Cytohistological correlation of urine cytology in a tertiary centre with application of the Paris system

Impact of implementing the first edition of the Paris system for reporting: A systematic review and meta-analysis

Urine cytology is a noninvasive, widely used diagnostic tool for screening and surveillance of genitourinary tract neoplasms. However, the absence of unified terminology and clear objective morphological criteria limits the clinical benefit of urine cytology. The Paris System for Reporting Urine Cytology (TPS) was developed with the goal of standardizing reporting and improving urine cytology performance in detecting high-grade malignancy (HGM). We aimed to evaluate potential effects of TPS on improving urine cytology diagnostic performance and clinical utility by conducting a systematic review and meta-analysis. We searched six electronic databases to identify cross-sectional and cohort studies written in English assessing the accuracy of urine cytology in detecting genitourinary tract malignancies of patients under surveillance or with clinical suspicion of malignancy from January 2004 to December 2022. We extracted relevant data from eligible studies to calculate relative distribution of cytology diagnostic categories; ratio of atypical to HGM cytology diagnosis; and risk of HGM (ROHGM) and HGM likelihood ratio (HGM-LR) associated with cytology diagnostic categories. We used a generalized linear mixed model with logit transformation to combine proportions and multilevel mixed-effect logistic regression to pool diagnostic accuracy measurements. We performed meta-regression to evaluate any significant difference between TPS and non-TPS cohorts. We included 64 studies for 99,796 combined total cytology samples, across 31 TPS and 49 non-TPS cohorts. Pooled relative distribution [95% confidence interval (CI)] of negative for high-grade urothelial carcinoma (NHGUC)/negative for malignancy (NM); atypical urothelial cells (AUC); suspicious for high-grade urothelial carcinoma (SHGUC)/suspicious for malignancy (SM); low-grade urothelial neoplasm (LGUN); and HGM categories among satisfactory cytology cases were 83.8% (80.3%-86.9%), 8.0% (6.0%-10.6%), 2.2% (1.4%-3.3%), 0.01% (0.0%-0.1%), and 4.2% (3.2%-5.5%) in TPS versus 80.8% (76.8-2.7%), 11.3% (8.6%-14.7%), 1.8% (1.2%-2.7%), 0.01% (0.0%-0.1%), and 3.3% (2.5%-4.3%) in non-TPS cohorts. Adopting TPS classification resulted in a significant increase in the frequency of NHGUC and a reduction in AUC cytology diagnoses, respectively. The AUC/HGM ratio in TPS cohort was 2.0, which showed a statistically significant difference from the atypical/HGM ratio of 4.1 in non-TPS cohort (p-value: 0.01). Moreover, the summary rate (95% CI) of LGUN called AUC on cytology significantly decreased to 20.8% (14.9%-28.3%) in the TPS compared with 34.1% (26.4%-42.8%) in non-TPS cohorts. The pooled ROHGM (95% CI) was 20.4% (6.2%-50.0%) in nondiagnostic (NDX), 15.5% (9.6%-24.2%) in NHGUC, 40.2% (30.9%-50.2%) in AUC, 80.8% (72.9%-86.8%) in SHGUC, 15.1% (5.7%-34.3%) in LGUN, and 91.4% (87.3%-94.3%) in HGM categories in TPS studies. NHGUC, AUC, SHGUC, and HGM categories were associated with HGM-LR (95% CI) of 0.2 (0.1-0.3), 0.9 (0.6-1.3), 6.9 (2.4-19.9), and 16.8 (8.3-33.8). Our results suggest that TPS 1.0 has reduced the relative frequency of AUC diagnosis, AUC/HGM ratio, and the frequency of LGUNs diagnosed as AUC on cytology. Adopting this classification has improved the clinical utility of SHGUC and HGM cytology diagnoses in ruling in high-grade lesions. However, an NHGUC diagnosis does not reliably rule out the presence of a high-grade lesion.

Utility of Image Morphometry in the Atypical Urothelial Cells and High-Grade Urothelial Carcinoma Categories of the Paris System for Reporting Urinary Cytology

Introduction

Urinary cytology (UrCy) is highly sensitive to diagnosing high-grade urothelial carcinoma (HGUC) but cannot predict muscularis propria invasion. Further, the atypical urothelial cell category (AUC) may have variable outcomes. Image morphometry (IM) may be a valuable adjunct technique in this setting. Hence, we evaluated IM in the AUC and HGUC categories to improve the diagnostic performance.

Materials and Methods

The following six nuclear parameters were evaluated by IM on 3150 cells: nucleo-cytoplasmic (N:C) ratio, nuclear area, diameter, perimeter, standard deviation of the nuclear area (SDNA; pleomorphism) and integrated density (ID; nuclear chromasia), using the ImageJ software, in three cohorts based on the histopathology outcome: 20 cases of AUC - benign non-neoplastic outcome (AUC-B); 22 cases of HGUC Muscle invasive (HGUC-MI) and 21 cases of HGUC non-muscle invasive (HGUC-MF).

