The Paris System for Reporting Urinary Cytology: the quest to develop a standardized terminology

A 2-center review of histopathology of variants of upper urinary tract urothelial carcinoma and their impact on clinical outcomes

INTRODUCTION

Similar to bladder cancer, about one third of upper tract urothelial carcinoma (UTUC) present variant histology (VH). We aim to evaluate the incidence, clinical characteristics and the impact on outcomes of VH in UTUC.

METHODS

We consecutively enrolled 77 patients treated between 2009 and 2022 by radical surgery for UTUC from a secondary and a tertiary referral center. A pathology review of all specimens was performed by 1 independent uropathologist for each center. We compared pure UTUC and UTUC with VH and the accuracy of endoscopic biopsy. Descriptive and comparative analysis was performed to assess the association with clinical characteristics and the Kaplan-Meier estimator to compare outcomes.

RESULTS

Median follow-up after surgery was 51 months. VH was present in 21/77 (28%) patients and 4/21 (19%) patients had multiple variants. The most frequent VH was squamous 12/21 (57%), followed by glandular 7/21 (33%) and micropapillary 3/21 variants (14%). Neuroendocrine carcinoma was present in 2 patients. Nested variant was found in 1 patient. Muscle invasive tumor (≥pT2) was present in 30/56 (54%) patients with pure UTUC and in 18/21 (86%) patients with VH (P < 0.05). Presence of carcinoma in situ was seen in 24/56 (43%) patients with pure UTUC and in 16/21 (76%) with VH (P < 0.05). Cumulative 8/56 (14%) with pure UTUC had a nonintravesical recurrence (6 patients with local and 2 distant recurrence) compared to 8/21 (38%) (3 local, 3 nodal, 2 distant) in the subgroup with VH (P < 0.05). Opposite effect was noted for bladder recurrence: 60% for pure UTUC vs. 29% for tumors with VH (P < 0.05). Review of preoperative endoscopic biopsy did not show the presence of VH in any patients. Differences in outcomes did not reach significance: 3yr-OS 63% vs. 42% (P 0.28) and 3yr-CSS 77% vs. 50% (P 0.7).

CONCLUSION

Almost a third of UTUC present VH. Presence of VH is related to more aggressive tumor characteristics and associated with unfavorable outcomes. Due to a higher rate of extravesical recurrences in UTUC with VH, Follow-up controls should include cross sectional imaging and cystoscopy.

Real-world performance of Uromonitor® in urothelial bladder cancer detection: a multicentric trial

OBJECTIVES

To compare Uromonitor® (U-Monitor Lda, Porto, Portugal), a multitarget DNA assay that detects mutated proto-oncogenes (telomerase reverse transcriptase [TERT], fibroblast growth factor receptor 3 [FGFR-3], Kirsten rat sarcoma viral oncogene homologue [KRAS]), with urine cytology in the urine-based diagnosis of urothelial carcinoma of the bladder (UCB) within a multicentre real-world setting.

PATIENTS AND METHODS

This multicentre, prospective, double-blind study was conducted across four German urological centres from 2019 to 2024. We evaluated the diagnostic performance of Uromonitor compared to urine cytology in a cohort of patients with UCB and in healthy controls within a real-world setting. Sensitivity, specificity, positive-predictive value (PPV), negative-predictive value (NPV), and accuracy of the tests were measured, in addition to multivariate analyses to assess the ability of individual proto-oncogene mutations in detecting UCB. The biometric sample size was designed to achieve a 10% difference in sensitivity.

RESULTS

Patients with UCB comprised 63.7% (339/532) of the study group. Uromonitor showed a sensitivity, specificity, PPV, NPV, accuracy, and an area-under-the-curve of 49.3%, 93.3%, 92.8%, 51.1%, 65.2%, and 0.713%, respectively. These metrics did not demonstrate statistical superiority over urine cytology in terms of sensitivity (44.6%; P = 0.316). Moreover, the comparison of additional test parameters, as well as the comparison within various sensitivity analyses, yielded no significant disparity between the two urinary tests. Multivariate logistic regression underscored the significant predictive value of a positive Uromonitor for detecting UCB (odds ratio [OR] 9.03; P < 0.001). Furthermore, mutations in TERT and FGFR-3 were independently associated with high odds of UCB detection (OR 13.30 and 7.04, respectively), while KRAS mutations did not exhibit predictive capability.

