-grade urothelial carcinoma (n = 1), atypical urothelial cells (n = 3), and high-grade urothelial carcinoma (n = 3). The κ interobserver agreement ranged from poor to fair.

CONCLUSION

The features of P-CIS on urine cytology are subtle and infrequently reproducible and often do not meet the TPS criteria for diagnosis as high-grade urothelial carcinoma. In specimens that do not meet TPS criteria for high-grade urothelial carcinoma, P-CIS cytology in isolation would be best classified as atypical urothelial cells.

High-grade urothelial carcinoma with hypochromatic chromatin in urine cytology

INTRODUCTION

Some high-grade urothelial carcinomas (UCs) in urine cytology have hypochromatic chromatin, but the incidence and criteria for diagnosis are not well described.

MATERIALS AND METHODS

Urine cytology cases with biopsy follow up were reviewed.

RESULTS

Cytospin preparations from 331 cases with biopsy follow up (230 benign/low-grade UC, 101 malignant) were reviewed. There were no false-positive cases. Cases with malignant cells with hypochromatic chromatin were identified in a total of 17 cases (16.8% of all malignancies). These comprised 2 carcinoma in situ, 11 high-grade papillary UC, 3 invasive UC, and 1 adenocarcinoma. Sixteen of 93 high-grade UCs (17.2%) had cells with hypochromatic chromatin. These cells were the only type of malignant cell in 4 of 101 cases (4.0%). All cases had cells with high nuclear-to-cytoplasmic ratios and markedly indented and irregular nuclear membranes that could be identified on both cytology and subsequent histology.

CONCLUSIONS

Malignant urothelial cells in urine cytology with hypochromatic chromatin can be present in 17% of cases and can be diagnosed as "positive for malignancy" based on their high nuclear-to-cytoplasmic ratio, and markedly indented and irregular nuclear membranes.

Experience on the use of The Paris System for Reporting Urinary Cytopathology: review of the published literature

INTRODUCTION

The Paris System for Reporting Urinary Cytology (TPS) was first published in 2016 with clear objectives to standardize cytologic diagnostic criteria and provide uniform reporting, in order to improve patient stratification and associated clinical management. The aim of this paper is to evaluate the performance of TPS and review the literature published since TPS was introduced.

MATERIALS AND METHODS

Original articles focusing on the utilization and performance of TPS in urinary cytology specimens were identified using PubMed for publications from January 2016 to July 2020, using the keywords "Paris System", "urine cytology", and "urinary cytology".

RESULTS

Twenty-three relevant articles in the literature regarding the use of TPS were included in the review from a total of 30,802 urine cytology specimens, of which 21,485 (69.8%) had available diagnoses. Distribution of cases among categories ranged from 50.5% to 95.3% for negative for high-grade urothelial carcinoma (NHGUC), 1.2% to 23% for atypical urothelial cells (AUC), 0.2% to 6.6% for suspicious for high-grade urothelial carcinomas (SHGUC), and 2.2% to 14.1% for high-grade urothelial carcinomas (HGUC). The calculated risk of high-grade malignancy (ROHM) ranged from 8.7% to 36.8% for NHGUC, 12.3% to 60.9%% for AUC, 33.3% to 100% for SHGUC, and 58.8% to 100% for HGUC. Mean ROHM weighted by sample size was calculated at 15.7% (±7.8%), 38.5% (±14.3%), 76.2% (±17.2%), and 88.8% (±12.7%) for NHGUC, AUC, SHGUC, and HGUC, respectively. Reported sensitivity of TPS ranged from 40% to 84.7%, specificity from 73% to 100%, PPV from 62.3% to 100%, and NPV from 46% to 90%.

CONCLUSIONS

The application of TPS in the selected series has improved the screening and surveillance potential of urine cytology, while reducing high rates of indeterminate diagnoses, improving sensitivity and providing proper risk stratification for patients.

Should "suspicious for high-grade urothelial carcinoma" and "positive for high-grade urothelial carcinoma" remain separate categories?

BACKGROUND

The Paris System (TPS) for Reporting Urinary Cytology aims to standardize urine cytology reporting. Per TPS, the diagnosis of "suspicious for high-grade urothelial carcinoma (SHGUC)" is applied in cases that have few urothelial cells with severe atypia but are quantitatively insufficient for a diagnosis of "high-grade urothelial carcinoma (HGUC)." In our study, we compared the diagnostic accuracy and risk of malignancy (ROM) of these 2 categories to assess whether they could be combined in clinical practice to perhaps improve overall interobserver variability.

