A systematic review on performance characteristics of FNA of renal lesions: It is time for a standardized classification system.

BACKGROUND: The incidence of renal tumors has steadily increased over the past decade. In this study, the authors performed a systematic review and analysis of the literature on renal fine-needle aspiration (FNA) to determine its performance and explore whether a standardized classification system can be used for reporting renal FNA cytology. METHODS: A systematic search of published articles on renal FNA was conducted. The data on FNA and histologic diagnosis were extracted and categorized, and the risk of malignancy was calculated. Different scenarios were used to estimate FNA performance statistics. RESULTS: Of the 3766 potentially relevant studies, 23 met the inclusion criteria of the study. The 2231 FNA cases included were re-categorized according to the classification system, rendering 142 (6.36%) nondiagnostic, 270 (12.1%) nonneoplastic, 271 (12.14%) benign neoplasm, 65 (2.91%) renal neoplasm with unknown malignant potential, oncocytic type, 25 (1.12%) atypia of undetermined significance, 60 (2.68%) suspicious for malignancy, and 1398 (62.66%) malignant FNA diagnoses. The risk of malignancy in these cases was 65.4%, 18.1%, 16.6%, 16.9%, 60%, 73.3%, and 96.9%, respectively. According to the classification system, the study indicated that the accuracy of renal FNA was between 91% and 95%, the sensitivity was 90.9%-96.7%, and the specificity was 82%-92% in different scenarios. CONCLUSIONS: There is a need for a standardized reporting in renal cytology that will improve the sensitivity and accuracy of renal cytology, reduce the rate of indeterminate diagnoses, and alter the management strategies of renal lesions. Based on the available literature, a new reporting system is proposed, including categories with an associated risk of malignancy.

American Society of Cytopathology Telecytology validation recommendations for rapid on-site evaluation (ROSE).

Telecytology has multiple applications, including rapid onsite evaluation (ROSE) of fine-needle aspiration (FNA) specimens. It can enhance cytopathology practice by increasing productivity, reducing costs, and providing subspecialty expertise in areas with limited access to a cytopathologist. However, there are currently no specific validation guidelines to ensure safe practice and compliance with regulations. This initiative, promoted by the American Society of Cytopathology (ASC), intends to propose recommendations for telecytology implementation. These recommendations propose that the validation process should include testing of all hardware and software, both separately and as a whole; training of all individuals who will participate in telecytology with regular competency evaluations; a structured approach using retrospective slides with defined diagnoses for validation and prospective cases for verification and quality assurance. Telecytology processes must be integrated into the laboratory's quality management system and benchmarks for discrepancy rates between preliminary and final diagnoses should be established and monitored. Special attention should be paid to minimize discrepancies that downgrade malignant cases to benign (false positive on telecytology). Currently, billing and reimbursement codes for telecytology are not yet available. Once, they are, recommendation of the appropriate usage of these codes would be a part of the recommendations. These proposed guidelines are intended to be a resource for laboratories that are considering implementing telecytology. These recommendations can help to ensure the safe and effective use of telecytology and maximize its benefits for patients.

Cytologic-Histologic Correlation Practices for Nongynecologic Cytology Specimens: A Survey by the College of American Pathologists Cytopathology Committee.

CONTEXT.­: Cytologic-histologic correlation (CHC) is a Clinical Laboratory Improvement Amendments-mandated requirement for gynecologic cytology, but no similar requirement exists for nongynecologic cytology. This study presents the findings from a College of American Pathologists' survey of nongynecologic cytology practice patterns. OBJECTIVE.­: To survey the current CHC practices for nongynecologic cytology. DESIGN.­: Data were analyzed from a survey developed by the committee and distributed to participants in the Nongynecologic Cytopathology Education Program mailing. RESULTS.­: Adoption of CHC for nongynecologic cytology cases is worldwide, with 88.5% of institutions performing CHC on these specimens, a substantial increase from previous years. Performance of CHC varied by institution type, with clinic or regional/local independent laboratories and national/corporate laboratories performing CHC significantly less frequently than hospitals, university hospitals/academic medical centers, and Veterans Administration/Department of Defense hospital institutions. Most CHC was performed concurrently in real time, when the corresponding surgical specimen was reviewed. Selection for real-time concurrent CHC was by the interpreting pathologist, the pathologist diagnosing the surgical biopsy sample or cytopathology case, or both. Sampling was by far the most common reason for discordance. A 2-step difference was the most frequent threshold for discordance between cytology and surgical specimens, but this criterion varied among institutions, with no majority definition. The positive predictive value of a positive cytology finding was calculated rarely in North American institutions but was calculated more frequently in international institutions. CONCLUSIONS.­: CHC practices for nongynecologic cytopathology mirror those found for CHC of gynecologic cytopathology.

An Atypical Presentation of Hepatocellular Carcinoma with Multisite Metastasis following a Curative Liver Transplant.

