Improved risk stratification for patients with high-grade urothelial carcinoma following application of the Paris System for Reporting Urinary Cytology

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.

Utility of The Paris System (TPS) for upper urinary tract cytopathology: correlation with histology follow-up and UroVysion fluorescence in situ hybridization (FISH) analysis

INTRODUCTION

The Paris System (TPS) provides a uniform reporting system of urine cytology based on well-defined cytologic criteria. Due to their rarity, there are limited data on the utility of TPS in upper urinary tract (UUT) lesions and follow-up histology of cases with abnormal cytology. We aimed to evaluate the utility of TPS for UUT lesions by correlating the cytologic diagnoses using TPS criteria with subsequent histology. Additionally, the diagnostic utility of UroVysion (Abbott) fluorescence in situ hybridization (FISH) was assessed.

MATERIALS AND METHODS

A total of 148 UUT cytology specimens were retrospectively identified (2018-2022). Cytologic interpretation was performed using TPS, and then correlated with the findings of concurrent or subsequent histologic specimens. The performance of UroVysion FISH was analyzed. Sensitivity and specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting high-grade urothelial carcinoma (HGUC) were determined.

RESULTS

Among 83 patients who had concurrent or subsequent histologic specimens, cyto-histologic discrepancy was seen in 7 cases (8.4%). The sensitivity, specificity, PPV, and NPV using TPS criteria for detecting HGUC were 87%, and 92%, 96.4%, and 73%, respectively. UroVysion FISH was performed in 21 patients with atypical cytologic findings. The sensitivity and specificity of UroVysion for detecting HGUC was 75% and 86%, respectively, while PPV and NPV were 86% and 75%, respectively.

CONCLUSIONS

In our experience, the application of TPS criteria for reporting upper urinary cytology was reliable at detecting UUT lesions, especially HGUC. UroVysion FISH was a valuable ancillary test for detecting HGUC of UUT.

Cytologic evaluation of upper urinary tract specimens: An institutional retrospective study using The Paris System for Reporting Urine Cytology second edition with histopathologic follow-up

OBJECTIVE

Cytologic evaluation of the upper urinary tract (UUT) can be challenging due to instrumentation artefacts. This study retrospectively reviewed UUT specimens using The Paris System for Reporting Urinary Cytopathology, second edition (TPS 2.0), compared it with the original reporting system (ORS) and correlated it with histopathologic follow-up.

METHODS

An institutional database was reviewed for the UUT biopsy/resection histopathologic specimens, and we included 52 UUT cytology specimens pertinent to these cases in the study. These specimens were blindly reviewed and reclassified using TPS 2.0. The correlation between TPS 2.0, ORS and histopathologic follow-up was assessed.

RESULTS

The UUT cytology specimens corresponded to 21 (40.4%) high-grade urothelial carcinoma (HGUC), 27 (51.9%) low-grade urothelial carcinoma (LGUC) and 4 (7.7%) benign cases on follow-up. For HGGC cases, the associated TPS categories included unsatisfactory (n = 1, 4.8%), negative for HGUC (NHGUC; n = 3, 14.3%), atypical urothelial cells (AUC; n = 6, 28.6%), suspicious for HGUC (SHGUC; n = 3, 14.3%) and HGUC (n = 8, 38.1%), while ORS categorised the specimens as unsatisfactory (n = 1, 4.8%), negative for malignant cells (NFMC; n = 3, 14.3%), AUC (n = 5, 23.8%), low-grade urothelial carcinoma (LGUC; n = 0, 0%), SHGUC (n = 5, 23.8%) and HGUC (n = 7, 33.3%). The risks of high-grade malignancy among cytologic categories were similar between ORS and TPS (p > 0.05). The majority of LGUC were classified as AUC similarly by ORS and TPS (55.6% vs. 59.3%).

CONCLUSIONS

Our study demonstrated comparable performance between TPS 2.0 and ORS for UUT cytology specimens. Cytological diagnosis of UUT specimens remains challenging, especially for LGUC.

