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.

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.

Are we on track for diagnosing high-grade urothelial carcinoma with a minimum quantity of five malignant cells in lower tract specimens? Critical analysis of The Paris System Quantitation Criteria

BACKGROUND

The Paris System for Reporting Urinary Cytology (TPS) has gained universal acceptance as the standard for reporting urine cytology requiring at least 5-10 malignant cells to diagnose high-grade urothelial carcinoma (HGUC) in lower and upper urinary tract specimens, respectively. These quantitation criteria are still subject to discussion, and this study specifically aims to validate the quantitation criterion of HGUC in lower urinary tract.

DESIGN

The authors reviewed two cohorts of lower urinary tract cases. The first cohort consisted of 100 liquid-based ThinPrep slides with the diagnosis of HGUC having positive histology on concurrent or follow-up biopsies within 3 months. The second cohort was 36 HGUC cases with negative histology on concurrent biopsies and within 3 months. The number of high-grade cells (HGCs) meeting the TPS qualitative criteria were counted under the light microscope driven in a grid-like manner.

RESULTS

The first 100 urine samples showed five cases (5.0%) with three HGCs, three cases (3.0%) had four HGCs, five cases (5.0%) showed five HGCs, and 25 cases (25.0%) had between 6-10 HGCs. The risk of high-grade malignancy (ROHM) in cases with five or more HGCs was 100%, whereas those with three HGCs was 60.0%. The second cohort of HGUC was considered "positive" despite a negative histology.

CONCLUSION

This study confirms that quantitation is an essential key to diagnose HGUC. The current TPS criterion of a minimum of five malignant cells in lower tract is robust with a ROHM of 100%. Diagnosing HGUC with less than five HGCs runs the risk of lowering the ROHM.

5-Aminolevulinic acid-based photodynamic diagnosis for detection of urothelial carcinoma cells in bladder washing sediment suspension: A pilot study

BACKGROUND

Bladder cancer is a common malignant disease in developed countries. Early detection of malignancy is important using urine cytology. The 5-aminolevulinic acid (ALA)-based photodynamic diagnosis (ALA-PDD) has not been routinely applied in urine cytology analysis yet, although it has been well accepted for tumor lesion marking in cystoscopy.

METHODS

A total of eight volunteers were enrolled in this study. The cells of sediment suspension from bladder washing fluid and random urine were stained by ALA-induced protoporphyrin IX (ALA-PpIX) and the fluorescent intensity of ALA-PpIX was analyzed by ImageJ.

RESULTS

The cutoff value of fluorescent intensity was 90.260 per pixel. The proposed protocol provided an objective fluorescent intensity for evaluation. Sensitivity was 0.931 and specificity was 1.000.

CONCLUSIONS

The staining procedure applied was ALA-PpIX for suspicious cells in the cellular suspension from bladder wash fluid and random urine. ImageJ was applied to the objective measurement for the fluorescent intensity of the stained cells. The cutoff value for the positive result was 90.260 per pixel. Therefore, the protocol proposed in this study provides a potential means to enhance accuracy for urine cytology analysis.

Analysis of false-negatives in exfoliative cytology in oral potentially malignant disorders: A retrospective cohort study

INTRODUCTION

Keratinized lesions have been a conceivable false-negative (FN) factor in oral exfoliative cytology (OEC); however, other factors are poorly analyzed. In this study, we aimed to identify the factors influencing the accuracy of OEC and FNs focusing on the lesion characteristics, patient background, and surgeon factors in oral potentially malignant disorders (OPMD).

MATERIAL AND METHODS

We retrospectively studied 44 patients who underwent both OEC and histopathological diagnosis. Sensitivity, specificity, FN rate, false-positive (FP) rate, and prevalence of both methods were compared. Similarly, accuracy indices were compared among clinical diagnosis groups (leukoplakia vs. other diagnosis). The association between patient and surgeon-related factors influencing FN OEC results were investigated using Fisher's exact test and a multiple logistic regression analysis.

RESULTS

Overall, the sensitivity; specificity; and FN, FP, and prevalence rates of OEC were 31.8%, 82.1%, and 68.8%, 17.9%, and 36.4%, respectively. Leukoplakia was significantly more common in clinical diagnosis (P = 0.007) with sensitivity, specificity, and FN rates of 20.0%, 95.2%, and 80.0%, respectively. Contrarily, non-keratinized lesions had sensitivity, specificity, and FN of 83.3%, 85.7%, and 16.7%, respectively. In the prevalent group, leukoplakia and anucleate squamous cells were significantly associated with FN cases (P = 0.013, P = 0.050). On multivariate analysis in OEC negative patients, age ≤64 (P = 0.050) and location on the tongue (P = 0.047) was independently associated with FNs.

