Nuclear hypochromasia: Shedding light on the "lightness" of high-grade urothelial carcinoma.

BACKGROUND: The Paris system (TPS) has provided a standardized classification for reporting urinary cytology, specifically high-grade urothelial carcinoma (HGUC). While hyperchromasia is well described in HGUC, there exists little data on nuclear hypochromasia in HGUC. Our focus was to investigate the incidence of hypochromasia in HGUC and if it should become a criterion for HGUC. DESIGN: All cases of HGUC at our institution for a 3-year interval (2017-2019) using TPS were reviewed. Each case had a single ThinPrep slide and concurrent biopsy or resection specimen to confirm the diagnosis within 30 days. The presence of hypochromasia was evaluated, and cases with hypochromasia were stratified based on the tumor cell percentage. Cases with hypochromasia in 5% or greater of the tumor cells were considered "positively identified" for hypochromasia. RESULTS: We reviewed 117 cases of HGUC and identified nuclear hypochromasia in 12 cases (10.2%) within 5% or greater of the tumor cells. These 12 cases were further assessed based on if tumor cells showed hypochromasia in 5%-49% of the sample, or greater than 50% of the sample. Hypochromasia in 5%-49% of tumor cells was present in 8/117 cases (6.8%); whereas in 50% or greater samples 4/117 cases (3.4%) showed hypochromasia. No cases were identified where hypochromasia was noted in less than 5% of the tumor cells. CONCLUSION: TPS and use of hyperchromasia as a feature of HGUC is affirmed. However, hypochromasia, while not diagnostic in isolation, is present in a sub-set of patients with HGUC (10.2%) and should be considered as a variance noted in the nuclei of HGUC.

Atypical cells parameter in Sysmex UN automated urine analyzer: feedback from the field.

BACKGROUND: "Atypical cells" parameter in automated urinalysis has recently been introduced. An instrument capable of measuring quantitative and qualitative features of nuclear and cytoplasmic properties of a cell has the potential to detect cellular atypia. Instruments using flow cytometry have been detecting atypical cells in blood for a long time; yet instruments using the same methodology very lately developed this parameter in urinalysis. MATERIALS AND METHODS: Samples with an atypical cells value higher than 1 atypical cell/µL were included in the study. Besides automated urinalysis, every sample was reflexed to modular unit for digital imaging. The remainder of each sample was stained with Sternheimer dye and examined manually under a light microscope. RESULTS: 50 samples with higher than1 atypical cell/µL result were included in the study. Patients were composed of 43 females (86 %) and 7 males (14 %). The mean age was 47.12 ± 19.45 years. The median atypical cells value was 1.8/µL (95 % range 1.5-2.4/µL). Manual microscopic evaluation of the 50 samples showed atypical cells in 1 sample. The patient had papillary lesions on cystoscopy and pathology report informed a high grade urothelial carcinoma. Other 49 samples were negative for atypical cells in manual microscopy. They were crowded samples with leucocytes and squamous epithelial cells. CONCLUSIONS: The positive case provided evidence for Sysmex UN's capability to detect atypical cells in urine. The negative cases presented clues that probable vulvovaginal contamination and crowded specimens could be deceptive for Sysmex UN in this particular parameter.

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

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

Targeted education as a method for reinforcing Paris System criteria and reducing urine cytology atypia rates.