METHODS

All urine specimens with a diagnosis of either SHGUC or HGUC from January 2016 to July 2019 were retrieved from the pathology database of 2 large academic institutions. Only cases with follow-up biopsies within 6 months were included.

RESULTS

One hundred eighty-nine cases met the study criteria. Of these, 122 had a cytologic diagnosis of SHGUC, and 67 had a diagnosis of HGUC. Ninety-five (78%) cases from the SHGUC group and 64 (96%) cases from the HGUC group had biopsy-proven HGUC. The majority of cases with discordance had a history of treatment with either intravesical bacillus Calmette-Guérin or mitomycin. The difference in the rate of biopsy-proven HGUC between the SHGUC category and the HGUC category (95/122 vs 64/67, respectively) was statistically significant (P < .001).

CONCLUSIONS

The difference in ROM between SHGUC and HGUC was statistically significant in our study cohort. Intravesical chemotherapy was frequently observed in negative biopsy cases in both groups. Our preliminary findings suggest that the 2 TPS categories should remain separate.

The Paris System for Reporting Urinary Cytology reduces atypia rates and does not alter the negative predictive value of urine cytology

INTRODUCTION

The Paris System for Reporting Urinary Cytology (TPS) was developed for standardization purposes and it placed an emphasis on screening for high-grade urothelial carcinoma (HGUC). Since then, it has shown to reduce atypia rates and better correlate with surgical specimens. The aim of this study was to calculate the negative predictive value (NPV) of urinary cytology for detecting HGUC using TPS and compare these data to our recently published pre-TPS cohort. As a screening test, it is imperative that TPS has a high NPV.

MATERIAL AND METHODS

A search of our institution's pathology database for the term "negative for HGUC" from January 1, 2016, to December 31, 2017, was conducted. A true negative was defined as a patient with at least 1 subsequent negative urine cytology/surgical biopsy specimen or the patient being clinically negative for 6 months. NPV rates were calculated based on the data obtained.

RESULTS

The cohort consisted of 2960 urine cytology specimens from 1894 patients. A total of 99 false negatives were identified, generating a NPV of 96.7% (2861/2960). This NPV is identical to our previously published pre-TPS cohort (years 2012-2013; NPV: 96.7%). The clinical indication most effected NPV, with a history of urothelial carcinoma with a NPV of 93.9% followed by hematuria at 98.9%. The atypia rate in years 2012-2013 was 8.2% and in 2016-2017 it was 5.7% (P < 0.001).

CONCLUSIONS

We demonstrate that TPS did not alter the NPV for detecting HGUC compared to our pre-TPS cohort. We believe that TPS is an effective reporting system for screening HGUC in urinary cytology.

The Paris system of Reporting Urinary Cytology: Strengths and opportunities

The Paris system for reporting urinary cytopathology (TPS) was created to address inherent weaknesses inherent in the practice of urinary cytopathology. While urothelial cytology has always performed well at finding high grade, genetically unstable urothelial carcinoma, it performs poorly when it comes to detecting low-grade urothelial neoplasia. TPS intends to improve the utility of urothelial cytology by focusing on what is important, high-grade urothelial carcinoma. This article is a snapshot of the current state of TPS as it heads into its second edition. Successes are described and further developments are considered.

High-grade urothelial carcinoma in urine cytology: different spaces - different faces, highlighting morphologic variance

INTRODUCTION

The Paris System for Reporting Urinary Cytology (TPS) was first published in 2016 to standardize reporting and placed a specific emphasis on high-grade urothelial carcinoma (HGUC). The urinary tract is anatomically divided into the upper tract (UT) and the lower tract (LT). A major morphologic criterion in TPS for HGUC defines the nuclear-to-cytoplasmic (N/C) ratio as ≥ 0.7. In this study, we evaluated N/C ratios of HGUC arising from UT and LT urine specimens, to ascertain differences due to location.

MATERIALS AND METHODS

Digital annotations of whole slide scanned images were performed and enumerated.

RESULTS

The cohort consisted of 59 ThinPrep specimens from 52 patients. The majority of the tumors were located in LT (39 of 59, 66.1%). A total of 590 cells were analyzed (10 cells per case). In UT, the average N/C was 0.58 and LT the average was 0.54 (P < 0.001). The average nuclear area for UT was 126.3 and for LT was 158.2 μm² (P = 0.01). The average cytoplasmic area for UT was 219.1 μm² and for LT was 296.2 μm² (P < 0.001). The average cellular circumference for UT was 59.4 μm and for LT was 66.1 μm (P < 0.001).