Results

A retrospective analysis of urine cytology. The patient's ages ranged from 36 to 85 years, with a mean age of 60.6. The male-to-female ratio was 5.4:1. A total of 20 cases of AUC-B and 43 cases of HGUC were selected for IM analysis. HGUC cases had higher nuclear parameters than AUC-B, and HGUC-MI had higher SDNA, ID, diameter, and area than HGUC-MF. SDNA and ID predict muscularis propria invasion in HGUC.

Conclusions

Image morphometry successfully differentiates HGUC cases from benign non-neoplastic ones and might help to identify muscularis propria invasion in HGUC using a combination of nuclear parameters.

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.

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.

Large-scale longitudinal comparison of urine cytological classification systems reveals potential early adoption of The Paris System criteria

INTRODUCTION

Urine cytology is used to screen for urothelial carcinoma in patients with hematuria or risk factors (eg, smoking, industrial dye exposure) and is an essential clinical triage and longitudinal monitoring tool for patients with known bladder cancer. However, urine cytology is semisubjective and thus susceptible to issues including specimen quality, interobserver variability, and "hedging" towards equivocal ("atypical") diagnoses. These factors limit the predictive value of urine cytology and increase reliance on invasive procedures (cystoscopy). The Paris System for Reporting Urine Cytology (TPS) was formulated to provide more quantitative/reproducible endpoints with well-defined criteria for urothelial atypia. TPS is often compared to other assessment techniques to justify its adoption. TPS results in decreased use of the atypical category and better reproducibility. Previous reports comparing diagnoses pre- and post-TPS have not considered temporal differences between diagnoses made under prior systems and TPS. By aggregating across time, studies may underestimate the magnitude of differences between assessment methods.

MATERIALS AND METHODS

We conducted a large-scale longitudinal reassessment of urine cytology using TPS criteria from specimens collected from 2008 to 2018, prior to the mid-2018 adoption of TPS at an academic medical center.

RESULTS

Findings indicate that differences in atypical assignment were largest at the start of the period and these differences progressively decreased towards insignificance just prior to TPS implementation.

CONCLUSIONS

This finding suggests that cytopathologists had begun to utilize the quantitative TPS criteria prior to official adoption, which may more broadly inform adoption strategies, communication, and understanding for evolving classification systems in cytology.

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.

[How has the Paris System contributed to urine cytology? Evaluating the contribution of the Paris System to urine cytology. A comparative study of the Paris System and the Papanicolaou method in a tertiary centre]

INTRODUCTION AND OBJECTIVES

The Paris System (PS) has replaced the classical Papanicolaou System (PapS) in reporting urine cytology, due to its improved sensitivity and negative predictive value (NPV) without loss of specificity. Furthermore, it has enabled the risk of malignancy to be established in each cytological category. The aim of this study is to compare the Paris System with previous results and determine the changes in sensitivity, specificity, positive predictive value, NPV and risk of malignancy in our centre, MATERIALS AND METHODS: Evaluation of the diagnostic power of urine cytology by means of a retrospective cohort study, comparing two series of 400 cytological studies, one using the Papanicolaou System and the other the Paris System.

RESULTS

In the detection of high-grade urothelial carcinoma, Paris System has better specificity (93.82% PapS vs 98.64% PS; P=.001) and PPV (39.5% PapS vs 70.6% PS; P=.044) than Papanicolaou System, without changes in sensitivity (53.5% PapS vs 37.5% PS; P=.299) or NPV (96.4% PapS vs 94.8% PS; P=.183). The risk of malignancy for the atypical category increases from low to high levels (1.6% PapS vs 40.0% PS; P=.001); the other categories showed no significant statistical changes.

CONCLUSION

The Paris System improves specificity and positive predictive value and establishes a better indication of risk of malignancy for each category, enabling specific clinical management in each case.

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.

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

BACKGROUND

The Paris system (TPS) for Reporting Urinary Cytology provides a standardized reporting system whose main focus is the diagnosis of high-grade urothelial carcinoma (HGUC). We conducted a study to see the impact of The Paris System on our cytologic diagnoses with associated histology.

MATERIALS AND METHODS

We reviewed our pathology database regarding urinary specimens in the year before implementation of The Paris System and the year after. We gathered the data regarding cytologic diagnosis and concurrent/subsequent histology.

RESULTS

Over a 1-year period from 2016-2017, 486 urine cytology specimens were identified before implementation of The Paris System and diagnosed as follows: 83% benign/negative, 10% atypical, 2% suspicious, 5% HGUC, 0.2% low grade urothelial neoplasm (LGUN), and 0.2% unsatisfactory. Over a next 1-year period from 2017 to 2018, 602 specimens used TPS and diagnosed as follows: 85% negative for HGUC, 6% atypical, 3% suspicious, 4% HGUC, 0.17% LGUN, and 2% unsatisfactory. Although, not listed as a standardized category in The Paris System, our institution used "Negative for high-grade, cannot rule out low-grade urothelial neoplasm (NHL)" as a subcategory of Negative for HGUC. 4% of the cases fell into this category. Focusing on the Atypical category before TPS, histology was available in 15/49 (31%) cases. Of these, 40% had HGUC. Regarding the Atypical category after TPS, histology was available in 21/36 (58%) cases. Of these, 52% were HGUC. For the NHL category, concurrent histology was available in 13/26 (50%) cases. Of these, 67% were low grade urothelial neoplasms.