Urinary IL-6 and IL-8 as predictive markers in bladder urothelial carcinoma: A pilot study

BACKGROUND

Cytokines are known to be a key a factor in numerous malignancies and to exert an important regulatory role in the tumor microenvironment. Interest has grown in understanding how cytokines modulate the tumor microenvironment and which cytokines may serve as markers of the tumor process; however, a complete picture of the cytokine landscape in bladder cancer remains unclear.

METHODS

Fresh urine specimens with sufficient volume were collected at random intervals. The urine concentrations of IL-8 (CXCL8), CCL18, and CXCL9 were determined using the standard commercially available enzyme immunoassay. The urine concentrations of IL-6 were determined using the high sensitivity enzyme immunoassay kit. Urinary cytokine concentrations were normalized with urinary creatinine concentrations.

RESULTS

Significantly elevated concentrations of IL-6 and IL-8 were detected in the urine from patients with urothelial carcinoma on follow-up compared to patients with benign follow-up. The presence of both IL-6 and IL-8 in the urine samples from the high grade urothelial carcinoma (HGUC) cohort revealed a clear discrimination when compared to samples from patients with benign follow-up. The presence of the combination of both IL-6 and IL-8 had a sensitivity of 90.0% and a specificity of 81.25%. Similar data were obtained when receiver operating characteristic analysis was performed on both IL-6 and IL-8 concentrations in the urine from patients with HGUC vs. the hematuria cohort.

CONCLUSIONS

The presence of IL-6 and IL-8 in urine specimens may have predictive value for urothelial carcinoma. However, a large longitudinal study is required to statistically eliminate confounding factors and support this theory.

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.

Limited Value of Bladder Wash Cytology During Follow-Up of Patients With Non-muscle Invasive Bladder Cancer

Aims We aimed to assess the performance of bladder wash cytology (BWC) in daily clinical practice in a pure follow-up cohort of patients previously diagnosed with non-muscle invasive bladder cancer (NMIBC). Materials and methods We analyzed 2064 BWCs derived from 314 patients followed for NMIBC (2003-2016). Follow-up investigations were performed using cystoscopy (CS) in combination with BWC. Patients with suspicious CS and/or positive BWC underwent bladder biopsy or transurethral resection. BWC was considered positive if malignant or suspicious cells were reported. Sensitivity (Sn) and specificity (Sp) were calculated for the entire cohort and separately for low-grade (LG) and high-grade (HG) tumors, and carcinoma in situ (CIS) subgroups. Results A total of 95 recurrences were detected, of which only three were detected by BWC alone. Overall, Sn and Sp of BWC were 17.9% and 99.5%, respectively. For LG disease, these numbers were 14.0% and 100%, and for HG disease, these were 22.2% and 99.1%, respectively. For patients with CIS at initial diagnosis, Sn and Sp were 11.0% and 71.4%, respectively. For isolated primary CIS, Sn was 50.0%, and Sp was 98.2%. Conclusion Routine use of BWC in the follow-up for NMIBC is of limited value even in HG tumors. In the presence of isolated primary CIS, adjunct BWC might be justified.

Nuclear membrane irregularity in high-grade urothelial carcinoma cells can be measured by using circularity and solidity as morphometric shape definitions in digital image analysis of urinary tract cytology specimens

BACKGROUND

The Paris System for Reporting Urine Cytology defines objective (elevated nuclear/cytoplasmic ratio ≥0.7) and subjective (nuclear membrane irregularity, hyperchromicity, and coarse chromatin) cytomorphologic criteria to identify conventional high-grade urothelial carcinoma (HGUC) cells. Digital image analysis allows quantitative and objective measurement of these subjective criteria. In this study, digital image analysis was used to quantitate nuclear membrane irregularity in HGUC cells.

METHODS

Whole-slide images of HGUC urine specimens were acquired, and HGUC nuclei were manually annotated using the open-source bioimage analysis software QuPath. Custom scripts were used to calculate nuclear morphometrics and perform downstream analysis.