CONCLUSION

FN of OEC was conceivable to be due to poor deep-seated cell sampling, which was associated with leukoplakia, age, and location. Therefore, these factors may be considered in the evaluation of OEC results.

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 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.

Application of the Paris Reporting System for Urine Cytology: The Three-Year Experience of a Single Tertiary Care Institute in Thailand

INTRODUCTION

Urothelial carcinoma is one of the most common human cancers, both in Thailand and worldwide. Urine cytology is a screening tool used to detect urothelial carcinoma. The Paris System for Reporting Urinary Cytology (TPSRUC) was first published in 2016 to standardize the procedures, reporting, and management of urothelial carcinoma. Diagnostic categories include negative for high-grade urothelial carcinoma (NHGUC), atypical urothelial cells (AUCs), suspicious for HGUC (SHGUC), HGUC, low-grade urothelial neoplasm, and other malignancies.

MATERIAL AND METHODS

In a retrospective review, urine cytology specimens from 2016 to 2019 were reevaluated using the TPSRUC. The risk of high-grade malignant neoplasm (ROHM) for each diagnostic category was calculated. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of prediction of high-grade malignant neoplasms were evaluated for cases with histological follow-up specimens.

RESULTS

In total, 2,178 urine cytology specimens were evaluated, of which 456 cases had follow-up histological specimens. The ROHM in each diagnostic category was as follows: NHGUC, 17.4%; AUC, 49.9%; SHGUC, 81.2%; HGUC, 91.3%; and other malignant neoplasms, 87.5%. The sensitivity, specificity, PPV, NPV, and accuracy for high-grade malignant neoplasm prediction were 63%, 92.8%, 89%, 73.1%, and 78.5% when AUC was included as malignant in the comparison and 82.6%, 74.7%, 75.1%, 82.3%, and 78.5% when AUC was not considered malignant.

CONCLUSIONS

TPSRUC provides reliable results that are reproducible by different interpreters and is a helpful tool for the detection of HGUC.

Cytologically targeted next-generation sequencing: a synergy for diagnosing urothelial carcinoma

INTRODUCTION

Cytology and cystoscopy are used to detect urothelial carcinoma (UC), but together they still fail to detect some UC cases and are not suitable for screening asymptomatic individuals. Mutations are present in more than 98% of UC, mutations have therapeutic significance, and they can be detected by next generation sequencing (NGS) in urine samples. We review the role of NGS in UC detection.

MATERIALS AND METHODS

Comprehensive literature review on UC genetics, economics of NGS, and previous reports of UC detection by NGS.

RESULTS

The raw costs of NGS have decreased to about 14,000 base pairs per penny, making it appear economically feasible to use NGS widely. Reported NGS assays fall short of predicted sensitivity. Decreased sensitivity is attributed to a low frequency of mutant alleles in many urine samples. Attempts to increase the percentage of mutant alleles, by using cell-free urinary DNA, or by using cell sorting and microfluidics, have been unsuccessful or remain unproven. However, cytologic examination can immediately enable NGS: Urine cytologies with sufficient proportions of abnormal cells could be directly triaged to NGS with high sensitivity for UC detection. For cases with a low proportion of abnormal cells, cytologically targeted microdissection of cells for NGS should maintain sensitivity and decrease sequencing costs. Cytologically targeted urothelial cells for NGS could allow a screening test for low grade UC.

CONCLUSIONS

Cytology is immediately poised to allow NGS to improve the diagnosis of UC, allowing NGS to be an ancillary test for atypical cytologies, and potentially allowing a screening test for low-grade UC.

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.

Significant reduction of indeterminate (atypical) diagnosis after implementation of The Paris System for Reporting Urinary Cytology: A single-institution study of more than 27,000 cases

BACKGROUND

Urinary cytology is a noninvasive and cost-effective diagnostic and surveillance test in the clinical management of urothelial carcinoma (UC). The Paris System for Reporting Urinary Cytology (TPS), published in 2016, introduced definite diagnostic criteria aimed at improving performance in detecting high-grade UC (HGUC) and decreasing the indeterminate (atypical) diagnosis.