CONCLUSIONS

We found that UT HGUCs have higher N/C ratios, smaller cell circumference, smaller nuclei, and less cytoplasm compared with LT. When UT was divided into renal pelvis and ureter, no statistical difference was identified.

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

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.

Reclassification of urinary cytology regarding The Paris System for Reporting Urinary Cytology with cytohistological correlation demonstrates high sensitivity for high-grade urothelial carcinoma

BACKGROUND

Recently, The Paris System for Reporting Urinary Cytology (TPS) has led to major changes in the approach to evaluate urine cytology and pattern of reporting. The aim of this study was to reclassify urine cytology reports with TPS in order to determine the frequency of abnormal results compared with the previous system; also, we performed cytohistological correlation in abnormal cytological results.

METHODS

In this study, the voided urine specimens from the patients referred to Shiraz University of Medical Sciences affiliated laboratories were retrieved and analyzed using the laboratory's electronic records system; slides prepared from the samples were reviewed by single cytopathologist blindly according to the proposed criteria of TPS.

RESULTS

Totally, 1842 urine cytology slides from 828 patients were blindly evaluated by TPS criteria and compared with routine urine cytology classification. Then, available cytohistological correlation was done on 99 abnormal urine cytological results from 58 patients. Among the 26 cytology slides with atypical urothelial cell (AUC) in the previous classification, eight (30.70%) slides were downgraded to negative results, and four (15.30%) were upgraded to higher groups. Therefore, through the reclassification of the slides with TPS, 46% of the AUC changed to other groups. Diagnostic accuracy of the TPS classified urine cytology was 78%, including 87.88% sensitivity, 27.27% specificity, 64.44% positive predictive value, and 60% negative predictive value.

CONCLUSION

The findings of the present study confirmed the importance and utility of TPS regarding the reclassification of AUC to other groups and its high sensitivity for detecting high-grade urothelial carcinoma (HGUC).

Diagnostic Agreement for High-Grade Urothelial Cell Carcinoma in Atypical Urine Cytology: A Nationwide Survey Reveals a Tendency for Overestimation in Specimens with an N/C Ratio Approaching 0.5

In the Paris System (TPS), standardized cytomorphological criteria and diagnostic categories were proposed for reporting urine cytology. To evaluate the diagnostic agreement and interobserver concordance for assessing TPS criteria, the Taiwan Society of Clinical Cytology organized an online survey with 10 atypical urine cytology cases. A total of 137 participants completed the survey. The mean agreement of diagnosis was 51.2%, ranging from 34.3% to 83.2% for each case. For 60% (6/10) of cases, the agreement was <50%. The interobserver concordance of diagnosis and cytological criteria assessment showed poor agreement. The nuclear-to-cytoplasmic (N/C) ratio had the highest kappa value of 0.386, indicating a significantly higher interobserver concordance and reproducibility than the other three TPS criteria. The correct rate of assessing the N/C ratio increased as the N/C ratio increased (correlation coefficient: 0.891, p < 0.01). Three cases with an N/C ratio near 0.5 were overestimated. Poor interobserver concordance of diagnosis and TPS criteria was revealed. Compared with other cytological features, the N/C ratio assessment was quantitative and more reproducible, but a tendency to overestimate cells was noted when the N/C ratio was approximately 0.5. Continuing education programs should emphasize the accurate assessment of N/C ratio to improve the application of TPS.

Impact of the Paris system for reporting urine cytopathology on predictive values of the equivocal diagnostic categories and interobserver agreement

Background:

The Paris System (TPS) acknowledges the need for more standardized terminology for reporting urine cytopathology results and minimizing the use of equivocal terms. We apply TPS diagnostic terminologies to assess interobserver agreement, compare TPS with the traditional method (TM) of reporting urine cytopathology, and evaluate the rate and positive predictive value (PPV) of each TPS diagnostic category. A survey is conducted at the end of the study.

Materials and Methods:

One hundred urine samples were reviewed independently by six cytopathologists. The diagnosis was rendered according to TPS categories: negative for high-grade urothelial carcinoma (NHGUC), atypical urothelial cells (AUC), low-grade urothelial neoplasm (LGUN), suspicious for high-grade urothelial carcinoma (SHGUC), and high-grade urothelial carcinoma (HGUC). The agreement was assessed using kappa. Disagreements were classified as high and low impacts. Statistical analysis was performed.

