Diagnostic significance of atypical category in the voided urine samples: A retrospective study in a tertiary care center

Reclassification of Urinary Cytology according to the Paris System for Reporting Urinary Cytology Correlation with Histological Diagnosis

INTRODUCTION

The Paris System for Reporting Urinary Cytology (TPS) was designed to provide precise diagnostic criteria when evaluating urine cytology and standardize the terminology used in reporting. In our study, we have aimed to determine the effect of TPS on the diagnostic performance of urine cytology, its impact on establishing appropriate risk stratification, and its effectiveness in the diagnosis and follow-up of the patients.

METHODS

We reevaluated 200 liquid-based urine cytologies with available histological diagnoses reported between 2015 and 2021 according to TPS criteria and compared them with the original cytological diagnoses. Area under the curve, sensitivity, specificity, and diagnostic accuracy of both methods were calculated and statistically analyzed to determine the diagnostic performance of the original reporting and TPS.

RESULTS

The sensitivity, specificity, positive predictive, negative predictive, and diagnostic accuracy rates of TPS were 60%, 99.3%, 97.2%, 97.2%, 85.7%, and 87.2%, respectively. In TPS, the risk of malignancy for negative for high-grade urothelial carcinoma, atypical urothelial cells, suspicious for high-grade urothelial carcinoma, and high-grade urothelial carcinoma (HGUC) is 3.5%, 20.9%, 60.8%, 97.2%, respectively. In the original reporting, the corresponding risks were 13.4%, 15%, 52%, 100%, respectively. A statistically significant difference was observed between diagnostic criteria of original cytology and TPS (p = 0.001). When the original reporting was compared with the TPS, the discriminative power of TPS in the diagnosis of HGUC was significantly higher (p < 0.001).

CONCLUSIONS

The use of TPS provided a more accurate risk stratification of patients. The diagnostic performance of urine cytology was improved, especially for HGUC.

Clinical application of the anti-human telomerase reverse transcriptase (hTERT) antibody (SCD-A7) immunocytochemistry in liquid-based urine cytology: A prospective, single institute study

OBJECTIVES

Urine cytology is the most widely used noninvasive screening tool for urothelial carcinoma diagnosis and surveillance. Although highly specific, urine cytology exhibits suboptimal sensitivity. This study aimed to determine whether hTERT immunocytochemistry (ICC) could be applicable as an ancillary test in routine cytology practice.

METHODS

A total of 561 urinary tract samples were initially screened in this study. All of them were prepared using SurePath liquid-based cytology (LBC), while additional LBC slides were made and subsequently used for hTERT (SCD-A7) ICC.

RESULTS

From the 561 samples screened, 337 were finally analyzed, all having an adequate cellularity and available follow-up histology. The hTERT ICC-positive rate was 95.9% (n = 208/217), 96% (n = 24/25), and 100% (n = 4/4) in cytology samples with high-grade urothelial carcinoma, carcinoma in situ, and low-grade urothelial carcinoma subsequent histology. Among the 64 atypical cytology cases histologically confirmed as urothelial carcinomas, 92.2% (n = 59/64) were immunoreactive to hTERT, whereas the two histologically benign cases were ICC-negative. 87/90 (96.7%) of the cytology cases confirmed to be benign in follow-up were hTERT-negative. The overall sensitivity and specificity of hTERT ICC were 96.3% and 98.8%, respectively (AUROC = 0.963; 95% CI = 0.960-0.967).

CONCLUSIONS

The hTERT ICC test exhibited consistent and intense staining in malignant urothelial cells, suggesting its value as an ancillary test in liquid-based urine cytology.

Uncovering additional predictors of urothelial carcinoma from voided urothelial cell clusters through a deep learning-based image preprocessing technique

BACKGROUND

Urine cytology is commonly used as a screening test for high-grade urothelial carcinoma for patients with risk factors or hematuria and is an essential step in longitudinal monitoring of patients with previous bladder cancer history. However, the semisubjective nature of current reporting systems for urine cytology (e.g., The Paris System) can hamper reproducibility. For instance, the incorporation of urothelial cell clusters into the classification schema is still an item of debate and perplexity among expert cytopathologists because several previous works have disputed their diagnostic relevance.

METHODS

In this work, an automated preprocessing tool for urothelial cell cluster assessment was developed that divides urothelial cell clusters into meaningful components for downstream assessment (ie, population-based studies, workflow automation).

RESULTS

In this work, an automated preprocessing tool for urothelial cell cluster assessment was developed that divides urothelial cell clusters into meaningful components for downstream assessment (ie, population-based studies, workflow automation). Results indicate that cell cluster atypia (i.e., defined by whether the cell cluster harbored multiple atypical cells, thresholded by a minimum number of cells), cell border overlap and smoothness, and total number of clusters are important markers of specimen atypia when considering assessment of urothelial cell clusters.

CONCLUSIONS

Markers established through techniques to separate cell clusters may have wider applicability for the design and implementation of machine learning approaches for urine cytology assessment.

Large-scale longitudinal comparison of urine cytological classification systems reveals potential early adoption of The Paris System criteria

INTRODUCTION

Urine cytology is used to screen for urothelial carcinoma in patients with hematuria or risk factors (eg, smoking, industrial dye exposure) and is an essential clinical triage and longitudinal monitoring tool for patients with known bladder cancer. However, urine cytology is semisubjective and thus susceptible to issues including specimen quality, interobserver variability, and "hedging" towards equivocal ("atypical") diagnoses. These factors limit the predictive value of urine cytology and increase reliance on invasive procedures (cystoscopy). The Paris System for Reporting Urine Cytology (TPS) was formulated to provide more quantitative/reproducible endpoints with well-defined criteria for urothelial atypia. TPS is often compared to other assessment techniques to justify its adoption. TPS results in decreased use of the atypical category and better reproducibility. Previous reports comparing diagnoses pre- and post-TPS have not considered temporal differences between diagnoses made under prior systems and TPS. By aggregating across time, studies may underestimate the magnitude of differences between assessment methods.