CONCLUSION

Despite its innovative approach, Uromonitor fell short of confirming the superior results anticipated from previous studies in this real-world setting. The search for an optimal urine-based biomarker for detecting and monitoring UCB remains ongoing. Results from this study highlight the complexity of developing non-invasive diagnostic tools and emphasise the importance of continued research efforts to refine these technologies.

[What contribution can make artificial intelligence to urinary cytology?]

Urinary cytology using the Paris system is still the method of choice for screening high-grade urothelial carcinomas. However, the use of the objective criteria described in this terminology shows a lack of inter- and intra-observer reproducibility. Moreover, if its sensitivity is excellent on instrumented urine, it remains insufficient on voided urine samples. Urinary cytology appears to be an excellent model for the application of artificial intelligence to improve performance, since the objective criteria of the Paris system are defined at cellular level, and the resulting diagnostic approach is presented in a highly "algorithmic" way. Nevertheless, there is no commercially available morphological diagnostic aid, and very few predictive devices are still undergoing clinical validation. The analysis of different systems using artificial intelligence in urinary cytology rises clear prospects for mutual contributions.

Optimal Volume Assessment for Serous Fluid Cytology

OBJECTIVE

This study aimed to investigate the optimal volume of serous fluid needed for accurate diagnosis using The International System for Reporting Serous Fluid Cytopathology (TIS), as well as to provide information on the distribution of serous effusion cases in the TIS categories (ND: non-diagnostic, NFM: negative for malignancy, AUS: atypia of undetermined significance, SFM: suspicious for malignancy, MAL: malignant) and relevant epidemiological data.

METHODS

A retrospective analysis of 2340 serous effusion cases (pleural, peritoneal, and pericardial) from two hospitals between 2018 and 2020 was conducted. TIS categories were assigned to each case, and for 1181 cases, these were correlated with the volume of the analyzed fluid.

RESULTS

Our study found statistically significant differences in volume distributions between certain TIS categories. Statistically lower volumes were observed in NFM compared to MAL, in UNCERTAIN (ND, AUS, SFM) compared to both MAL and NFM, and in NOT MAL (ND, NFM, AUS, SFM) compared to MAL. However, these differences were not substantial enough to hold any clinical relevance.

CONCLUSIONS

This study suggests that while fluid volume may slightly influence the TIS category, it does not impact the diagnostic accuracy of serous effusion cytology. Therefore, the ideal serous effusion specimen volume can be defined solely by practical parameters.

A Fully Automated Artificial Intelligence System to Assist Pathologists' Diagnosis to Predict Histologically High-grade Urothelial Carcinoma from Digitized Urine Cytology Slides Using Deep Learning

BACKGROUND

Urine cytology, although a useful screening method for urothelial carcinoma, lacks sensitivity. As an emerging technology, artificial intelligence (AI) improved image analysis accuracy significantly.

OBJECTIVE

To develop a fully automated AI system to assist pathologists in the histological prediction of high-grade urothelial carcinoma (HGUC) from digitized urine cytology slides.

DESIGN, SETTING, AND PARTICIPANTS

We digitized 535 consecutive urine cytology slides for AI use. Among these slides, 181 were used for AI development, 39 were used as AI test data to identify HGUC by cell-level classification, and 315 were used as AI test data for slide-level classification.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Out of the 315 slides, 171 were collected immediately prior to bladder biopsy or transurethral resection of bladder tumor, and then outcomes were compared with the histological presence of HGUC in the surgical specimen. The primary aim was to compare AI prediction of the histological presence of HGUC with the pathologist's histological diagnosis of HGUC. Secondary aims were to compare the time required for AI evaluation and concordance between the AI's classification and pathologist's cytology diagnosis.