METHODS

The authors retrospectively reviewed and compared urinary cytology diagnoses reported between January 2013 and December 2014 (pre-TPS, 7658 cases) and between May 2016 and April 2018 (post-TPS, 20,026 cases) to assess the influence of TPS in their practice. The time in between was used as a learning period. Follow-up information and correlation with the UroVysion fluorescence in situ hybridization test were obtained when available.

RESULTS

Urinary cytology diagnoses pre-TPS included negative for UC (NUC) (n = 5293; 69.2%), atypical urothelial cells (AUC) (n = 2227; 29%), and suspicious/positive for HGUC (SHGUC/HGUC) (n = 138; 1.8%). Diagnoses post-TPS included negative for HGUC (NHGUC) (n = 18,507; 92.4%), AUC (n = 1237; 6.2%), and SHGUC/HGUC (n = 282; 1.4%). Comparing the pre-TPS and post-TPS periods, AUC diagnoses decreased from 29% to 6.2% (P < .00001), and the specificity and positive predictive value of AUC to detect HGUC significantly improved from 49% to 86% (P < .00001) and from 9% to 39% (P = .002), respectively. The correlation of an AUC diagnosis with a positive UroVysion test improved from 17% to 38% (P < .00001), whereas overall use of the UroVysion test was decreased.

CONCLUSIONS

Implementation of TPS resulted in a significant reduction in AUC diagnoses that had a superior correlation with a subsequent biopsy and a UroVysion test, resulting in potential reductions in test use and medical cost.

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.

Performance of an artificial intelligence algorithm for reporting urine cytopathology

BACKGROUND

Unlike Papanicolaou tests, there are no commercially available computer-assisted automated screening systems for urine specimens. Despite The Paris System for Reporting Urinary Cytology, there still is poor interobserver agreement with urine cytology and many cases in which a definitive diagnosis cannot be made. In the current study, the authors have reported on the development of an image algorithm that applies computational methods to digitized liquid-based urine cytology slides.

METHODS

A total of 2405 archival ThinPrep glass slides, including voided and instrumented urine cytology cases, were digitized. A deep learning computational pipeline with multiple tiers of convolutional neural network models was developed for processing whole slide images (WSIs) and predicting diagnoses. The algorithm was validated using a separate test data set comprised of consecutive cases encountered in routine clinical practice.

RESULTS

There were 1.9 million urothelial cells analyzed. An average of 5400 urothelial cells were identified in each WSI. The algorithm achieved an area under the curve of 0.88 (95% CI, 0.83-0.93). Using the optimal operating point, the algorithm's sensitivity was 79.5% (95% CI, 64.7%-90.2%) and the specificity was 84.5% (95% CI, 81.6%-87.1%) for high-grade urothelial carcinoma.

CONCLUSIONS

The authors successfully developed a computational algorithm capable of accurately analyzing WSIs of urine cytology cases. Compared with prior studies, this effort used a much larger data set, exploited whole slide-level and not just cell-level features, and used a cell gallery to display the algorithm's output for easy end-user review. This algorithm provides computer-assisted interpretation of urine cytology cases, akin to the machine learning technology currently used for automated Papanicolaou test screening.

A Modified Direct-Smear Processing Technique Employing Two-Step Centrifugation/Fixation Is Useful for Detecting High-Grade Urothelial Carcinoma

OBJECTIVE

To demonstrate the usefulness of a direct-smear processing technique employing two-step centrifugation/fixation processing (TSCFP) in the cytoscreening of high-grade urothelial carcinoma (HGUC).

STUDY DESIGN

Using the T24 HGUC cell line, we compared the cell yield and the morphological preservation of preparations concurrently processed by direct-smear, SurePath, ThinPrep, and TSCFP techniques. A total of 287 urine cytology cases subjected to TSCFP over a period of 6 years were reviewed and reclassified according to the Paris System for Reporting Urinary Cytology (PSRUC) and correlated with histology results.

RESULTS

TSCFP of T24 cells demonstrated good cell yield with a recovery rate of about 70%. Diagnostic features of HGUC, such as a high nuclear/cytoplasmic ratio and irregular/hyperchromatic chromatin, were better discovered in TSCFP smears than in smears prepared with the other methods. Cytological evaluation of 287 voided urine specimens revealed that the rate of unsatisfactory preparations was quite low (0.30%) and the overall sensitivity, specificity, and positive and negative predictive values for urothelial carcinoma were 0.719, 0.923, 0.973, and 0.462, respectively.

CONCLUSION

TSCFP was able to provide adequate preparations for detecting HGUC in urine cytology and could be considered as a promising processing method according to the principal purpose of PSRUC.