MATERIALS AND METHODS

We conducted a large-scale longitudinal reassessment of urine cytology using TPS criteria from specimens collected from 2008 to 2018, prior to the mid-2018 adoption of TPS at an academic medical center.

RESULTS

Findings indicate that differences in atypical assignment were largest at the start of the period and these differences progressively decreased towards insignificance just prior to TPS implementation.

CONCLUSIONS

This finding suggests that cytopathologists had begun to utilize the quantitative TPS criteria prior to official adoption, which may more broadly inform adoption strategies, communication, and understanding for evolving classification systems in cytology.

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

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

[How has the Paris System contributed to urine cytology? Evaluating the contribution of the Paris System to urine cytology. A comparative study of the Paris System and the Papanicolaou method in a tertiary centre]

INTRODUCTION AND OBJECTIVES

The Paris System (PS) has replaced the classical Papanicolaou System (PapS) in reporting urine cytology, due to its improved sensitivity and negative predictive value (NPV) without loss of specificity. Furthermore, it has enabled the risk of malignancy to be established in each cytological category. The aim of this study is to compare the Paris System with previous results and determine the changes in sensitivity, specificity, positive predictive value, NPV and risk of malignancy in our centre, MATERIALS AND METHODS: Evaluation of the diagnostic power of urine cytology by means of a retrospective cohort study, comparing two series of 400 cytological studies, one using the Papanicolaou System and the other the Paris System.

RESULTS

In the detection of high-grade urothelial carcinoma, Paris System has better specificity (93.82% PapS vs 98.64% PS; P=.001) and PPV (39.5% PapS vs 70.6% PS; P=.044) than Papanicolaou System, without changes in sensitivity (53.5% PapS vs 37.5% PS; P=.299) or NPV (96.4% PapS vs 94.8% PS; P=.183). The risk of malignancy for the atypical category increases from low to high levels (1.6% PapS vs 40.0% PS; P=.001); the other categories showed no significant statistical changes.

CONCLUSION

The Paris System improves specificity and positive predictive value and establishes a better indication of risk of malignancy for each category, enabling specific clinical management in each case.

The bladder epicheck test and cytology in the follow-up of patients with non-muscle-invasive high grade bladder carcinoma

BACKGROUND

The management of non-muscle invasive bladder carcinoma (NMIBC) after transurethral resection of a bladder tumor consists of adjuvant intravesical therapy and strict and long surveillance with urine cytology and cystoscopy. The Bladder EpiCheck test (Nucleix Ltd) (BE) is a newly developed urinary markers based on DNA methylation changes in a panel of 15 genomic biomarkers, with a promising performance in term of non-invasive NMIBC detection.

METHODS

In this study we prospectively enrolled 151 consecutive patients with high grade NMIBC, treated with intravesical BCG and mitomycin C therapy and evaluated during the follow-up by voided urine cytology and white-light cystoscopy, according to the European Association of Urology Guidelines. The Bladder EpiCheck test was performed at the same time of urine cytology in voided specimen. In all cases with positive cytology the diagnosis was confirmed by histology and a diagnosis was made according to the 2017 tumor, node, metastasis (TNM) classification and graded using both the 1973 and the 2004 World Health Organization (WHO) classifications.

RESULTS

At three months of follow-up, we reported similar overall specificity rates for BE and urine cytology (85,1% vs 86,3%). In the group of patients with carcinoma in situ (CIS), we found the same specificity for BE and urine cytology (81,4%), while in the groups of patients with papillary high grade NMIBC, the specificity of BE was higher compared to cytology (96,3% vs 90,4%). The sensitivity of BE was always higher compared to cytology during all the follow-up both for papillary NMIBC and CIS.

CONCLUSION

In the early follow-up of NMIBC the EpiCheck test might replace urinary cytology.

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

Background:

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

Aims:

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

Materials and Methods:

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

Results:

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

Conclusions:

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

Methylation study of the Paris system for reporting urinary (TPS) categories

AIMS

Bladder EpiCheck is one of several urinary tests studied to identify bladder tumours and analyses 15 methylation biomarkers determining bladder cancer presence on the basis of methylation profile.

METHODS

374 patients diagnosed with high-grade non-muscle invasive bladder cancer were treated and followed for 1 year with voided urine cytology and white-light cystoscopy and biopsies according to European Association of Urology Guidelines. 268 cases were diagnosed with high-grade papillary carcinoma, while 106 cases were carcinoma in situ. Bladder EpiCheck test was performed together with cytology in all cases.

RESULTS

Comparing cytological categories of negative for high-grade urothelial carcinoma (NHGUC) and atypical urothelial cells (AUCs), we found that an EpiScore <60 correlates with NHGUC (p=0.0003, Fisher's exact test), while comparing AUC and suspicious for high-grade urothelial carcinoma (SHGUC) or SHGUC and high-grade urothelial carcinoma (HGUC) categories, an EpiScore ≥60 correlates with SHGUC and HGUC, respectively (p=0.0031 and p=0.0027, Fisher's exact test). In each TPS category, we found that sensitivity, specificity, Positive Predicitve Value (PPV) and Negative Predictive Value (NPV) of the Bladder EpiCheck test in HGUC category were higher than those observed in SHGUC group (sensitivity=98%, specificity=100%, NPV=85.7%, PPV=100% vs sensitivity=86.6%, specificity=52.3%, NPV=84.6%, PPV=56.5%).

CONCLUSIONS

Analysing methylation study results, we demonstrated that different TPS cytological categories also carry a distinct molecular signature. Moreover, our results confirm that cytological categories SHGUC and HGUC are different entities also from a molecular point of view and should continue to represent distinct groups in TPS.