RESULTS AND LIMITATIONS

The AI capability for predicting the histological presence of HGUC was 0.78 for the area under the curve. Comparing the AI predictive performance with pathologists' diagnosis, the AI sensitivity of 63% for histological HGUC prediction was superior to a pathologists' cytology sensitivity of 46% (p = 0.0037). On the contrary, there was no significant difference between the AI specificity of 83% and pathologists' specificity of 89% (p = 0.13), and AI accuracy of 74% and pathologists' accuracy of 68% (p = 0.08). The time required for AI evaluation was 139 s. With respect to the concordance between the AI prediction and pathologist's cytology diagnosis, the accuracy was 86%. Agreements with positive and negative findings were 92% and 84%, respectively.

CONCLUSIONS

We developed a fully automated AI system to assist pathologists' histological diagnosis of HGUC using digitized slides. This AI system showed significantly higher sensitivity than a board-certified cytopathologist and may assist pathologists in making urine cytology diagnoses, reducing their workload.

PATIENT SUMMARY

In this study, we present a deep learning-based artificial intelligence (AI) system that classifies urine cytology slides according to the Paris system. An automated AI system was developed and validated with 535 consecutive urine cytology slides. The AI predicted histological high-grade urothelial carcinoma from digitized urine cytology slides with superior sensitivity than pathologists, while maintaining comparable specificity and accuracy.

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.

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.

The usefulness of nuclear area in the diagnosis of high-grade urothelial carcinoma cells in voided urine cytology

OBJECTIVE

The Paris System for Reporting Urinary Cytology considered the nuclear-to-cytoplasmic (N:C) ratio as the most important cytomorphological feature for detecting high-grade urothelial carcinoma (HGUC) cells. Few quantitative studies have been conducted on other features although quantitative studies on the N:C ratio have been reported. Therefore, this study quantitatively analysed important cytomorphological features in distinguishing benign reactive cells from HGUC cells.

METHODS

We analysed 2866 cells from the urine of 52 patients. A digital image analyser was used to quantitatively measure the nuclear area, cell area, N:C ratio, and nuclear roundness for HGUC cells and benign reactive cells. Additionally, the diagnostic value of quantitative cytomorphological criteria in HGUC cells was evaluated by the receiver operating characteristic curve.

RESULTS

The area under the curve for the prediction of HGUC cells for all cells and the top five cells was in the following order: nuclear area (0.920 and 0.992, respectively), N:C ratio (0.849 and 0.977), cell area (0.781 and 0.920), and nuclear roundness (0.624 and 0.605). The best cutoff value of the N:C ratio to differentiate HGUC cells from benign reactive cells was 0.438, and using the N:C ratio of 0.702, the positive predictive value obtained was 100%.

CONCLUSIONS

Our study indicated that nuclear area is a more important cytomorphological criterion than the N:C ratio for HGUC cell detection. Moreover, extracted data of the top five cells were more valuable than the data of all cells, which can be helpful in the routine practice and future criteria definition in urine cytology.

Leveraging thoughtful quality metric selection for individual and system improvements: the atypical category and use of dashboards

Quality management is integral to the practice of cytopathology, especially given the heavily manual workflows and expanding ancillary testing requirements inherent to the cytopathology laboratory. Monitoring quality data like turnaround time, specimen unsatisfactory rates, and diagnostic category utilization rates allows for better understanding of performance with opportunities for targeted improvement if there are variations from that which is expected. However, there are costs to quality monitoring including the time and resources needed, and, in already taxed systems, quality management risks being viewed as just another box to check. While there are mandated quality metrics that must be collected by cytology laboratories, thoughtful selection of key performance indicators can be of tremendous benefit in helping to better understand complex laboratory processes and directing improvement endeavors where needed. The following short communication is a discussion on quality management in the cytopathology laboratory from 3 Cytopathology Quality Management Directors. The discussion focuses on monitoring the atypical reporting category with an emphasis on how trending and visualizing quality metrics can provide laboratories with key data.