RESULTS

In total, 1395 HGUC cell nuclei were annotated across 24 HGUC specimens (48.1 ± 6.0 nuclei per case) using both pixel-level and smooth annotation approaches. Nuclear membrane irregularity was estimated by calculating nuclear circularity and solidity. Annotating at pixel-level resolution artifactually increases nuclear membrane perimeter, thus smoothing is necessary to better approximate a pathologist's assessment of nuclear membrane irregularity. After smoothing, nuclear circularity and solidity discriminate between HGUC cell nuclei with visually apparent differences in nuclear membrane irregularity.

CONCLUSIONS

Nuclear membrane irregularity defined by The Paris System for Reporting Urine Cytology is inherently subjective. This study identifies nuclear morphometrics that visually correlate with nuclear membrane irregularity. HGUC specimens show intercase variation in nuclear morphometrics, with some nuclei appearing remarkably regular while others show marked irregularity. A small population of irregular nuclei generates most of the intracase variation in nuclear morphometrics. These results highlight nuclear membrane irregularity as an important, but not definitive, cytomorphologic criterion in HGUC diagnosis.

Perceptions of Paris: an international survey in preparation for The Paris System for Reporting Urinary Cytology 2.0 (TPS 2.0)

INTRODUCTION

An international panel of experts in the field of urinary cytopathology conducted a survey, supported by the American Society of Cytopathology, to seek opinions, gather evidence, and identify practice patterns regarding urinary cytology before and after the introduction of The Paris System for Reporting Urinary Cytopathology (TPS). Results from this survey were utilized in the development of the second edition of TPS (TPS-2.0).

MATERIALS AND METHODS

The study group, originally formed during the 2013 International Congress of Cytology, reconvened at the 2019 annual meeting of the American Society of Cytopathology. To prepare for the second edition of TPS, the group generated a survey that included 43 questions related to the taxonomy and practice of urinary cytology.

RESULTS

A total of 523 participant responses were collected, and 451 from 54 countries passed a qualifying screen. Three hundred ninety-four participants provided information about their work settings. Eighty-two percent (218/266) of responding participants use TPS. One hundred sixty-eight people who responded on their urinary cytology atypia rates reported an average decrease from 21.6% to 16%. Over three fourths of participants felt that the same criteria should be used for upper and lower tract interpretations and for instrumented and voided samples. There were varied opinions on addressing atypical squamous cells and suggestions for an expanded discussion of the issue to be included in TPS 2.0.

CONCLUSIONS

Results of the survey demonstrate strong support for TPS and show a decreased self-reported atypia rate in the laboratories using TPS. The majority of participants related that the criteria put forth for the reporting categories were user-friendly and applied with relative ease. The comment section of the survey included suggestions from the participants for further improvement of TPS. Results of this survey have been useful in fine-tuning and advancing TPS. They were considered along with recent literature to generate the second edition of TPS.

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.

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

Since the release of The Paris System for Reporting Urinary Cytology (TPS), the assessment of urine cytology specimens has primarily focused on the detection of high-grade urothelial carcinoma (HGUC) and carcinoma in situ (CIS). Fortunately, the malignant cells in these lesions tend to be loosely cohesive, resulting in the natural exfoliation of individual malignant cells into the urine. However, HGUC/CIS lesions occasionally exfoliate larger fragments which can be difficult to assess due to cellular overlap and fragment three-dimensionality. Furthermore, reactive benign urothelial fragments and fragments from low-grade urothelial neoplasms (LGUN) may also be seen in urine specimens and contain atypical cytomorphologic features. As a result, the significance of urothelial tissue fragments (UTFs) is often unclear. Herein, we discuss the literature on UTFs before and after the implementation of TPS, as well as strategies to help overcome this diagnostic challenge.