Reclassification of urinary cytology regarding The Paris System for Reporting Urinary Cytology with cytohistological correlation demonstrates high sensitivity for high-grade urothelial carcinoma

BACKGROUND

Recently, The Paris System for Reporting Urinary Cytology (TPS) has led to major changes in the approach to evaluate urine cytology and pattern of reporting. The aim of this study was to reclassify urine cytology reports with TPS in order to determine the frequency of abnormal results compared with the previous system; also, we performed cytohistological correlation in abnormal cytological results.

METHODS

In this study, the voided urine specimens from the patients referred to Shiraz University of Medical Sciences affiliated laboratories were retrieved and analyzed using the laboratory's electronic records system; slides prepared from the samples were reviewed by single cytopathologist blindly according to the proposed criteria of TPS.

RESULTS

Totally, 1842 urine cytology slides from 828 patients were blindly evaluated by TPS criteria and compared with routine urine cytology classification. Then, available cytohistological correlation was done on 99 abnormal urine cytological results from 58 patients. Among the 26 cytology slides with atypical urothelial cell (AUC) in the previous classification, eight (30.70%) slides were downgraded to negative results, and four (15.30%) were upgraded to higher groups. Therefore, through the reclassification of the slides with TPS, 46% of the AUC changed to other groups. Diagnostic accuracy of the TPS classified urine cytology was 78%, including 87.88% sensitivity, 27.27% specificity, 64.44% positive predictive value, and 60% negative predictive value.

CONCLUSION

The findings of the present study confirmed the importance and utility of TPS regarding the reclassification of AUC to other groups and its high sensitivity for detecting high-grade urothelial carcinoma (HGUC).

Diagnostic Agreement for High-Grade Urothelial Cell Carcinoma in Atypical Urine Cytology: A Nationwide Survey Reveals a Tendency for Overestimation in Specimens with an N/C Ratio Approaching 0.5

In the Paris System (TPS), standardized cytomorphological criteria and diagnostic categories were proposed for reporting urine cytology. To evaluate the diagnostic agreement and interobserver concordance for assessing TPS criteria, the Taiwan Society of Clinical Cytology organized an online survey with 10 atypical urine cytology cases. A total of 137 participants completed the survey. The mean agreement of diagnosis was 51.2%, ranging from 34.3% to 83.2% for each case. For 60% (6/10) of cases, the agreement was <50%. The interobserver concordance of diagnosis and cytological criteria assessment showed poor agreement. The nuclear-to-cytoplasmic (N/C) ratio had the highest kappa value of 0.386, indicating a significantly higher interobserver concordance and reproducibility than the other three TPS criteria. The correct rate of assessing the N/C ratio increased as the N/C ratio increased (correlation coefficient: 0.891, p < 0.01). Three cases with an N/C ratio near 0.5 were overestimated. Poor interobserver concordance of diagnosis and TPS criteria was revealed. Compared with other cytological features, the N/C ratio assessment was quantitative and more reproducible, but a tendency to overestimate cells was noted when the N/C ratio was approximately 0.5. Continuing education programs should emphasize the accurate assessment of N/C ratio to improve the application of TPS.

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

Background:

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

Materials and Methods:

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

Results:

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

Conclusions:

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

Significance of atypical urinary cytology in the evaluation of patients with end-stage renal disease for kidney transplantation - a retrospective study

To determine what percentage of renal transplant candidates have atypical urinary cytology, what proportion have urothelial carcinoma and whether cystoscopy is necessary with atypical cytology. All end-stage renal disease (ESRD) patients (703) presenting for renal transplantation at our institution were retrospectively reviewed. Individuals producing sufficient urine were screened with urine cytology and those with atypical cytology or risk factors for bladder cancer underwent cystoscopy. Four hundred and thirty patients had available urinary cytology and, of these, 151 (35%) had atypical cytology. Of patients with atypical cytology, three were identified to have urothelial carcinoma. However, three additional patients with urothelial carcinoma did not present with atypical cytology. In total, 6 of 703 (0.85%) patients had bladder cancer. All were treated with transurethral resection and eventually underwent renal transplant. One patient has had disease progression post-transplant to distant metastases. This is the largest study to date evaluating the incidence of urothelial carcinoma in ESRD patients presenting for transplant workup. We found the incidence of bladder cancer to be higher than in the general Canadian population, however, most lesions were low grade. We found atypical cytology in transplant candidates to be a poor predictor for these low-grade lesions and do not recommend routine cystoscopy for atypical cytology.

A Review of Urine Ancillary Tests in the Era of the Paris System

Aside from its diagnostic importance, urinary tract endoscopy is an uncomfortable, expensive, and time-consuming procedure. Patients with a history of urothelial carcinoma remain at an increased risk for recurrence and the development of de novo disease; most have had exposure to carcinogenic risk factors for decades prior to their first diagnosis that have bathed the entire urothelial tract. Consequently, monitoring these patients over their lifetime has made urothelial carcinoma one of the most expensive cancers for the US healthcare system. This expense has provided a financial incentive for academic and commercial groups to develop a test with a sufficient negative predictive value to reduce the frequency of surveillance procedures. Slide-based tests require a separate slide prepared from a split urine sample or from an additional urinary tract specimen. This process can place an additional burden on the laboratory due to changes in the workflow, especially if the split specimens need to be stored until a cytologic diagnosis is rendered (i.e., when used as a reflex test). Importantly, slide-based tests allow for the result to be directly correlated with cytomorphologic findings; however, these tests require the cells of interest to be present. Thus, slide-based tests suffer from the same sensitivity issues as urinary tract cytology. In contrast, slide-free tests do not require an additional slide to be prepared, and laboratory testing may be centralized to a core facility or performed on-site. Some tests detect the expression of altered or abnormally expressed subcellular material (proteins, DNA, etc.) in urothelial neoplasms, which are found in tumor cells and/or in the urine specimen when the proteins are either excreted or leaked from degenerating tumor cells. Slide-free tests may also be developed into point-of-care tests, meaning that the result may be available to the urologist but not to the cytopathologist. Since these proteins are often disassociated from the tumor cells that produce them, such tests may have a positive result even if tumor cells are absent in the tested specimen. Here we review critical concepts as well as several ancillary tests that have been developed for urinary tract specimens.