INTRODUCTION: The Paris System for Urine Cytology (TPS) provides well-defined diagnostic criteria for the category of atypical urothelial cells (AUC). The current study compares the rate of AUC diagnoses at a large academic medical center before and after an educational intervention (EI) by a urine cytology expert. MATERIALS AND METHODS: An expert in TPS delivered an educational intervention consisting of an interactive microscope session and a didactic session that focused on the AUC diagnostic category. The number of urine cytology cases, the AUC rate, and the false-negative percentage were calculated before and after the EI, using the electronic medical records and cytologic-histologic correlation records. RESULTS: A total of 4026 urine cytology cases were signed out in the 25 months prior to the educational intervention and 1585 cases were signed out in the 10 months after the intervention. EI had a significant impact on diagnostic categorization, including a reduction in AUC (19.6% versus 12.5%) and suspicious for high-grade urothelial carcinoma (3.9% versus 3.1%) diagnoses. The cytotechnologists also placed fewer cases into the AUC category during primary screening (27.6% versus 23.0%). Although a higher percentage of cases was reported as negative for high-grade urothelial carcinoma, the false-negative rate did not significantly change after the intervention (1.8% versus 2.0% of negative cases, P = 0.65). CONCLUSIONS: Focused educational sessions for pathologists and cytotechnologists on the diagnostic criteria for AUC as defined by TPS can significantly reduce the rate of atypical diagnoses without a significant increase in the rate of false negatives.

Evidence-based diagnostic accuracy measurement in urine cytology using likelihood ratios.

INTRODUCTION: Recent cytology classification systems have become more evidence-based and advocate for the use of risk of malignancy (ROM) as a measure of test performance. From the statistical viewpoint, ROM represents the post-test probability of malignancy, which changes with the test result and also with the prevalence of malignancies (or pre-test probability) in each individual practice setting and individual patient presentation. Evidence-based medicine offers likelihood ratios (LRs) as a measure of diagnostic accuracy for multilevel diagnostic tests, superior to sensitivity and specificity as data binarization and information loss are avoided. LRs are used in clinical medicine and could be successfully applied to the practice of cytopathology. Our aim was to establish LRs to compare diagnostic accuracy of The Paris System for Reporting Urinary Cytology (TPS) and of a historic urine cytology reporting system. MATERIALS AND METHODS: We analyzed sequential voided urine cytology cases with histologic outcomes: 188 pre-TPS and 167 post-TPS. LRs were calculated as LR = True positive % (per category)/False positive % (per category) [95% confidence interval] and interpreted LRs = 1 nondiagnostic, LR >1 favor, LR >10 strongly favor, LRs <1 favor exclusion, and LR <0.1 strongly favor exclusion of a target condition, respectively. CATmaker open source software and Fagan nomograms were used for calculation and visualization of the corresponding post-test probability (ROM) of high-grade urothelial carcinoma (HGUC) in various scenarios. RESULTS: Both reporting systems show near-similar performance in terms of LRs, with moderate discriminatory power of negative, suspicious, and positive for HGUC test results. The atypical urothelial cell (AUC) category establishes as indiscriminate LR = 1 in the TPS, whereas in pre-TPS it favored a benign condition. We further demonstrate the utility of LRs to determine individual post-test probability (ROM) in a variety of clinical scenarios in a personalized fashion. CONCLUSIONS: The LRs allow for a quantitative performance measure in case of urine cytology across different scenarios adding numeric information on diagnostic test accuracy and post-test probability of HGUC. The diagnostic accuracy of pre-TPS and post-TPS remained similar for all but the AUC category. With the TPS, the AUC category has become genuinely diagnostically and statistically indeterminate and requires further patient investigations.

High-grade urothelial carcinoma in urine cytology: different spaces - different faces, highlighting morphologic variance.

INTRODUCTION: The Paris System for Reporting Urinary Cytology (TPS) was first published in 2016 to standardize reporting and placed a specific emphasis on high-grade urothelial carcinoma (HGUC). The urinary tract is anatomically divided into the upper tract (UT) and the lower tract (LT). A major morphologic criterion in TPS for HGUC defines the nuclear-to-cytoplasmic (N/C) ratio as ≥ 0.7. In this study, we evaluated N/C ratios of HGUC arising from UT and LT urine specimens, to ascertain differences due to location. MATERIALS AND METHODS: Digital annotations of whole slide scanned images were performed and enumerated. RESULTS: The cohort consisted of 59 ThinPrep specimens from 52 patients. The majority of the tumors were located in LT (39 of 59, 66.1%). A total of 590 cells were analyzed (10 cells per case). In UT, the average N/C was 0.58 and LT the average was 0.54 (P < 0.001). The average nuclear area for UT was 126.3 and for LT was 158.2 µm2 (P = 0.01). The average cytoplasmic area for UT was 219.1 µm2 and for LT was 296.2 µm2 (P < 0.001). The average cellular circumference for UT was 59.4 µm and for LT was 66.1 µm (P < 0.001). CONCLUSIONS: We found that UT HGUCs have higher N/C ratios, smaller cell circumference, smaller nuclei, and less cytoplasm compared with LT. When UT was divided into renal pelvis and ureter, no statistical difference was identified.