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.

Patient-facing communication for cytopathologists: A framework for disclosing diagnostic error

Medical errors are a major source of harm to patients. Regulatory bodies mandate and patient safety experts advocate the disclosure of medical errors to patients to promote transparency and to create accountability for improving health care processes. Although pathologists regularly report errors-either to pathology or clinical colleagues or via internal safety reporting systems-few pathologists directly disclose those errors to patients. Yet many pathologists are interested in participating in the direct disclosure of medical errors to patients and may even be mandated to do so. When surveyed on why they do not directly disclose errors to patients, pathologists commonly cite a lack of confidence and a lack of training. Another barrier cited is the lack of a preexisting relationship between the pathologist and the patient. With respect to this last barrier, cytopathologists have a distinct advantage over surgical or clinical pathologists, as many cytopathologists regularly interact with and develop a rapport with patients when they are performing fine-needle aspiration (FNA) procedures. To improve the safety culture in pathology, direct error disclosure practices must be developed, supported, and strengthened. It is critical for cytopathologists to be comfortable with disclosing errors to patients. Being comfortable with disclosing an error, however, requires training, practice, and advance reflection. Using a practical, case-based format centered around FNA examples, this article addresses how to disclose a medical error to a patient. It provides a framework, heuristic principles, and structured conversation systems and talking points to guide the inexperienced pathologist to find his or her voice in a challenging disclosure conversation.

What's new in WHO fifth edition - urinary tract

The fifth edition of the WHO Blue Book on urological tumours, specifically in the bladder chapter, represents a refinement and update in the classification of bladder tumours building on the aggregate major changes made in previous editions. Progress in the molecular underpinnings of urothelial tumours, particularly with promising stratifiers for more precision-based treatment approaches, have been made. Special attention has been paid to burning questions in bladder pathology, such as grading, heterogeneous lesions, inverted tumours and substaging. The concept of neuroendocrine tumours will be explained precisely.

Clinical evaluation of urine laminin-γ2 monomer as a potent biomarker for non-muscle invasive bladder cancer

BACKGROUND

To evaluate whether urine laminin-γ2 monomer (Ln-γ2m) offers a useful biomarker for patients with non-muscle-invasive bladder cancer (NMIBC).

METHODS

Participants comprised 297 patients, including 111 patients with NMIBC, 136 patients with benign genitourinary disease (BD) and 50 healthy donors (HD). Urine Ln-γ2m was prospectively measured and accuracy was analyzed. Receiver operating characteristic (ROC) curves were determined and area under the ROC curve (AUC) was calculated for urine Ln-γ2m, and compared to those of traditional urine tumor markers such as nuclear matrix protein 22 (NMP22), bladder tumor antigen (BTA) and cytology. The net benefits of combining urine markers were analyzed by decision curve analysis.

RESULTS

Mean urine Ln-γ2m was significantly higher in NMIBC than in BD or HD. The AUC for urine Ln-γ2m was significantly higher than those for urine NMP22, BTA or cytology when comparing NMIBC with HD. In patients with low-grade NMIBC, the AUC for urine Ln-γ2m was higher than the AUCs for NMP22, BTA or cytology. A net benefit of combined examination using urine Ln-γ2m/uCRN with NMP22 was demonstrated.

CONCLUSION

These results suggest urine Ln-γ2m as a potentially useful biomarker for NMIBC, particularly in cases of low-grade cancer.

Bladder cancer detection in patients with neurogenic bladder: are cystoscopy and cytology effective, and are biomarkers pertinent as future diagnostic tools? A scoping review

PURPOSE

To summarize the current state of knowledge on bladder cancer diagnosis and screening in neurogenic bladder patients, and to explore the potential contribution of biomarkers in this context.

METHODS

A scoping review was performed to retrieve cystoscopy and urinary cytology performance for bladder cancer detection in neurogenic bladder patients. We also retrieved information of certified urinary biomarkers in bladder cancer detection and their potential application for this specific population.