Fluorescence in situ hybridization in 1 mL of selective urine for the detection of upper tract urothelial carcinoma: a feasibility study

Kidney-sparing surgery of upper tract urothelial carcinoma (UTUC) requires a stringent follow-up with frequent ureteroscopies. Triage testing could reduce the number of follow-up ureteroscopies and hence minimize the invasiveness of follow-up. The use of urine-based markers for triage seems appealing but should be feasible with selective urine from outpatient cystoscopy to maximize the reduction of invasiveness. In this study, the feasibility of UroVysion^® fluorescence in situ hybridization (FISH) for the detection of UTUC in 1 mL of selective urine is investigated. Ten consecutive patients with biopsy-proven UTUC and five patients with negative diagnostic ureteroscopy findings were included in this case-control study. During ureteroscopy, 1 mL of selective urine was collected passively with a ureteral splint for Urovysion® FISH. The FISH rater was blinded to any clinical information. The results of FISH were compared to the findings of concomitantly collected selective urine cytology and the patients' UTUC status. FISH was feasible in all samples with a sensitivity of 90% and a specificity of 80% for UTUC. In comparison, selective cytology resulted in a diagnostic yield of 87% with a sensitivity of 80% and a specificity of 67%. In conclusion, UTUC detection is feasible with FISH in 1 mL of passively collected selective urine. Thus from a technical point of view, FISH could be used as an outpatient triage test to decide if follow-up ureteroscopy is necessary after kidney-sparing surgery of UTUC. Evaluation of the diagnostic accuracy of FISH for the suggested pathway deserves further attention.

The Paris System for Reporting Urinary Cytology: early review of the literature reveals successes and rare shortcomings

The Paris System for Reporting Urinary Cytology (TPS) provides recommendations for the diagnosis of urinary tract cytology (UTC) specimens and has found acceptance on an international level. Since the official release of TPS in 2016, numerous research studies have been published analyzing its impact. This review summarizes the studies published since the release of TPS, highlighting areas in which TPS has performed well and other areas in which TPS may need improvement.

Improved correlation of urinary cytology specimens using The Paris System in biopsy-proven upper tract urothelial carcinomas

BACKGROUND

Urine cytology specimens are essential for screening and monitoring high-grade urothelial carcinomas. However, inconsistent reporting and equivocal diagnostic categories have remained a challenge. The Paris System for Reporting Urinary Cytology (TPS) was developed to provide clear cytomorphologic criteria for urine cytology specimens. Significant correlation between the surgical biopsy diagnosis (SD) and TPS diagnosis (PD) has been established in lower urothelial tract carcinomas, but to the authors' knowledge limited information is available regarding upper urinary tract carcinomas.

METHODS

A total of 56 cytology specimens from 35 patients within 90 days of an SD of upper urinary tract carcinoma were included. Cytology was re-reviewed and assigned a PD. The original diagnosis (OD) and PD were compared with the corresponding SD to determine which correlated best.

RESULTS

The PD corresponded to the SD in 35 of 56 cases (63%), which was greater than that for the OD and SD, which were concordant in 19 of 56 cases (34%). Both the OD and PD were concordant in 18 of 56 cases (32%), and neither corresponded in 20 of 56 cases (36%). A total of 27 of 33 cases of high-grade urothelial carcinoma/carcinoma in situ on SD (82%) were identified using the PD whereas only 15 cases (45%) were identified with the OD. The number of "atypical" diagnoses in the OD was reduced from 16 of 56 cases (29%) to 7 of 56 cases (13%) using the PD. Of the 14 of 56 "negative" OD (25%), only 4 remained after implementation of the PD. A diagnosis of low-grade urothelial neoplasm was established in 6 of 20 cases (30%) with the PD compared with 3 of 20 cases with the OD (15%).

CONCLUSIONS

The authors found that reclassification with TPS improved correlation with the SD compared with previous methodologies. Specifically, TPS increased the number of high-grade urothelial carcinoma diagnoses and decreased the number of equivocal or "atypical" diagnoses. Cancer Cytopathol 2018. © 2018 American Cancer Society.

Interobserver reproducibility of The Paris System for Reporting Urinary Cytology

BACKGROUND

The Paris System for Reporting Urinary Cytology represents a significant improvement in classification of urinary specimens. The system acknowledges the difficulty in cytologically diagnosing low-grade urothelial carcinomas and has developed categories to deal with this issue. The system uses six categories: unsatisfactory, negative for high-grade urothelial carcinoma (NHGUC), atypical urothelial cells, suspicious for high-grade urothelial carcinoma, high-grade urothelial carcinoma, other malignancies and a seventh subcategory (low-grade urothelial neoplasm).

METHODS

Three hundred and fifty-seven urine specimens were independently reviewed by four cytopathologists unaware of the previous diagnoses. Each cytopathologist rendered a diagnosis according to the Paris System categories. Agreement was assessed using absolute agreement and weighted chance-corrected agreement (kappa). Disagreements were classified as low impact and high impact based on the potential impact of a misclassification on clinical management.

RESULTS

The average absolute agreement was 65% with an average expected agreement of 44%. The average chance-corrected agreement (kappa) was 0.32. Nine hundred and ninety-nine of 1902 comparisons between rater pairs were in agreement, but 12% of comparisons differed by two or more categories for the category NHGUC. Approximately 15% of the disagreements were classified as high clinical impact.