An institutional experience evaluating hTERT immunostaining in 100 consecutive ThinPrep urine specimens.

INTRODUCTION: Studies have shown that expression of human telomerase reverse transcriptase (hTERT) in mature urothelial cells indicates an increased risk of urothelial carcinoma. We evaluated the utility of immunocytochemistry with a commercially available anti-hTERT antibody (SCD-A7) in 100 consecutive urine cytology specimens using ThinPrep processing. MATERIALS AND METHODS: ThinPrep slides prepared from 100 consecutive urine specimens were stained using anti-hTERT antibody (SCD-A7) after staining optimization had been successfully completed. Patient demographics, cytology diagnoses, histologic follow-up data, and anti-hTERT staining results were recorded. RESULTS: The cytology diagnoses included 7 cases of high-grade urothelial carcinoma (HGUC), 2 cases suspicious for HGUC (SHGUC), 24 cases of atypical urothelial cells (AUCs), and 67 cases negative for HGUC (NHGUC). Of 92 samples, 68 (74%) were positive and 24 (26%) were negative for anti-hTERT staining. Although 31 of 32 specimens (97%) with a diagnosis of AUCs and greater showed positive staining, 37 of 60 NHGUC cases (62%) were also positive for anti-hTERT. Although the HGUC and suspicious for HGUC cases were more likely to show strong staining (6 of 9; 67%), 7 AUC (32%) and 8 NHGUC (22%) cases also demonstrated strong staining. Eight samples (8%) were unsatisfactory for interpretation. Anti-hTERT staining of nonurothelial cells was seen in 77 of 92 samples (84%). CONCLUSIONS: Interpretation of anti-hTERT immunocytochemical staining of ThinPrep material is challenging owing to obscuring of nonurothelial cell staining and difficulty discerning individual urothelial cell cytomorphology when the cells are stained. The significance of the large number of anti-hTERT-positive but cytology-negative cases in our study is uncertain.

The Paris System "atypical urothelial cells" category: can the current criteria be improved?

INTRODUCTION: The Paris System (TPS) for reporting urine cytology was developed for standardization of diagnosis focusing on the detection of high-grade urothelial carcinoma (HGUC). Probably the most challenging task for TPS is to provide criteria for the atypical urothelial cell (AUC) category. The TPS criteria for AUC include increased nuclear/cytoplasmic (N/C) ratio (>0.5) and 1 of the 3 minor criteria including nuclear hyperchromasia (NH), coarse chromatin (CC) and irregular nuclear membrane (INM). We evaluated TPS-AUC diagnostic value and investigated whether other morphologic parameters can improve its criteria. MATERIALS AND METHODS: Urine samples with diagnoses of AUC collected during a 6-month period were re-reviewed. Data captured included N/C ratio >0.5, NH, CC, INM, and 2 additional criteria including enlarged nuclear size (ENS) and the presence of nucleolus (N). ENS was considered when the nucleus was 2 times larger than the urothelial cell or 3 times larger than lymphocyte. RESULTS: By applying the TPS-AUC criteria, the rate of atypia diagnosis reduced in comparison to Pre-TPS (9% versus 13%, P = 0.02). Among the AUC minor criteria, NH was the best criterion with the highest interobserver agreement (IOA) and correlation with HGUC (k = 0.342, r = 0.61, P < 0.001) and strong PPV (93.6%). ENS had the highest PPV (95.8%) and, after NH, had the highest IOA and correlation with HGUC (k = 0.29, r = 0.52, P < 0.001). CONCLUSION: TPS improves the diagnostic value of urine cytology, particularly in cases with atypia. ENS is a strong criterion for increasing the diagnostic value of AUC and potentially can improve TPS performance as a minor criterion.