RESULTS

A total of 1092 articles were identified; 19 of them were included in the scoping review regarding cytology and cystoscopy performance in patients with neurogenic bladder and 33 were included as related to biomarkers in bladder cancer. No significant study stood out to recommend bladder cancer screening in this specific population using cytology and cystoscopy because of the scarcity of results, low level-of-evidence studies, and lack of studies specifically designed to assess the test performance in this population. Two biomarkers were retained as potential future diagnostic tools: FISH analysis to detect chromosomal changes, and PCR for TERT and FGFR3 promoter mutation detection, associated or not with KRAS mutation detection.

CONCLUSION

There is no sufficient quality data to support cystoscopy and urinary cytology as effective tools for the diagnostic and surveillance of bladder cancer in neurogenic bladder patients. FISH analysis to detect chromosomal changes, and PCR for TERT and FGFR3 promoter mutation detection, associated or not with KRAS mutation detection, stand out as candidates of interest for bladder cancer detection in this specific population and should be prospectively tested.

Novel Non-Invasive Diagnosis of Bladder Cancer in Urine Based on Multifunctional Nanoparticles

Objectives: Tumor cells were reported to have perpetual negative surface charges due to elevated glycolysis, and multifunctional nanoprobes (Fe₃O₄@SiO_2, mNPs) could attach onto tumor cells via opposite surface charges. We thus evaluated whether mixing mNPs with urine could improve the sensitivity of urine cytology test (UCT).

Methods: We developed a novel UCT method by mixing urine with mNPs (Nano-cytology) to harvest more tumor cells during UCT procedures. The same voided urine sample was divided equally for the Nano-cytology and UCT assay, and evaluated by cytopathologists in a blinded way. The accuracy of UCT, Nano-cytology, and the combination of the two approaches (Nano-UCT) for detecting bladder cancer were determined.

Results: Urine samples were prospectively collected from 102 bladder cancer patients and 49 non-cancer participants from June 2020 to February 2021 in Changhai Hospital. Overall sensitivity of the Nano-cytology assay was significantly higher than that of the UCT assay (82.4 vs. 59.8%, p < .01). Sensitivity for low- and high-grade tumors was 79.1% and 39.5% (p < .01) and 84.7% and 74.6% (p = .25) for Nano-cytology and UCT, respectively. Specificity of Nano-cytology was slightly lower than that of UCT (89.8% vs. 100%, p = .022), which is mainly caused by severe urinary tract infection. In addition, Nano-UCT showed increased sensitivity with 90.2% for overall patients, and 83.7% and 94.9% for low- and high-grade tumor, respectively.

Conclusion: The Nano-cytology assay had a significantly improved sensitivity compared with UCT for detecting bladder cancer patients. It represents a promising tool for diagnosis of bladder cancer in clinical practice.

Application of the International System for Reporting Serous Fluid Cytopathology with Cytohistological Correlation and Risk of Malignancy Assessment

The International System for Reporting Serous Fluid Cytopathology (TIS) classifies serous effusions into five categories: non-diagnostic (ND), negative for malignancy (NFM), atypia of unknown significance (AUS), suspicious for malignancy (SFM) and malignant (MAL). The main objectives of this classification comprise the establishment of a universal code of communication between cytopathologists and clinicians and histopathologists, as well as between different laboratories worldwide, paving the way for the setting of clinical management guidelines based on the risk of malignancy assessment for each diagnostic category. We retrieved the total number of pleural and peritoneal effusion cases of our department for the three-year time period between 2018 and 2020, yielding a total of 528 and 500 cases, respectively. We then proceeded to reclassify each specimen according to TIS guidelines and calculate the risk of malignancy (ROM) for each category by searching each patients’ histology records, medical history and clinical follow-up. For pleural effusions, 3 (0.57%) cases were classified as ND, 430 (81.44%) cases as NFM, 15 (2.84%) as AUS, 15 (2.84%) as SFM and 65 (12.31%) as MAL. ROM amounted to 0%, 5.3%, 33.33%, 93.33% and 100% for each category, respectively. As far as peritoneal effusions are concerned, 6 (1.2%) were categorized as ND with ROM estimated at 16.66%, 347 (69.4%) as NFM (ROM = 9%), 13 (2.6%) as AUS (ROM = 38.46%), 12 (2.4%) as SFM (ROM = 83.33%) and 122 (24.4%) as MAL (ROM = 100%). Our results underline the utility of the current classification, both as a means of communication between doctors of different specialties and as general guidelines for the further clinical management of patients.