CONCLUSIONS

Our findings indicated that the scheme recommended by the Paris System shows adequate precision for the category NHGUC, but the other categories demonstrated unacceptable interobserver variability. This low level of diagnostic precision may negatively impact the applicability of the Paris System for widespread clinical application.

p16/Ki-67 dual labeling and urinary cytology results according to the New Paris System for Reporting Urinary Cytology: Impact of extended follow-up

BACKGROUND

Overexpression of p16^INK4a has been identified in urothelial malignancies both cytologically and histologically. In addition, p16/Ki-67 dual labeling has been shown to identify high-grade urothelial cancer cells and some progression cases within a 12-month delay. The Paris System for Reporting Urinary Cytology (TPS) was published in late 2015. Its aim is to clarify the criteria for diagnosing or, conversely, excluding high-grade urothelial carcinoma (HGUC).

METHODS

Dual labeling was performed on archived ThinPrep-based Papanicolaou slides. A total of 208 samples (negative for high-grade urothelial carcinoma [NHGUC], 59; consistent with low-grade urothelial neoplasia [LGUN], 24; atypical urothelial cells [AUC], 15; and suspicious for or showing HGUC, 110) were analyzed for p16/Ki-67 after reclassification according to TPS. We assessed the oncologic status of the patients with cystoscopy, urinary cytology, histology, and prolonged 36-month follow-up data.

RESULTS

The sensitivity of p16/Ki-67 for life-threatening lesions was not different from that of urinary cytology (82.8% vs 83.6%; P = 1). However, among patients with samples classified as NHGUC and AUC, disease-free survival was significantly shorter for dual-labeled cases versus cases with negative dual labeling (P < .0001). The same tendency was observed in patients with histologically proven LGUN (P < .0001). As for specificity in patients with negative cystoscopy and cytology combined, prolonged follow-up showed 90% overall survival at 24 months.

CONCLUSIONS

A long-term evaluation of p16/Ki-67 dual labeling may identify HGUC and progression in cases with negative/low-grade urinary cytology results, and there are potential implications for the clinical management of patients after the conservative treatment of non-muscle-invasive urothelial carcinoma. Cancer Cytopathol 2017;125:552-62. © 2017 American Cancer Society.

A review of the Paris system for reporting urinary cytology

After the 2013 International Congress of Cytology in Paris, consensus groups were formed to establish an international reporting system for urinary tract (UT) specimens. The recommended guidelines, known as The Paris System (TPS) for Reporting Urinary Cytology, focus on reducing the rate of unnecessary indeterminate diagnoses while maintaining the excellent performance UT cytology has for identifying high-grade urothelial carcinoma. This review highlights the major features of TPS.

The utility of bronchial brushings in the modern era of flexible bronchoscopy

INTRODUCTION

Bronchoscopic procedures allow for the procurement of cellular material for diagnosis, molecular studies, and staging. Procurement modalities include bronchoalveolar lavage (BAL), bronchial washing (BW), transbronchial ultrasound-guided needle aspiration (TBNA), transbronchial biopsy (TBBX), endobronchial biopsy (EB), and bronchoscopic brushing (BB). These specimens, taken concurrently, often circumvent the need for an open biopsy, and allow for more appropriate and efficient patient management. Although BB is a well-established method for obtaining cytologic material, it often introduces artifacts and may contain abundant material such as benign and/or metaplastic bronchial epithelium, both of which may result in atypical or false-positive diagnoses. We examined the utility of BB specimens at our institution in recent years.

METHODS

210 BB specimens were identified at our institution over a 2-year period, allowing for at least a 2-year follow-up period. The diagnoses were compiled and compared against results from simultaneously obtained BAL, BW, TBNA, TBBX, and EB specimens, as well as any follow-up during the subsequent 2- to 4-year period.

RESULTS

BB specimens were diagnosed as malignant (n = 44), benign (130), indeterminate (30), and non-diagnostic (6). There were no false-positive diagnoses. There were 6 instances in which malignancy was not definitively diagnosed on a non-BB specimen but definitively diagnosed on BB.

CONCLUSION

BB specimens rarely provide the only diagnostic material during a bronchoscopic procedure, though they possess excellent specificity for malignancy. Indeterminate diagnoses have a positive predictive value of approximately 73%.

Application of The Paris System to atypical urine cytology samples: correlation with histology and UroVysion® FISH

OBJECTIVES

To evaluate whether atypical urine cytology cases may be stratified more objectively using The Paris System (TPS) and whether reclassified cases correlate with histology and UroVysion^® results.

METHODS

Atypical urine cytology cases subjected to UroVysion^® testing over a period of 6 years were reviewed. Each case was reclassified according to TPS and correlated with histology and UroVysion^® results.

RESULTS

A total of 91 cases were identified; 70.3% were reclassified as 'negative for high-grade urothelial carcinoma (HGUC)' and 14.3% as 'atypical urothelial cells (AUC)'. The histological correlation was available in 45 cases. In the 'negative for HGUC' category, 67.9% had no histological evidence of malignancy, but 17.9% were diagnosed as HGUC. In the 'AUC' category, histology revealed urothelial carcinoma in 70% of the cases (of these, 71.4% were high grade). There was no histological evidence of malignancy in 30% of cases; notably, all of which were from patients under surveillance. The sensitivity and specificity of UroVysion^® were 85.7% and 33.3% in the 'AUC' group and 62.5% and 100% in the 'negative for HGUC' group.

CONCLUSIONS

The Paris System is an objective template for reporting urine cytology specimens, and is particularly useful in identifying HGUC cases and refining the category of 'AUC'.