The Paris System for reporting urinary cytology improves the negative predictive value of high-grade urothelial carcinoma

Background

The Paris System (TPS) for reporting urinary cytology differs from conventional systems (CS) in that it focuses on the diagnosis of high-grade urothelial carcinoma (HGUC). This study investigated the impact of TPS implementation on the diagnostic accuracy of HGUC by comparing it with our institutional CS.

Methods

A total of 649 patients who underwent transurethral resection of bladder tumor (TURBT) between January 2009 and December 2020 were included in this study. Our institution adopted TPS to report urinary cytology in February 2020. The diagnostic accuracy of HGUC in preoperative urinary cytology was compared with the presence or absence of HGUC in resected specimens of TURBT before and after TPS implementation.

Results

After implementing TPS in urinary cytology, 89 patients were reviewed and compared with 560 patients whose urinary cytology was diagnosed by CS. TPS and CS for detecting HGUC had 56.0% and 58.2% sensitivity, 97.8% and 91.2% specificity, and 93.3% and 87.9% positive predictive values, respectively. There were no significant differences between TPS and CS in terms of sensitivity, specificity, and positive predictive value for HGUC (P = 0.83, 0.21, 1.00). On the other hand, the negative predictive value for HGUC using TPS was 80.0%, which was significantly higher than that of CS (66.4%, P = 0.04) The multivariate logistic regression analysis indicated that not using TPS was one of the independent predictive factors associated with false-negative results for HGUC (odds ratio, 2.26; 95% confidence interval, 1.08–4.77; P = 0.03).

Conclusion

In instances where urinary cytology is reported as negative for HGUC by TPS, there is a low probability of HGUC, indicating that TPS has a potential diagnostic benefit.

The Paris system classification for urinary cytology in patients under bacillus Calmette-Guerin treatment

BACKGROUND

The role of urinary cytology as a diagnostic test for the detection and surveillance of urothelial cancer is crucial. Intravesical bacillus Calmette-Guerin (BCG) is the appropriate therapeutic strategy for patients with high-grade urothelial carcinoma (HGCU) or in situ carcinoma. We investigate how applicable is the Paris System for reporting urinary cytology (TPS) and how accurate is urinary cytology, in patients who undergo intravesical BCG instillations.

METHODS

Our study contains urine samples from patients during the period January 1, 2017 to December 31, 2019. The inclusion criteria were patients with history of urothelial bladder carcinoma who had been treated with intravesical BCG instillation and cytology was followed by histology. We report our results and estimate the risk of high-grade malignancy (ROHM) for each TPS category and cytology accuracy.

RESULTS

Four hundred thirty-eight samples corresponding to 146 patients fulfilled the criteria to be included in the study. There were 2 inadequate, 118 negative for high-grade urothelial carcinoma (NHGUC), 14 atypical urothelial cells (AUC), 6 suspicious for high-grade urothelial carcinoma (SHGUC), and 6 cases HGUC. Corresponding histology assessment has shown that the ROHM amounted to 0 for inadequate, 3.4% for NHGUC, 57% for AUC, 100% for SHGUC and HGUC. Sensitivity was 50%, specificity 100%, PPV 100%, NPV 91%, and accuracy 91.7%, considering inadequate, NHGUC and AUC as negative and SHGUC and HGUC as positive result. However, considering AUC a positive result, the accuracy parameters were different; sensitivity 83.3%, specificity 95%, PPV 76.9%, NPV 96.67%, and accuracy 93%.

CONCLUSION

The Paris system for reporting urinary cytology can be safely applied to patients during follow-up after BCG intravesical administration.

We'll always have Paris The Paris System for Reporting Urinary Cytology 2022

Following the amazing acceptance of The Paris System for Reporting Urinary Cytology (TPS), the second edition (TPS 2.0) was inevitable. Based on new studies since the publication of the first edition, diagnostic criteria are refined, and pitfalls discussed. In addition to reinforcing the mandate that the focus of diagnostic urinary cytology is the detection of high-grade urothelial carcinoma, other issues are addressed. Low-grade lesions are included in the category of negative for high-grade urothelial cancer. The rationale for that decision is strongly supported by evidence from the authors' experiences as well as the recent literature. A new chapter on urine cytology of the upper tract, a rarely addressed topic, explores the challenges involved. Furthermore, the issue of cellular degeneration is discussed in the criteria of all diagnostic categories. Most importantly, data defining the risk of high-grade malignancy (ROHM) for each diagnostic category informs clinical management. The 65 authors are recognized authorities from 33 countries, attesting to the global impact of TPS 2.0.