A new 7-point method facilitates accurate diagnosis of high-grade urothelial carcinoma in routine urinary cytology practice.

INTRODUCTION: This study was designed to identify the minimal and necessary cell morphologies to be considered for high-precision diagnosis of high-grade urothelial carcinoma (HGUC) in a routine urinary cytology practice. MATERIALS AND METHODS: We included 338 urine cytology specimens from 11 medical facilities in Japan. Six experts evaluated these Papanicolaou-stained specimens using their own diagnostic criteria to categorize them within an initial 4-tiered classification system. Of the 338 cases, 70 HGUC and 32 benign cases (with a complete consensus diagnosis of 6 experts) were included for the analysis. Two of the cytologists evaluated the specimens for 20 specific cellular features. The results were analyzed using a contingency table and by discriminant analysis. RESULTS: Of the original 338 cases, 165 were originally diagnosed as HGUC, but only 70 (42.4%) were scored as malignant by all participating cytologists; of the 101 benign cases, only 32 (31.7%) were classified as such in all examinations. These specimens were re-evaluated by 6 experts using a panel of 20 specific cellular features used to distinguish between HGUC and benign diseases; tests of significance and discriminant analyses identified 7 critical features that were most useful for cytological diagnosis. Statistical analysis revealed that a focus on these 7 features led to a diagnosis of HGUC with a probability of over 95%. CONCLUSIONS: The accuracy of our presently used method to evaluate urinary cytology is not consistently high. This novel classification system, which focuses on 7 critical features, facilitates the high accurate diagnosis of HGUC in routine cytology practice.

Cell blocks in urine cytopathology: do they add value to the diagnosis? A pilot study.

INTRODUCTION: The utility of cell block (CB) preparation is well established in cytopathology. Despite 23.3% of College of American Pathologists-accredited laboratories using CB with liquid-based preparations on urine cytology (UC) cases, there are very few studies on their performance. To determine their usefulness, we conducted a retrospective review of UC cases that received CB. MATERIALS AND METHODS: We identified 27 UC cases with ThinPrep (TP) and CB preparation between 2016 and 2020 at our institution. Clinical history and follow-up data were compiled. A blinded review of TP alone, and TP together with CB, was performed by 2 pathologists and 2 cytotechnologists. Diagnoses were rendered in accordance with The Paris System for Reporting Urine Cytology. RESULTS: Blood and acute inflammation were common background elements in cases that received CB preparation. In total, CB upgraded the diagnosis in 7 of 27 cases (26%). The maximum utility of CB preparation was seen in indeterminate cases where 60% (6 of 10) were upgraded, including 71% (5 of 7) of atypical urothelial cells (AUC) and 30% (1 of 3) of suspicious for high-grade urothelial carcinoma (HGUC). One case (1 of 12, 8%) diagnosed as negative for HGUC on TP was diagnosed as low-grade urothelial neoplasia on CB. CONCLUSIONS: Our results demonstrate that adjunct use of CB preparation aids in a definitive diagnosis on AUC category and may be helpful in cases with cell clusters or tissue fragments, or cases suspicious for HGUC. Further correlation studies are warranted in this area to expand our knowledge about the utility of CBs in urine cytology.

Developing a Machine Learning Algorithm for Identifying Abnormal Urothelial Cells: A Feasibility Study.