Impact of Implementing the Paris System for Reporting Urine Cytology in the Performance of Urine Cytology: A Correlative Study of 124 Cases

OBJECTIVES

We assessed the performance of urine cytology using the Paris System for Reporting Urine Cytology (PSRUC) in comparison to our current system.

METHODS

In total, 124 specimens with histologic correlation were reviewed and assigned to the PSRUC categories: benign, atypical urothelial cells (AUCs), suspicious for high-grade urothelial carcinoma (SHGUC), and high-grade urothelial carcinoma (HGUC). Original cytological diagnoses were recorded.

RESULTS

Fewer cases were given an AUC diagnosis using the PSRUC in comparison to the original diagnoses (26% vs 39%), while the association of AUCs with subsequent HGUC increased from 33% to 53% with the PSRUC. Using the PSRUC resulted in a higher number of low-grade carcinomas assigned to the benign (40%) rather than the AUC (22%) category. The performance of SHGUC/HGUC diagnoses was similar in both systems (predictive value = 94%).

CONCLUSIONS

The PSRUC seems to improve the performance of urine cytology by limiting the AUC category to cases that are more strongly associated with HGUC.

ImmunoCyt test compared to cytology in the diagnosis of bladder cancer: A meta-analysis

The aim of the present study was to evaluate the diagnostic value of the ImmunoCyt test compared with urine cytology in detecting bladder cancer. A systematic literature search was performed to locate all publications reporting on the diagnostic accuracy of the ImmunoCyt test for bladder cancer. Data were extracted from 2×2 tables or calculated from reported accuracy data. Collected data were meta-analyzed for sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and summary receiver operator characteristic (sROC) curve analysis. We applied the Meta-DiSc 1.4 and STATA 13.0 software to the meta-analysis. Seven separate studies consisting of 1,602 patients with bladder cancer were considered in the meta-analysis. We found that the ImmunoCyt test had a higher sensitivity than the urine cytology test [0.725, 95% confidence interval (CI) 0.683-0.765 vs. 0.566, 95% CI, 0.521-0.611], but the specificity, positive LR, negative LR, DOR, area under the curve (AUC) and Q index of the ImmunoCyt test were lower compared with the urine cytology test. In addition, the pooled sensitivity, specificity, positive LR, negative LR, DOR, AUC, and Q index of the combined method (combination of ImmunoCyt and cytology) were 0.833, 0.644, 2.804, 0.228, 13.50, 0.8554 and 0.7863, respectively. The results of the Eggers test showed no publication bias (P>0.05). In conclusion, specificity, positive LR, negative LR, DOR, the AUC, and the Q index of the urine cytology test may be superior to the ImmunoCyt test, but the ImmunoCyt test has greater sensitivity than the urine cytology test. Use of ImmunoCyt and cytology in combination has the potential to improve the sensitivity and promises to be an alternative in the detection of bladder cancer.

Subclassifying atypia in urine cytology: what are the helpful features?

INTRODUCTION

The diagnosis "atypical urothelial cells (AUC)" remains an unresolved problem, making many urologists dissatisfied and confused about the management strategy on these cases. To date, a few inspiring attempts were made to subclassify AUC into "atypical urothelial cells of undetermined significance" (AUC-US) and "atypical urothelial cells cannot exclude high grade" (AUC-H). The aim of our study was to investigate the most predictive for high-grade urothelial carcinoma (HGUC) cytomorphologic parameters and whether the proposed classification can be implemented in our institution.

MATERIAL AND METHODS

The electronic medical record system was searched for cytology specimens that were diagnosed as AUC from January 1, 2005 to March 1, 2013 and their relative clinical-pathological follow-up. All specimens were reviewed by an experienced cytopathologist by using 20 published "most predictive" for HGUC criteria.

RESULTS

A total of 162 AUC specimens were reclassified into 3 groups: AUC-H (n = 45), AUC-US (n = 51), and "negative for malignancy" (n = 66). The reclassification of AUC-H and "negative for malignancy" had 79% sensitivity, 77% specificity, 60% positive predictive value, and 89% negative predictive value to histologically proven HGUC diagnosis.

CONCLUSIONS

Our study demonstrated a good correlation between the presence of "HGUC-predictive" cytologic criteria and the final biopsy-proven HGUC in cytologic cases originally diagnosed as "atypical urothelial cells present." We identified 2 of the most predictive for HGUC on follow-up cytomorphologic parameters such as increased nuclear-cytoplasmic ratio >0.7 and coarse chromatin (16 abnormal cells per slide in average). These parameters, along with positive fluorescent in situ hybridization results can help during cytologic evaluation of urine specimens.

Urine cytology: does the number of atypical urothelial cells matter? A qualitative and quantitative study of 112 cases

INTRODUCTION

This study presents a detailed and systematic morphological and quantitative analysis of urine cytology specimens in order to determine which qualitative and quantitative features are mostly associated with high-grade urothelial carcinoma (HGUCA).

MATERIAL AND METHODS

This study included 112 urine cytology cases with a surgical follow-up within 1 year that were originally reported as "atypical," "suspicious for HGUCA," or "positive for HGUCA." The morphological characteristics as well as the number of abnormal cells were correlated with a diagnosis of HGUCA on follow-up biopsy.

RESULTS

Multivariate analysis showed that the presence of hyperchromatic atypical cells with nuclear-cytoplasmic ratio ≥ 0.7 was an independent predictor of HGUCA. Similarly, irregular nuclear membranes, single cells, and pleomorphism correlated with surgical outcome whereas eccentric nuclear location, prominent nucleoli, nuclear-cytoplasmic ratio between 0.5 and 0.7 did not. Cases with ≤10 atypical cells had significantly lower rates of subsequent HGUCA than did those with >10 atypical cells (58% versus 77%). Cases with ≤5 atypical cells (n = 26) showed similar prediction rates (58%) for HGUCA than did those with 6 to 10 atypical cells (n = 12).