Results:

Perfect consensus agreement was 31%, with an overall kappa of 0.362. Kappa by diagnostic category was 0.483, 0.178, 0.258, and 0.520 for NHGUC, AUC, SHGUC, and HGUC, respectively. Both TM and TPS showed 100% specificity and PPV. TPS showed 43% sensitivity (38% by TM) and 70% accuracy (66% by TM). Disagreements with high clinical impact were 27%. Of the 100 cases, 52 were concurrent biopsy-proven HGUC. The detection rate of biopsy-proven HGUC was 43% by TPS (57% by TM). The rate of NHGUC was 54% by TPS versus 26% by TM. AUC rate was 23% by TPS (44% by TM). The PPV of the AUC category by TPS was 61% versus 43% by TM. The survey showed 33% overall satisfaction.

Conclusions:

TPS shows adequate precision for NHGUC and HGUC, with low interobserver agreement for other categories. TPS significantly increased the clinical significance of AUC category. Refinement and widespread application of TPS diagnostic criteria may further improve interobserver agreement and the detection rate of HGUC.

Practice Patterns in Urinary Cytopathology Prior to the Paris System for Reporting Urinary Cytology

CONTEXT.—

The Paris System for Reporting Urinary Cytology has been disseminated since its inception in 2013; however, the daily practice patterns of urinary tract cytopathology are not well known.

OBJECTIVE.—

To assess urinary tract cytopathology practice patterns across a variety of pathology laboratories to aid in the implementation and future update of the Paris System for Reporting Urinary Cytology.

DESIGN.—

A questionnaire was designed to gather information about urinary tract cytopathology practices and mailed in July 2014 to 2116 laboratories participating in the College of American Pathologists interlaboratory comparison program. The participating laboratories' answers were summarized.

RESULTS.—

Of the 879 of 2116 laboratories (41%) that participated, 745 (84.8%) reported processing urinary tract specimens in house. The laboratories reported processing various specimen types: voided urine, 735 of 738 (99.6%); bladder washing/barbotage, 639 of 738 (86.6%); and catheterized urine specimens, 653 of 738 (88.5%). Some laboratories used multiple preparation methods, but the most commonly used preparation techniques for urinary tract specimens were ThinPrep (57.4%) and Cytospin (45.5%). Eighty-eight of 197 laboratories (44.7%) reported preparing a cell block, but with a low frequency. Adequacy criteria were used by 295 of 707 laboratories (41.7%) for voided urine, and 244 of 707 (34.5%) assessed adequacy for bladder washing/barbotage. More than 95% of the laboratories reported the use of general categories: negative, atypical, suspicious, and positive. Polyomavirus was classified as negative in 408 of 642 laboratories (63.6%) and atypical in 189 of 642 (29.4%). One hundred twenty-eight of 708 laboratories (18.1%) performed ancillary testing, and of these, 102 of 122 (83.6%) reported performing UroVysion.

CONCLUSIONS.—

Most laboratories use the ThinPrep method followed by the Cytospin technique; therefore, the criteria published in The Paris System for Reporting Urinary Cytology, based mostly on ThinPrep and SurePath, should be validated for Cytospin, and relevant information should be included in the revised edition of The Paris System for Reporting Urinary Cytology.

A Quest for Accuracy: Evaluation of The Paris System in Diagnosis of Urothelial Carcinomas

INTRODUCTION

Urine cytology is an important screening tool of patients for urothelial carcinoma (UC) and follow-up of patients with treated disease. Ease of procurement, cost-effectiveness, and lower turnaround time are the major advantages.

OBJECTIVE

To compare current system of reporting (CSR) at our institute with The Paris System (TPS) and analyze utility of urine cytology based on TPS reporting in correlation with urine culture and histopathology.

MATERIALS AND METHODS

One-year retrospective study of 90 cases was undertaken wherein cases presenting with painless hematuria and clinically suspicious of UC were included. Urine cytology slides were reviewed and reported with TPS guidelines. These findings were correlated with histopathological diagnosis and urine culture as indicated. Statistical analysis was done using SPSS 17 software.

RESULTS

With TPS guidelines, 11.1% and 5.6% cases were reported as high-grade UC (HGUC) and low-grade urothelial neoplasm (LGUN), respectively. Suspicious for HGUC category included 17.8% of cases. The rate of reporting "atypical urothelial cells (AUC)" was significantly lower (11.1%) with TPS on comparison with CSR (16.7%). Histopathological correlation of positive predictive value for HGUC was better (100%) on using TPS when compared with CSR (64.3%). Among 11 cases with microbial growth on urine culture, 9.1% were reported as atypical. Sensitivity and accuracy of TPS in detecting UC were 83.3% and 86.52%, respectively. Both were higher when compared with CSR.