A deep learning system to diagnose the malignant potential of urothelial carcinoma cells in cytology specimens

BACKGROUND

Although deep learning algorithms for clinical cytology have recently been developed, their application to practical assistance systems has not been achieved. In addition, whether deep learning systems (DLSs) can perform diagnoses that cannot be performed by pathologists has not been fully evaluated.

METHODS

The authors initially obtained low-power field cytology images from archived Papanicolaou-stained urinary cytology glass slides from 232 patients. To aid in the development of a diagnosis support system that could identify suspicious atypical cells, the images were divided into high-power field panel image sets for training and testing of the 16-layer Visual Geometry Group convolutional neural network. The DLS was trained using linked information pertaining to whether urothelial carcinoma (UC) in the corresponding histology specimen was invasive or noninvasive, or high-grade or low-grade, followed by an evaluation of whether the DLS could diagnose these characteristics.

RESULTS

The DLS achieved excellent performance (eg, an area under the curve [AUC] of 0.9890; F1 score, 0.9002) when trained on high-power field images of malignant and benign cases. The DLS could diagnose whether the lesions were invasive UC (AUC, 0.8628; F1 score, 0.8239) or high-grade UC (AUC, 0.8661; F1 score, 0.8218). Gradient-weighted class activation mapping of these images indicated that the diagnoses were based on the color of tumor cell nuclei.

CONCLUSIONS

The DLS could accurately screen UC cells and determine the malignant potential of tumors more accurately than classical cytology. The use of a DLS during cytopathology screening could help urologists plan therapeutic strategies, which, in turn, may be beneficial for patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic value of a comprehensive, urothelial carcinoma-specific next-generation sequencing panel in urine cytology and bladder tumor specimens

BACKGROUND

Urine cytology can reliably diagnose high-grade urothelial carcinoma (HGUC) but not low-grade urothelial carcinoma (LGUC), and a more sensitive test is needed. Previously, a pilot study highlighted the possible diagnostic utility of next-generation sequencing (NGS) in identifying both LGUC and HGUC in urine cytology specimens.

METHODS

Twenty-eight urine ThinPrep cytology specimens and preceding or subsequent bladder tumor biopsy/resection specimens obtained within 3 months were included in the study (LGUC, n = 15; HGUC, n = 13). A customized, bladder-specific NGS panel was performed; it covered 69 frequently mutated or altered genes in urothelial carcinoma (UC) that were reported by The Cancer Genome Atlas and the Catalogue of Somatic Mutations in Cancer.

RESULTS

The sequencing results were compared between the urine cytology specimens and the corresponding bladder tumor biopsies/resections. TP53 was the most frequently identified mutation in HGUC cases (11 of 13 [85%]). PIK3CA and KDM6A were the most frequently identified mutations in LGUC: they occurred in 7 of 15 cases (47%) and in 6 of 15 cases (40%), respectively. Additional frequent mutations identified in the panel included ARID1A (n = 5), EP300 (n = 4), LRP1B (n = 3), ERBB2 (n = 2), STAG2 (n = 2), FGFR3 (n = 3), MLL (n = 2), MLL3 (n = 2), CREBBP1 (n = 1), RB1 (n = 1), and FAT4 (n = 1). Overall, the concordance between the cytology and surgical specimens was 75%. The sensitivity and specificity for identifying mutations in urine cytology specimens were 84% and 100%, respectively.

CONCLUSIONS

A bladder-specific NGS panel increases the sensitivity and specificity of urine cytology's diagnostic utility in both low- and high-grade tumors and may serve as a noninvasive surveillance method in the follow-up of patients with UC harboring known mutations.