CONCLUSIONS

The number of atypical urothelial cells is an important criterion that should be taken into account when assigning cases to the "positive" or the "suspicious" categories. A preliminary cutoff of 10 cells appears to be easily applicable and valid from the clinical standpoint.

Benign-appearing urothelial tissue fragments in noninstrumented voided urine specimens are associated with low rates of urothelial neoplasia

BACKGROUND

The presence of urothelial tissue fragments (UTF) in voided urine (VU) is often considered an abnormal finding that may be associated with the presence of urothelial papillary neoplasms. In the current study, the authors reviewed VU specimens containing benign-appearing UTF (BUTF) to determine the associated rate of urothelial neoplasia at the study institution.

METHODS

A retrospective search of the electronic pathology database system over a 5-year period (2009-2013) revealed 1131 VU specimens containing UTF. Of these, 459 cases (40.6%) did not have a recent history of instrumentation. Fifteen cases were excluded because the slides were not available for review. In the remaining 444 cases, 274 cases (61.7%) had BUTF. A total of 170 cases (38.3%) had UTF with atypical cytologic features and were therefore excluded.

RESULTS

Of the 274 cases, 29 (10.6%) had follow-up surgical pathology specimens available. The overall rate of urothelial neoplasia on follow-up was 3.6% for low-grade urothelial neoplasia (10 cases) and 0.7% for high-grade urothelial carcinoma (2 cases). Forty-five cases (16.4%) were determined to have urinary tract stones on follow-up.

CONCLUSIONS

The presence of BUTF in VU specimens requires careful examination of the medical history because their presence may be explained by recent instrumentation. If recent instrumentation is not identified, the etiology of BUTF is not usually determined; in the current study, BUTF were found to be associated with urinary tract stones in 16.4% of cases. They also present a low risk of low-grade urothelial neoplasia (3.6%) and high-grade urothelial carcinoma (0.7%) when compared with the overall benign category at the study institution (2.3% [P =.15] and 0.7%, respectively).

Atypical urothelial tissue fragments in noninstrumented voided urine specimens are associated with low but significantly higher rates of urothelial neoplasia than benign-appearing urothelial tissue fragments

BACKGROUND

The interpretation of urothelial tissue fragments (UTF) in voided urine (VU) specimens is controversial. If UTF contain cytomorphologically atypical cells, the diagnosis often becomes more challenging. The authors previously analyzed the outcome of patients with benign-appearing UTF in 274 noninstrumented VU specimens. In this retrospective study, noninstrumented VU specimens containing UTF with atypical cytomorphological features (AUTF) were evaluated and compared with the previous results.

METHODS

The Johns Hopkins Hospital electronic pathology database was searched for VU cases containing UTF over a 5-year period.

RESULTS

A total of 170 noninstrumented VU specimens containing AUTF were identified. Twenty-four specimens had subsequent or coincidental surgical pathology specimens with the following overall rates of neoplasia: high-grade urothelial carcinoma: 8.8% (15 specimens), low-grade urothelial neoplasia: 1.2% (2 specimens), and prostate carcinoma invading the bladder: 0.6% (1 specimen). A total of 49 specimens (28.8%) were diagnosed with urolithiasis on follow-up. Twenty-five cases had follow-up cytology specimens, all of which were negative for malignancy. Of 72 cases without histopathologic, radiologic, or cytopathologic follow-up, 62 (86.1%) had a mean clinical follow-up of 22.5 months and 10 cases did not have clinical follow-up.

CONCLUSIONS

The presence of AUTF in noninstrumented VU is associated with low rates of urothelial neoplasia but a statistically higher risk of urothelial neoplasia than the presence of BUTF (10.0% vs 4.4%; P<.05). In particular, the rate of high-grade urothelial carcinoma is significantly higher in noninstrumented VU specimens containing AUTF than those containing BUTF (8.8% vs 0.7%; P<.0001). In addition, urolithiasis is associated with AUTF in a substantial percentage of noninstrumented VU specimens.

Accuracy and risk of malignancy for diagnostic categories in urine cytology at a large tertiary institution

BACKGROUND

At a high-volume center, it became necessary to provide benchmarks for the accuracy and risk of malignancy per urine cytology diagnostic category. The additive sensitivity for the determination of the residual risk of disease was calculated with the goal of determining the performance of cytology and optimal triage, including the number of urine samples, before the detection of malignancy in surveillance patients.

METHODS

A 2-year laboratory information system-based search was conducted, and it yielded 587 subjects (695 biopsy and cytology pairs) with histological follow-up. The sensitivity and specificity of cytology for urothelial malignancy, the risk of malignancy per diagnostic category, the additive sensitivity, and the time for conversion from a negative initial cytology result to a positive cytology result were examined.

RESULTS

The overall average sensitivity and specificity of cytology were 48.9% and 83.0%, respectively. The additive sensitivity increased with each subsequent cytology and peaked with the third cytology. A median conversion time of 22.2 months from a negative initial cytology result to a positive cytology result and a decline in predictive positive cytology after the fourth cytology were noted. Subcategorization of the atypical category failed to show statistical significance in predicting outcomes of biopsy. Surveillance subjects, as compared to primary subjects, showed a higher sensitivity for the detection of high and low grade cancers.

CONCLUSIONS

The findings suggest that atypia favoring malignancy is being appropriately flagged. However, further definition of the atypical category is needed to increase specificity with a better qualitative or quantitative morphological algorithm. This study provides a risk of malignancy for each category for benchmarking and clinical triage. The data suggest that follow-up should include at least 4 consecutive urine specimens over a period of 22.2 months.