CONCLUSION

Our study showed that TPS lowered the rate of Atypical from 10% to 6%. After the implementation of TPS, Atypical corresponded to a higher rate of high-grade urothelial carcinoma. Also, the NHL subcategory had a high positive predictive value for diagnosing low grade urothelial neoplasms.

Urinary tract cytology: a cytologic-histopathologic correlation with The Paris System, an institutional study

INTRODUCTION

Urothelial carcinoma (UC) requires lifelong monitoring, commonly through urinary cytology and cystoscopy. Urine cytology has a relatively high sensitivity for detecting high-grade urothelial carcinoma (HGUC); however, its sensitivity for low-grade urothelial neoplasm (LGUN) is significantly lower with wide interobserver variability. The Paris System (TPS) was proposed to create standardized diagnostic categories with defined cytomorphologic criteria. We attempt to evaluate diagnostic efficacy of identifying UC using TPS through cytologic-histologic correlation.

MATERIALS AND METHODS

A retrospective search identified 170 cases of urine cytology cases with concurrent biopsies collected during a 2-year time period at University of Rochester Medical Center. Patient age, sex, smoking history, prior malignancy diagnoses, cystoscopy findings, specimen collection method, UroVysion results, and 1-year follow-up of surgical pathology cases were included.

RESULTS

Cytologic-histologic correlation was identified in 59% of cases, with 18% true positives and 41% true negatives. Discordant results were identified in 41% of cases; of these, 4% were false positives, 11% false negatives, 12% potential sampling bias, and 14% were low-grade urothelial carcinoma (LGUC). The analysis of this 2-year study finds a positive predictive value of urine cytology for HGUC to be 81%, a negative predictive value of 79%, a sensitivity of 61%, a specificity of 91%, and an accuracy of 79%.

CONCLUSIONS

Our results support TPS's ability to improve the reliability and accuracy of interpretations in urine cytology for HGUC. Nevertheless, additional studies are essential to improve the diagnostic accuracy of LGUN, and urine adequacy, in order to improve patient care and early detection, while identifying potential sampling bias.

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 in daily practice with emphasis on ancillary testing by multiprobe FISH

Aims

The Paris System (TPS) was introduced in the diagnostic routine with the goal to simplify and standardise diagnostic reporting of urinary cytology. The diagnostic categories of TPS are based on defined cytological criteria, with a focus on high-grade urothelial carcinoma (HGUC). While the categories ‘negative for HGUC (NHGUC)’ and ‘HGUC’ are straightforward, the categories ‘atypical urothelial cells (AUC)’ and ‘suspicious of HGUC (SHGUC)’ remain inconclusive. In this study, we evaluated the feasibility of TPS in daily practice with special emphasis on ancillary fluorescence in situ hybridisation (FISH) testing in the setting of TPS categories.

Methods

In a 19-month period, TPS was prospectively applied in the routine diagnostic setting on 3900 urinary cytology cases comprising bladder and upper urinary tract washings and voided urine specimens. Additionally, we analysed the results of the FISH assay UroVysion prospectively performed on a cohort of 128 cases enriched for AUC and SHGUC categories.

Results

The most frequently reported category was NHGUC (n=3496, 89.7%), followed by AUC (n=178, 4.6%), HGUC (n=155, 4%), SHGUC (n=61, 1.6%), low-grade urothelial neoplasia (n=6, 0.1%) and other malignancies (n=4, 0.1%). In the FISH cohort, 40/90 (44%) cases within the AUC category were FISH positive, consistent with urothelial neoplasia. In the SHGUC category, 16/21 (76%) cases were FISH positive.

Conclusions

When prospectively applying TPS in urinary cytology, inconclusive atypia accounts only for a small subset of cases. FISH additionally improves the stratification between reactive and malignant cells in the indeterminate AUC and SHGUC categories.

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.

[Aftercare of non-muscle invasive bladder cancer]

Tumor follow-up in patients with non-muscle invasive bladder cancer (NMIBC) is a weighing up between the morbidity associated with invasive diagnostics and the risk of tumor recurrence and especially progression. The risk stratification into low, intermediate, and high-risk tumors enables a risk-adapted follow-up. For individual estimation of the risk of progression and recurrence, risk calculators should be used. Follow-up is still based on cystoscopy, which is recommended lifelong for high and intermediate-risk tumors and for up to 5 tumor-free years for low-risk tumors. Urine cytology has a high sensitivity and specificity for high-risk tumors and is recommended in the follow-up care. There is currently no recommendation for any commercially available urinary marker due to inadequate evidence. For the clarification of synchronous and metachronous tumors of the upper urinary tract computed tomography (CT) urography or alternatively magnetic resonance (MR) urography is recommended.