CONCLUSION

In comparison to CSR, criteria of TPS limit the AUC category and enhance the sensitivity and accuracy of detecting HGUC. Adopting TPS for urinary cytology will ensure uniformity and accuracy of HGUC diagnosis.

A Review of Urine Ancillary Tests in the Era of the Paris System

Aside from its diagnostic importance, urinary tract endoscopy is an uncomfortable, expensive, and time-consuming procedure. Patients with a history of urothelial carcinoma remain at an increased risk for recurrence and the development of de novo disease; most have had exposure to carcinogenic risk factors for decades prior to their first diagnosis that have bathed the entire urothelial tract. Consequently, monitoring these patients over their lifetime has made urothelial carcinoma one of the most expensive cancers for the US healthcare system. This expense has provided a financial incentive for academic and commercial groups to develop a test with a sufficient negative predictive value to reduce the frequency of surveillance procedures. Slide-based tests require a separate slide prepared from a split urine sample or from an additional urinary tract specimen. This process can place an additional burden on the laboratory due to changes in the workflow, especially if the split specimens need to be stored until a cytologic diagnosis is rendered (i.e., when used as a reflex test). Importantly, slide-based tests allow for the result to be directly correlated with cytomorphologic findings; however, these tests require the cells of interest to be present. Thus, slide-based tests suffer from the same sensitivity issues as urinary tract cytology. In contrast, slide-free tests do not require an additional slide to be prepared, and laboratory testing may be centralized to a core facility or performed on-site. Some tests detect the expression of altered or abnormally expressed subcellular material (proteins, DNA, etc.) in urothelial neoplasms, which are found in tumor cells and/or in the urine specimen when the proteins are either excreted or leaked from degenerating tumor cells. Slide-free tests may also be developed into point-of-care tests, meaning that the result may be available to the urologist but not to the cytopathologist. Since these proteins are often disassociated from the tumor cells that produce them, such tests may have a positive result even if tumor cells are absent in the tested specimen. Here we review critical concepts as well as several ancillary tests that have been developed for urinary tract specimens.

Utility of The Paris System for Reporting Urinary Cytology in upper urinary tract specimens

INTRODUCTION

Diagnosing upper urinary tract (UUT) lesions using cytology has been historically difficult because of a lack of standardized terminology, cytomorphologic criteria, and the presence of instrumentation artifact. The goal of The Paris System for Reporting Urinary Cytology (TPSRUC) was to provide standardized terminology and cytomorphologic criteria. The aim of this study was to evaluate the utility of TPSRUC in UUT cytology specimens at our institution.

MATERIALS AND METHODS

Single ThinPrep archival slides from 30 UUT cytology cases with corresponding histological follow-up were reviewed using TPSRUC. Those results were compared with the original cytology diagnoses.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for high-grade urothelial carcinoma (HGUC) using TPSRUC were 71%, 100%, 100%, and 71%.

CONCLUSIONS

The TPSRUC was reliable at identifying HGUC. These data showed that this system had a lower sensitivity (71% versus 100%) and NPV (71% versus 100%) for UUT specimens compared with original cytology diagnoses. TPSRUC had a sensitivity and specificity that were comparable to reported overall sensitivity and specificity of UUT cytology for detection of HGUC. A major cause of discrepancy with TPSRUC was the classification of urine samples (n = 8) from histologically proven HGUC cases as only atypical (n = 6) or negative (n = 2), mainly owing to nuclear hypochromasia rather than hyperchromasia. Thus, hyperchromasia, a criteria used in TPSRUC, may not be as relevant in UUT specimens.

A Single Institutional Experience With the Paris System for Reporting Urinary Cytology: Correlation of Cytology and Histology in 194 Cases

OBJECTIVES

The Paris System for Reporting Urinary Cytology (TPS) is designed to standardize the criteria and terminology used in urinary tract cytology reporting. The aim of this study was to evaluate the impact of implementing TPS and to analyze the correlation with follow-up biopsies in order to assess its reproducibility.

METHODS

Urinary tract cytology specimens with follow-up biopsies over a 2-year period were reviewed and reclassified according to TPS criteria. Surgical follow-up diagnoses were correlated with the initial cytology diagnoses and TPS interpretations, and the results were compared.

RESULTS

Applying TPS in comparison to our previous reporting system resulted in fewer cases in the atypia category (11.8% vs 24.2%) and higher specificity, accuracy, and predictive value. We observed acceptable interobserver agreement in diagnostic categories of this reporting system.