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.

Indeterminate atypia in urinary tract cytology: Does it really matter?

The study of atypia in urinary cytology has been ongoing for decades but most studies have focused primarily on test performance in patients with concurrent biopsies and/or limited follow-up periods. While these data are useful, many studies fail to consider patient factors that may alter the pretest probability, which can subsequently affect test performance. An isolated diagnosis of malignancy in urinary cytology usually has a high positive predictive value and allows a urologist to conduct a rigorous workup of the patient to establish a tissue diagnosis. However, it is less certain how an atypical diagnosis impacts patient care, given that many patients have a history of bladder cancer and are already under surveillance with cystoscopy at regular screening intervals. Furthermore, a discrete negative urine cytology is unlikely to allow a patient to forego a cystoscopy procedure due to limitations in the sensitivity of urine cytology. Over the last several years, the introduction of The Paris System for Reporting Urinary Cytology (TPS) has improved the predictive value of atypical diagnoses, but additional studies are needed to evaluate the performance of these diagnoses in specific clinical situations. Such data could better inform urologists on how to manage patients with atypical diagnoses. This review discussed the diagnosis of atypia in urinary cytology and the impact of such a diagnosis in various clinical contexts.

Comparison of Diagnostic Performances of Urine Cytology Before and After the Use of The Paris System Criteria: An Institutional Experience from Turkey

Background:

Urine cytology remains to be the test of choice in the detection of high-grade urothelial carcinomas (HGUC) due to its favorable sensitivity. However, a significant rate of cases is reported under atypical/indeterminate categories, which result in a decrease in its specificity. Providing standardized cytologic criteria, one of the aims of The Paris System (TPS) is to reduce the use of indeterminate diagnoses and provide a higher predictive value in these categories.

Aims:

We compared the diagnostic performances of TPS and our original reporting system, and also investigated the interobserver reproducibility of the cytologic criteria used.

Materials and Methods:

A total of 386 urine samples were reviewed retrospectively. Original cytologic diagnoses have been made using similar cytologic features proposed by TPS. All slides were recategorized after the use of the cytologic criteria as described by TPS guideline.

Results:

After TPS, specificity of the test increased from 39.6% to 63.5, sensitivity decreased from 92.5% to 88.8%, and diagnostic accuracy increased from 63.6% to 75%. The use of negative category increased threefold. Frequencies of indeterminate categories of atypical urothelial cells (AUC) and suspicious for HGUC (SHGUC) decreased by 36% and 56.5%, respectively. A subsequent detection of HGUC after AUC and SHGUC categories increased by 38% and 64%, respectively. Interobserver agreement for TPS categorization was 39%.

Conclusions:

TPS improved diagnostic accuracy of urine cytology by reducing the use of indeterminate categories, and resulted in increase in their predictive value for subsequent diagnosis of HGUC. However, reproducibility of diagnostic categories seemed to be imperfect.

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.

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.

Educational Case: Urothelial Carcinoma: An Overview of Pathologic Diagnosis

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

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.

A review of upper urinary tract cytology performance before and after the implementation of The Paris System

Urinary cytology (UC) is one of the primary diagnostic modalities used for the screening and surveillance of urothelial carcinoma. Despite its widespread use, UC has suffered from a lack of standardized or reproducible criteria and wide interobserver variability, particularly of the designation of atypical urothelial cells. The Paris System for Reporting Urinary Cytology (TPS), published in 2016, aimed to provide a standardized approach for evaluating UC by creating diagnostic categories with specific cytomorphologic criteria. Recent studies have primarily investigated the application of TPS on lower urinary tract specimens and have mostly shown that TPS implementation has improved the performance of UC specimens. Only a few studies have reported the impact of TPS on upper urinary tract (UUT) cytology. Additionally, there is uncertainty as to which cytological features are most predictive of high-grade urothelial carcinoma (HGUC) in the UUT. This review summarizes the literature regarding the utility and performance of UUT cytology and highlights findings before and after the implementation of TPS.