Atypical urine cytology and the Johns Hopkins Hospital template: the University of Chicago experience

INTRODUCTION

The rate of atypical diagnoses in urine cytology can be high depending on the screening population. Unlike thyroid and cervical cytology, there is a lack of standardized criteria to stratify them into more clinically meaningful categories.

MATERIALS AND METHODS

A set of diagnostic criteria described by Johns Hopkins Hospital (JHH) provided a tool to divide atypical urine specimens into those that were low risk and those likely to be predictive of high-grade urothelial carcinoma (HGUC). In this study, the JHH template was applied to a cohort of atypical urine cytology specimens from the University of Chicago (U of C) to compare it to existing U of C terminology and determine whether it should be formally adopted.

RESULTS

Sixty-eight percent of patients classified as atypical urothelial cells, favor high-grade lesion (AUC-H) were diagnosed with HGUC during the study. Correlation was noted between the JHH diagnostic categories and the U of C diagnostic categories, with 49% of patients reclassified as AUC-H being diagnosed with atypical urothelial cells, suspicious for neoplasia and 83% of cases of patients reclassified as atypical urothelial cells of unknown significance being diagnosed as atypical, urothelial cells. The JHH category of AUC-H had a higher positive predictive value for HGUC than the U of C category atypical urothelial cells, suspicious for neoplasm did (69% versus 58%, p = 0.0087). Unlike the JHH study, AUC-H showed higher correlation with HGUC in the hematuria group (90%) than in the surveillance group (66%).

CONCLUSIONS

JHH criteria demonstrated a higher rate of predicting HGUC than U of C diagnostic categories, supporting the adoption of these criteria at U of C.

Significance of atypical category in voided urine specimens prepared by liquid-based technology: Experience of a single institution

INTRODUCTION

The goal of this study was to evaluate the clinical significance of atypical cytology in voided urine samples. We also studied any differences in outcome that may exist between the patients being surveyed versus high risk for urothelial carcinoma (UC).

MATERIALS AND METHODS

This was a retrospective study of all voided urine specimens with "atypical" cytology over a 10-year period. The patients were categorized into those with and without a prior diagnosis of UC as the "surveillance" and "de novo" (DG) groups. Follow-up was obtained. Clinical impact and outcomes of the 2 groups were compared.

RESULTS

In this study, 5.7% of voided urine specimens were atypical. Mean age of patients in years, male/female ratio, and time to diagnosis in days was 59 versus 71, 23:15 versus 22:1, and 95 versus 43 in the DG and surveillance group, respectively. Rate of progression to UC was similar in both groups. High-grade UC was significantly higher in the DG.

CONCLUSIONS

Approximately 20% of patients in the DG were subsequently diagnosed with UC. The common causes for the atypical diagnosis that did not progress to UC were stones and benign prostatic hyperplasia. In the absence of an etiology for the atypia, further investigations are warranted.

Considerations on the use of urine markers in the management of patients with low-/intermediate-risk non-muscle invasive bladder cancer

OBJECTIVES

Many molecular assays for bladder cancer diagnosis and surveillance have been developed over the past several decades. However, none of these markers have been routinely implemented into clinical decision making. Beyond their potential for screening high-risk populations, urine markers likely have the greatest potential in the follow-up of patients with non-muscle invasive bladder cancer (NMIBC).

METHODS

Here, we discuss the current options and limitations of the use of urine markers for patient surveillance, focusing on patients with low-/intermediate-risk NMIBC.

RESULTS

As these patients have a very low risk of tumor progression, the primary goal of surveillance is detection of recurrent disease. Although urine cytology seems to be limited to detection of few patients who would develop high-grade tumors, we conclude that the use of markers with high sensitivity for low-grade disease for patient follow-up has the potential to decrease the frequency of urethrocystoscopy without compromising patient prognosis. Because a single marker may not have sufficient sensitivity for detection of low-grade tumors, different scenarios, e.g., multitesting and reflex or sequential approaches, are discussed.

CONCLUSIONS

There is consensus that currently available markers have the potential to support clinical decision making in follow-up of patients with low-/intermediate-risk NMIBC. In light of our analysis, further additional randomized controlled studies to effectively assess the clinical usefulness of modern urine markers are required.

A novel precision-engineered microfiltration device for capture and characterisation of bladder cancer cells in urine

BACKGROUND

Sensitivity of standard urine cytology for detecting urothelial carcinoma of the bladder (UCB) is low, attributable largely to its inability to process entire samples, paucicellularity and presence of background cells.

OBJECTIVE

Evaluate performance and practical applicability of a novel portable microfiltration device for capture, enumeration and characterisation of exfoliated tumour cells in urine, and compare it with standard urine cytology for UCB detection.

METHODS

A total of 54 urine and bladder wash samples from patients undergoing surveillance for UCB were prospectively evaluated by standard and microfilter-based urine cytology. Head-to-head comparison of quality and performance metrics, and cost effectiveness was conducted for both methodologies.

RESULTS

Five samples were paucicellular by standard cytology; no samples processed by microfilter cytology were paucicellular. Standard cytology had 33.3% more samples with background cells that limited evaluation (p<0.001). Microfilter cytology was more concordant (κ=50.4%) than standard cytology (κ=33.5%) with true UCB diagnosis. Sensitivity, specificity and accuracy were higher for microfilter cytology compared to standard cytology (53.3%/100%/79.2% versus 40%/95.8%/69.9%, respectively). Microfilter-captured cells were amenable to downstream on-chip molecular analyses. A 40 ml sample was processed in under 4 min by microfilter cytology compared to 5.5 min by standard cytology. Median microfilter cytology processing and set-up costs were approximately 63% cheaper and 80 times lower than standard cytology, respectively.

CONCLUSIONS

The microfiltration device represents a novel non-invasive UCB detection system that is economical, rapid, versatile and has potentially better quality and performance metrics than routine urine cytology, the current standard-of-care.