CONCLUSIONS

TPS improves the overall performance of urinary tract cytology by standardizing the criteria and terminology.

The Paris System for Reporting Urinary Cytology: early review of the literature reveals successes and rare shortcomings

The Paris System for Reporting Urinary Cytology (TPS) provides recommendations for the diagnosis of urinary tract cytology (UTC) specimens and has found acceptance on an international level. Since the official release of TPS in 2016, numerous research studies have been published analyzing its impact. This review summarizes the studies published since the release of TPS, highlighting areas in which TPS has performed well and other areas in which TPS may need improvement.

Improved correlation of urinary cytology specimens using The Paris System in biopsy-proven upper tract urothelial carcinomas

BACKGROUND

Urine cytology specimens are essential for screening and monitoring high-grade urothelial carcinomas. However, inconsistent reporting and equivocal diagnostic categories have remained a challenge. The Paris System for Reporting Urinary Cytology (TPS) was developed to provide clear cytomorphologic criteria for urine cytology specimens. Significant correlation between the surgical biopsy diagnosis (SD) and TPS diagnosis (PD) has been established in lower urothelial tract carcinomas, but to the authors' knowledge limited information is available regarding upper urinary tract carcinomas.

METHODS

A total of 56 cytology specimens from 35 patients within 90 days of an SD of upper urinary tract carcinoma were included. Cytology was re-reviewed and assigned a PD. The original diagnosis (OD) and PD were compared with the corresponding SD to determine which correlated best.

RESULTS

The PD corresponded to the SD in 35 of 56 cases (63%), which was greater than that for the OD and SD, which were concordant in 19 of 56 cases (34%). Both the OD and PD were concordant in 18 of 56 cases (32%), and neither corresponded in 20 of 56 cases (36%). A total of 27 of 33 cases of high-grade urothelial carcinoma/carcinoma in situ on SD (82%) were identified using the PD whereas only 15 cases (45%) were identified with the OD. The number of "atypical" diagnoses in the OD was reduced from 16 of 56 cases (29%) to 7 of 56 cases (13%) using the PD. Of the 14 of 56 "negative" OD (25%), only 4 remained after implementation of the PD. A diagnosis of low-grade urothelial neoplasm was established in 6 of 20 cases (30%) with the PD compared with 3 of 20 cases with the OD (15%).

CONCLUSIONS

The authors found that reclassification with TPS improved correlation with the SD compared with previous methodologies. Specifically, TPS increased the number of high-grade urothelial carcinoma diagnoses and decreased the number of equivocal or "atypical" diagnoses. Cancer Cytopathol 2018. © 2018 American Cancer Society.

High-grade urothelial carcinoma in urine cytology with jet black and smooth or glassy chromatin

BACKGROUND

Some high-grade urothelial carcinomas (UCs) in urine cytology can have jet black, smooth, or glassy chromatin, but to the authors' knowledge, the incidence and criteria for diagnosis are not well described. The current study was performed to define the incidence and appearance of high-grade UC in urine cytology in cytospin preparations with jet black and smooth or glassy chromatin.

METHODS

Cytospin preparations from 331 cases with biopsy follow-up (230 benign/low-grade UCs and 101 malignant UCs) were reviewed.

RESULTS

Cases with malignant cells with jet black and smooth or glassy chromatin were identified in a total of 60 cases (59.4% of all malignancies). These comprised 18 carcinoma in situ cases, 28 high-grade papillary UCs, 8 invasive UCs, 3 squamous cell carcinomas, 2 adenocarcinomas, and 1 melanoma. Of the 93 high-grade UCs, 51 (54.8%) had cells with either jet black and smooth or glassy chromatin. These cells were the only type of malignant cell in 6 of 101 cases (5.9%). All cases had at least 50 cells with jet black nuclei. Nuclei with jet black and smooth chromatin often were smaller than normal urothelial cells, often but not always elongate, had irregular nuclear outlines including pointed areas, and usually were accompanied by necrosis. Cells with glassy chromatin often were larger than normal urothelial cells, had rounder but still irregular nuclei, and also had frequent necrosis.

CONCLUSIONS

Malignant urothelial cells in urine cytology with jet black chromatin are common and can be diagnosed as "positive for malignancy" based on their irregular nuclear outline, increased cellularity (≥50 abnormal cells), and frequent necrosis. Cancer Cytopathol 2018;126:64-8. © 2017 American Cancer Society.