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.

A review of urinary cytology in the setting of upper tract urothelial carcinoma

Urothelial carcinomas of the upper urinary tract (UUT) are uncommon. Cytological examination of voided urine or washings from the UUT has been part of the standard workup for upper tract urothelial carcinoma (UTUC); however, its value remains controversial. The lack of uniform terminology and specific diagnostic criteria could also have contributed to the inferior performance of urinary cytology for detecting UTUC. The Paris System for Reporting Urinary Cytology (TPS) has provided a standardized reporting system for urinary cytology specimens with clearly defined cytomorphologic diagnostic criteria and found acceptance on an international level after its implementation in 2016. Recent studies have shown that TPS has led to improved diagnostic performance of urinary cytology; however, most of these studies had focused on the evaluation of lower urinary tract cytology specimens. Only a limited number of new research studies have analyzed the effect of TPS when applied to UUT cytology specimens. In the present report, we have summarized the current understanding and utility of UTUC, including its molecular biology, and reviewed the current literature.

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.

Urine cytology suspicious for urothelial carcinoma: Prospective follow-up of cases using cytology and urine biomarker-based ancillary techniques

BACKGROUND

Urine cytology results that are suspicious for urothelial carcinoma (UC) are challenging. The objective of this study was to elucidate the clinical significance of such results in patients who have a negative cystoscopy.

METHODS

In this prospective study, 83 patients who had urine cytology that was suspicious of UC and a negative cystoscopy underwent a second cystoscopy and urine evaluation by cytology, UroVysion fluorescence in situ hybridization (FISH) assay, FGFR3 (fibroblast growth factor receptor 3) and TERT (telomerase reverse transcriptase) mutations and an 8-gene expression classifier (GEC). Results from all techniques were compared with patients' clinical outcomes.

RESULTS

The presence of tumor was identified in 41% of patients; of these, 82% had tumors identified at their second evaluation (76% high-grade [HG] tumors), and 18% had tumors identified at a later follow-up (50% were HG tumors). After The Paris System for Reporting urinary Cytology (TPS) reclassification, 53 cytology results still had an indeterminate diagnosis (13 were suspicious for HGUC, and 40 had atypical urothelial cells (AUCs)]. Complete results from second evaluations using urine cytology, cytology-TPS, FISH, and GEC were available for 6 cases that were suspicious for HGUC and 34 cases that had AUCs. The sensitivity of these techniques to detect HG tumors in cases that were suspicious for HGUC was 100%, except for cytology-TPS, for which the sensitivity was 50%. The sensitivity of cytology and cytology-TPS to detect HG tumors in cases with AUCs was 33%, whereas the sensitivity of fluorescence in situ hybridization and GEC in these cases was 83% and 75%, respectively, to detect HG tumors at the second evaluation.

CONCLUSIONS

The current results indicate the relevant clinical significance of indeterminate urine cytology findings and strongly suggest the use of complementary evaluations by urine biomarker-based, ancillary techniques to elucidate their significance.

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.

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.

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.

Diagnostic Advances in Urine Cytology

The utility of urine cytology has shifted from the identification of red blood cells, crystals, or parasites to its currently used role of detection of cancer cells exfoliated in urine samples. A variety of ancillary tests have been developed to complement the diagnostic ability of urine cytology. Furthermore, urine testing will continue to evolve as the pathogenesis of genitourinary tract diseases in depth is understood. This article focuses on the diagnostic advances in urine cytology from the cytomorphological perspective, past and current reporting schemes, and the application of ancillary testing in urine samples.

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.

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.