Evaluating the Utility of Combined Bladder Cancer Biomarkers, the Molecular Prognostication of Tumor Subtypes, or What Else Is Needed to Illuminate Our Vision?

In the last few years, we published two special issues devoted to highlighting important scientific results in the field of bladder cancer research and clinical implications [...].

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.

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

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.

Comparison of Outcomes Between Radical Radiotherapy and Radical Cystectomy in Muscle Invasive Bladder Cancer in a Cancer Specialized Unit of a Developing Country

Introduction Radical cystectomy (RC) is the current standard of care for treating muscle-invasive bladder cancer (MIBC), however bladder preservation by offering radical radiotherapy (RT) is gaining interest for improving the quality of life while maintaining a reasonable oncological outcome. In this study, we have compared outcomes of the two treatment options. Materials and methods This is a 10-year retrospective cohort study that included all patients who were treated for histologically proven muscle-invasive bladder cancer in the department of uro-oncology at Shaukat Khanum Memorial Cancer Hospital and Research Centre from January 2005 to January 2015. Data was analysed using Statistical Product and Service Solutions (SPSS), version 21 (IBM Corp., Armonk, NY). The primary end point of our study was to calculate the three- and five-year disease-free survival (DFS) and overall survival (OS). Results A total of 230 patients were included in the study with male gender predominating (88%). The mean and standard deviation for age was 58.32+11.128. Radical cystectomy was performed in 119 patients while 111 received RT. Clinically, 34% had stage 2 disease, while 66 % had stage 3 cancer. The median follow-up duration was 41 months (range: 2-155). During follow-up 57.4% of patients showed no recurrence. Local recurrence was found in 9.6% patients and distant metastasis in 32.2%. The three-year DFS of RC was 63% and that of RT was 57% while the five-year DFS for RC and RT were 60% and 49%, respectively (p=0.196). The three-year OS of RC was 64% and that for RT was 58%. On further analysis the five-year OS of RC was 53% and that for RT was 50% (p=0.98). Upon stage-based comparisons, we found no statistically significant difference between the three- and five-year DFS and OS of stage 2 and stage 3 when treated with either modality. Conclusion Most studies favor RC and consider it as the gold standard treatment for muscle-invasive bladder tumor treatment. The current study reveals that bladder preservation approach by chemo radiotherapy is a viable treatment option, having comparable oncological outcomes with patients receiving radical cystectomy, and can be offered to patients having muscle-invasive urothelial bladder cancer.

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.

Small core needle biopsies in cytology practice: a survey of members of the American Society of Cytopathology

INTRODUCTION

The introduction of a new generation of core needle biopsies (CNBs) for endoscopic procedures has prompted reconsideration of the role of cytopathologists in the handling of small biopsies. The American Society of Cytopathology (ASC) has therefore conducted a survey with the intention of elucidating current practices regarding the handling of small CNBs.

MATERIALS AND METHODS

The membership of the ASC was invited by email to participate in an online survey over a 2-month period. The survey consisted of 20 multiple choice questions with 2-8 possible responses per question.

RESULTS

Of 2651 members contacted by e-mail, 282 (10.6%) responded to the survey questions, including 196 pathologists (69.5%) and 86 cytotechnologists (30.5%). Of these, 265 respondents were from the US/Canada (94.0%), with 156 from academic institutions (58.9%) and 109 from non-academic practices (41.1%); 17 were from other countries (6.0%). In 18.8% of all practices, cytopathologists sign out >90% of small CNBs from endoscopic and radiologically guided procedures; in 36.5% of practices >90% are signed out by surgical pathologists; the remainder have such cases divided more evenly between cytopathologists and surgical pathologists. Responses show that 78.0% of all respondents are interested in signing out more small biopsies in the future, and 80.5% desire increased small biopsy-related resources from the ASC.

CONCLUSIONS

The survey responses indicate that practices currently vary widely across institutions. Most indicated an interest in greater incorporation of small biopsies into the practice of cytopathology.

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.

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.