INTRODUCTION: Urine cytology plays an important role in diagnosing urothelial carcinoma (UC). However, urine cytology interpretation is subjective and difficult. Morphogo (ALAB, Boston, MA, USA), equipped with automatic acquisition and scanning, optical focusing, and automatic classification with convolutional neural network has been developed for bone marrow aspirate smear analysis of hematopoietic diseases. The goal of this preliminary study was to determine the feasibility of developing a machine learning algorithm on Morphogo for identifying abnormal urothelial cells in urine cytology slides. METHODS: Thirty-seven achieved abnormal urine cytology slides from cases with the diagnosis of atypical urothelial cells and above (suspicions or positive for UC) were obtained from 1 hospital. A pathologist (J.R.) reviewed the slides and manually selected and annotated representative cells to feed into Morphogo with following categories: benign (urothelial cells, squamous cells, degenerated cells, and inflammatory cells), atypical cells, and suspicious cells. Initial validation of the algorithm was performed on a subset of the original 37 cases. Urine samples from additional 12 unknown cases with various histological diagnoses (6 cases of high-grade urothelial carcinoma (HGUC), 1 case of low-grade urothelial carcinoma (LGUC), 1 case of prostate adenocarcinoma, 1 case of renal cell carcinoma, and 4 cases of non-neoplastic conditions) were collected from another hospital for initial blind testing. RESULTS: A total of 1,910 benign and 1,978 abnormal (atypical and suspicious) cells from 37 slides were annotated for developing and training of the algorithm. This algorithm was validated on 27 slides that resulted in identification of at least 1 abnormal cell per slide, with a total of 200 abnormal cells, and an average of 7.4 cells per slide. Of the 12 unknown cases tested, the original cytology was positive for tumor cells in 2 HGUC samples. Morphogo was abnormal (atypical or suspicious) for 6 samples from patients with UC, including one with LGUC and one with prostate adenocarcinoma. CONCLUSION: Morphogo machine learning algorithm is capable of identifying abnormal urothelial cells. Further validation studies with a larger number of urine samples will be needed to determine if it can be used to assist the cytological diagnosis of UC.

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

INTRODUCTION: Urothelial carcinoma (UC) requires lifelong monitoring, commonly through urinary cytology and cystoscopy. Urine cytology has a relatively high sensitivity for detecting high-grade urothelial carcinoma (HGUC); however, its sensitivity for low-grade urothelial neoplasm (LGUN) is significantly lower with wide interobserver variability. The Paris System (TPS) was proposed to create standardized diagnostic categories with defined cytomorphologic criteria. We attempt to evaluate diagnostic efficacy of identifying UC using TPS through cytologic-histologic correlation. MATERIALS AND METHODS: A retrospective search identified 170 cases of urine cytology cases with concurrent biopsies collected during a 2-year time period at University of Rochester Medical Center. Patient age, sex, smoking history, prior malignancy diagnoses, cystoscopy findings, specimen collection method, UroVysion results, and 1-year follow-up of surgical pathology cases were included. RESULTS: Cytologic-histologic correlation was identified in 59% of cases, with 18% true positives and 41% true negatives. Discordant results were identified in 41% of cases; of these, 4% were false positives, 11% false negatives, 12% potential sampling bias, and 14% were low-grade urothelial carcinoma (LGUC). The analysis of this 2-year study finds a positive predictive value of urine cytology for HGUC to be 81%, a negative predictive value of 79%, a sensitivity of 61%, a specificity of 91%, and an accuracy of 79%. CONCLUSIONS: Our results support TPS's ability to improve the reliability and accuracy of interpretations in urine cytology for HGUC. Nevertheless, additional studies are essential to improve the diagnostic accuracy of LGUN, and urine adequacy, in order to improve patient care and early detection, while identifying potential sampling bias.

High-grade urothelial carcinoma with hypochromatic chromatin in urine cytology.

INTRODUCTION: Some high-grade urothelial carcinomas (UCs) in urine cytology have hypochromatic chromatin, but the incidence and criteria for diagnosis are not well described. MATERIALS AND METHODS: Urine cytology cases with biopsy follow up were reviewed. RESULTS: Cytospin preparations from 331 cases with biopsy follow up (230 benign/low-grade UC, 101 malignant) were reviewed. There were no false-positive cases. Cases with malignant cells with hypochromatic chromatin were identified in a total of 17 cases (16.8% of all malignancies). These comprised 2 carcinoma in situ, 11 high-grade papillary UC, 3 invasive UC, and 1 adenocarcinoma. Sixteen of 93 high-grade UCs (17.2%) had cells with hypochromatic chromatin. These cells were the only type of malignant cell in 4 of 101 cases (4.0%). All cases had cells with high nuclear-to-cytoplasmic ratios and markedly indented and irregular nuclear membranes that could be identified on both cytology and subsequent histology. CONCLUSIONS: Malignant urothelial cells in urine cytology with hypochromatic chromatin can be present in 17% of cases and can be diagnosed as "positive for malignancy" based on their high nuclear-to-cytoplasmic ratio, and markedly indented and irregular nuclear membranes.

