Evaluation of the Paris System in atypical urinary cytology

Large-scale validation study of an improved semiautonomous urine cytology assessment tool: AutoParis-X

BACKGROUND

Adopting a computational approach for the assessment of urine cytology specimens has the potential to improve the efficiency, accuracy, and reliability of bladder cancer screening, which has heretofore relied on semisubjective manual assessment methods. As rigorous, quantitative criteria and guidelines have been introduced for improving screening practices (e.g., The Paris System for Reporting Urinary Cytology), algorithms to emulate semiautonomous diagnostic decision-making have lagged behind, in part because of the complex and nuanced nature of urine cytology reporting.

METHODS

In this study, the authors report on the development and large-scale validation of a deep-learning tool, AutoParis-X, which can facilitate rapid, semiautonomous examination of urine cytology specimens.

RESULTS

The results of this large-scale, retrospective validation study indicate that AutoParis-X can accurately determine urothelial cell atypia and aggregate a wide variety of cell-related and cluster-related information across a slide to yield an atypia burden score, which correlates closely with overall specimen atypia and is predictive of Paris system diagnostic categories. Importantly, this approach accounts for challenges associated with the assessment of overlapping cell cluster borders, which improve the ability to predict specimen atypia and accurately estimate the nuclear-to-cytoplasm ratio for cells in these clusters.

CONCLUSIONS

The authors developed a publicly available, open-source, interactive web application that features a simple, easy-to-use display for examining urine cytology whole-slide images and determining the level of atypia in specific cells, flagging the most abnormal cells for pathologist review. The accuracy of AutoParis-X (and other semiautomated digital pathology systems) indicates that these technologies are approaching clinical readiness and necessitates full evaluation of these algorithms in head-to-head clinical trials.

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.

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.

Usefulness of the Urine Methylation Test (Bladder EpiCheck®) in Follow-Up Patients with Non-Muscle Invasive Bladder Cancer and Cytological Diagnosis of Atypical Urothelial Cells—An Institutional Study

Urothelial bladder cancer is a heterogeneous disease and one of the most common cancers worldwide. Bladder cancer ranges from low-grade tumors that recur and require long-term invasive surveillance to high-grade tumors with high mortality. After the initial contemporary treatment in non-muscle invasive bladder cancer, recurrence and progression rates remain high. Follow-up of these patients involves the use of cystoscopies, cytology, and imaging of the upper urinary tract in selected patients. However, in this context, both cystoscopy and cytology have limitations. In the follow-up of bladder cancer, the finding of urothelial cells with abnormal cytological characteristics is common. The main objective of our study was to evaluate the usefulness of a urine DNA methylation test in patients with urothelial bladder cancer under follow-up and a cytological finding of urothelial cell atypia. In addition, we analyzed the relationship between the urine DNA methylation test, urine cytology, and subsequent cystoscopy study. It was a prospective and descriptive cohort study conducted on patients presenting with non-muscle invasive urothelial carcinoma between 1 January 2018 and 31 May 2022. A voided urine sample and a DNA methylation test was extracted from each patient. A total of 70 patients, 58 male and 12 female, with a median age of 70.03 years were studied. High-grade urothelial carcinoma was the main histopathological diagnosis. Of the cytologies, 41.46% were cataloged as atypical urothelial cells. The DNA methylation test was positive in 17 urine samples, 51 were negative and 2 were invalid. We demonstrated the usefulness of a DNA methylation test in the follow-up of patients diagnosed with urothelial carcinoma. The methylation test also helps to diagnose urothelial cell atypia.

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.

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.

Comparison of conventional and liquid-based cytology using The Paris System for Reporting Urinary Cytology

BACKGROUND

This retrospective study was conducted to compare the conventional cytospin method and ThinPrep liquid-based urinary cytology in diagnosing bladder cancer using The Paris System (TPS) of classification.

METHODS

We retrieved files for 2020, at the Cytopathology Department of Laiko Hospital, of urinary cases diagnosed according to TPS. Cytospin and ThinPrep slides were separately reviewed and new diagnoses were rendered, then compared with the original diagnosis and histology when available. Risk of high-grade malignancy (ROHM) for each TPS category was assessed, along with accuracy parameters of each method and their combination.

RESULTS

The study material comprised 100 cases of void urinary cytology classified as 20 high-grade urothelial carcinoma (HGUC = TPS5) cases, 20 of suspicion for HGUC (SHGUC = TPS4), 25 of atypical urothelial cells (AUC = TPS3), and 35 of negative for HGUC (NHGUC = TPS2). A single inadequate (TPS1) case and 4 of low-grade urothelial neoplasm (TPS6) were excluded as small in number. The ROHM was 95% for HGUC, 55% for SHGUC, 28% for AUC and 5.7% for NHGUC. Agreement with the original diagnosis was 86% for cytospin and 82% for ThinPrep. No significant differences were observed among the two techniques or their combination regarding sensitivity and specificity, with a mild advantage for cytospin. Interobserver reproducibility and repeatability were high.

CONCLUSION

No significant differences were found concerning sensitivity and specificity between cytospin and ThinPrep when applying TPS criteria. TPS is a reliable classification scheme for either conventional/cytospin or liquid-based cytology, or their combination.

Atypia in pulmonary cytology: A cytomorphometric analysis of the spectrum of changes between benign and malignant

BACKGROUND

Cytopathologists reviewing pulmonary specimens are expected to classify samples into clinically useful categories. Clinicians prefer reports to convey a definitively benign or definitively malignant diagnosis. Cytopathologists recognize a spectrum of morphologic features with increasing degrees of atypia between clearly benign and clearly malignant. A variety of terms are used to convey to clinicians how concerned a cytologist is that a malignancy maybe present. These terms include "atypia", "atypical" and "suspicious for malignancy", but have had variable meanings among cytopathologists and clinicians. Categorization schemes have been proffered to include standardization of terminology with many of these systems containing one or more intermediate categories.

METHODS

An electronic search of the University of Missouri cytology reporting system was made for all bronchial brushings specimens diagnosed using the Papanicolaou Society of Cytopathology System for Reporting Respiratory Cytology (PSCSR) between January 2019 and December 2019. Slides were reviewed to determine adequate cellularity and preparation quality. From those found to be adequately cellular and of good quality, four bronchial brushing specimens from each PSCSR category were randomly selected. For each case a slide was digitized and at least 70 of the most "atypical" cells were analyzed by the Aperio System for nuclear area and nuclear/cytoplasmic ratio. Distribution of measured parameters among categories was analyzed by the Kruskal-Wallis test.

RESULTS

During the study period, only the PSCSR categories "benign", "atypical" and "malignant" were recorded. A significant difference in distribution of nuclear/cytoplasmic ratio was seen between the "benign" and "atypical" categories but not between the "atypical" and "malignant" categories. The "atypical" category appeared to be bi-modal indicating that it could be divided into two categories, "atypical" and "suspicious for malignancy".

CONCLUSIONS

The categories "atypical" and "suspicious for malignancy" served to divide the spectrum of cytomorphologic changes between "benign" and "malignant" into clinically useful groups. The use of these categories is supported by cytomorphometric analysis of bronchial brushing specimens.

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).

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

Background:

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

Materials and Methods:

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

Results:

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

Conclusions:

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

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

CONTEXT.—

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

OBJECTIVE.—

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

DESIGN.—

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

RESULTS.—

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

CONCLUSIONS.—

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