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.

The Paris System for Reporting Urinary Cytology reduces atypia rates and does not alter the negative predictive value of urine cytology.

INTRODUCTION: The Paris System for Reporting Urinary Cytology (TPS) was developed for standardization purposes and it placed an emphasis on screening for high-grade urothelial carcinoma (HGUC). Since then, it has shown to reduce atypia rates and better correlate with surgical specimens. The aim of this study was to calculate the negative predictive value (NPV) of urinary cytology for detecting HGUC using TPS and compare these data to our recently published pre-TPS cohort. As a screening test, it is imperative that TPS has a high NPV. MATERIAL AND METHODS: A search of our institution's pathology database for the term "negative for HGUC" from January 1, 2016, to December 31, 2017, was conducted. A true negative was defined as a patient with at least 1 subsequent negative urine cytology/surgical biopsy specimen or the patient being clinically negative for 6 months. NPV rates were calculated based on the data obtained. RESULTS: The cohort consisted of 2960 urine cytology specimens from 1894 patients. A total of 99 false negatives were identified, generating a NPV of 96.7% (2861/2960). This NPV is identical to our previously published pre-TPS cohort (years 2012-2013; NPV: 96.7%). The clinical indication most effected NPV, with a history of urothelial carcinoma with a NPV of 93.9% followed by hematuria at 98.9%. The atypia rate in years 2012-2013 was 8.2% and in 2016-2017 it was 5.7% (P < 0.001). CONCLUSIONS: We demonstrate that TPS did not alter the NPV for detecting HGUC compared to our pre-TPS cohort. We believe that TPS is an effective reporting system for screening HGUC in urinary cytology.

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.

Outcome analysis and negative predictive value of the "unsatisfactory/nondiagnostic" category of The Paris System for Reporting Urinary Cytology.

INTRODUCTION: The Paris System (TPS) for Reporting Urinary Cytology (UCyto) was published in 2016, but to date, no study addressing the unsatisfactory (UNSAT) category has been published. We aimed to identify the negative predictive value (NPV) for UNSAT UCyto after the implementation of TPS at our institution. METHOD: For the period from January 1, 2017, to December 31, 2019, we identified all cases with UNSAT diagnosis on UCyto specimens and available cytologic and/or surgical pathology follow-up within 6 months from the UNSAT diagnosis. Cases were deemed true negative (TN) if the follow-up was "negative for high-grade urothelial carcinoma" (NHGUC). Information regarding previous medical history, clinical indications, and specimen type were tabulated and analyzed. RESULTS: From 6348 UCyto specimens, there were 230 (3.6%) UNSAT diagnoses made on 209 patients (112 [53.6%] men and 97 [46.4%] women) with a median age of 64 years. Of these, 116 UCyto specimens from 106 patients, which had cytologic and/or surgical pathology follow-up within 6 months, were further studied. Most UNSAT UCyto specimens were bladder washing/barbotage (BW/BB), and the most common indication for UCyto was cancer surveillance. The main cause of UNSAT UCyto was low cellularity. There were 5 false-negative (FN) results for high-grade urothelial carcinoma (HGUC), which corresponds to an overall NPV of 84.4%. NPV was highest for patients with UCyto for hematuria, and for patients with BW/BB as UCyto specimen type. CONCLUSIONS: Our results show that UNSAT diagnoses have a lower NPV than that typical of NHGUC diagnoses, and should be managed accordingly.