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy, and liver transplantation is usually curative. HCC recurrences are rare after curative treatment options, although they are prevalent depending on various risk factors. We present a 71-year-old female patient with an unusual pattern of disease progression following a curative liver transplant with a metastatic presentation in the absence of alpha-fetoprotein elevation after 3 years of disease-free clinical presentation. We present this case to emphasize the importance of intermittent cross-sectional imaging in addition to ultrasound screening in HCC surveillance.

Current State of Cytologic-Histologic Correlation Implementation for North American and International Laboratories: Results of the College of American Pathologists Cytopathology Committee Laboratory Practices in Gynecologic Cytology Survey.

CONTEXT.­: The College of American Pathologists (CAP) updated the Laboratory Accreditation Program Cytopathology Checklist to assist laboratories in meeting and exceeding the Clinical Laboratory Improvement Amendments standards for gynecologic cytologic-histologic correlation (CHC). OBJECTIVE.­: To survey the current CHC practices. DESIGN.­: Data were analyzed from a survey developed by the committee and distributed to participants in the CAP Gynecologic Cytopathology PAP Education Program mailing. RESULTS.­: Worldwide, CHC practice is nearly universally adopted, with an overall rate of 87.0% (568 of 653). CHC material was highly accessible. CHC was commonly performed real time/concurrently at the time the corresponding surgical pathology was reviewed. Investigation of CHC discordances varied with North American laboratories usually having a single pathologist review all discrepant histology and cytology slides to determine the reason for discordance, while international laboratories have a second pathologist review histology slides to determine the reason for discordance. The cause of CHC discordance was primarily sampling issues. The more common statistical metrics for CHC monitoring were the total percentage of cases that correlated with subsequent biopsies, screening error rate by cytotechnologist, and interpretative error rate by cytotechnologist. CONCLUSIONS.­: Many laboratories have adopted and implemented the CHC guidelines with identifiable differences in practices between North American and international laboratories. We identify the commonalities and differences between North American and international institutional practices including where CHC is performed, how CHC cases are identified and their accessibility, when CHC is performed, who investigates discordances, what discordances are identified, and how the findings affect quality improvement.

Splenogonadal Fusion: A Rare Mimicker of Malignancy.

Splenogonadal fusion is a rare congenital anomaly in which ectopic splenic tissue is found in the testis and can present as a testicular mass mimicking a testicular malignancy. We present a 27-year-old male who presented with a palpable left testis mass suspicious for malignancy and ultimately found to have discontinuous splenogonadal fusion after radical orchiectomy.

Telecytology validation: is there a recipe for everybody?

INTRODUCTION: Telecytology offers a suitable solution to the cost and time efficiency questions on rapid onsite evaluation (ROSE). An increasing number of institutions are adopting new telecytology systems to meet the increasing ROSE requests, although there is no agreement on the details of how a telecytology validation study needs to be conducted. We propose a standardized approach for telecytology validation studies that could be done in a variety of practices. MATERIALS AND METHODS: Consecutive cases from 6 months prior were chosen to reflect a case mix comparable to real life. A fellow assessed the slides at the ROSE site while 6 cytopathology faculty convened in a conference room with a television screen, and noted the adequacy, diagnostic category, and specific diagnoses. All participants were blinded to the original adequacy assessment and final diagnoses. For each case, evaluation time and the slides counts were noted. RESULTS: Fine-needle aspiration specimens from 52 patients were included in the study. Of these, 13 cases were used in the first "test" session. The adequacy concordance rates ranged between 92.3% and 100%, with an overall concordance rate of 94.8%. The diagnostic category concordance rates ranged between 90.3% and 95.5%, with an overall concordance rate of 91.9%. The specific diagnosis concordance rates ranged between 84.6% and 92.9%, with an overall concordance rate of 88.1%. CONCLUSIONS: Validation of telecytology requires a standardized approach just like any other new technology. In this study, we propose an efficient and accurate method for cytopathology departments of various case volumes to conduct telecytology validation studies.

Adrenal gland cytology reporting: a multi-institutional proposal for a standardized reporting system.

BACKGROUND: With the development of new technologies and the changing patient profiles, cytopathology departments receive increasing numbers of adrenal gland cytology specimens. In this study, the authors analyzed archival adrenal gland cytology cases and attempted to implement a diagnostic reporting system. DESIGN: Retrospective electronic medical record search was performed for adrenal gland cytology specimens in seven tertiary care centers. The cytology diagnoses were grouped in 7 categories: nondiagnostic, nonneoplastic, benign adrenal cortical elements (BACE), primary neoplasm of noncortical origin (NONC), atypia of undetermined significance (AUS), suspicious for malignancy (SM), and malignant (MAL). If available, histopathology results of concurrent and/or follow-up biopsies and/or resections were documented. RESULTS: A total of 473 adrenal gland cytology cases were included. BACE cases comprised 21.8%, whereas MAL cases were 57.5% of all cases. For BACE and MAL categories, there were 100% and 98.9% correlation, respectively, in the cases with histopathology follow-up. Six of 10 NONC cases had histopathology diagnoses and there were 3 pheochromocytomas and 3 schwannomas. Twenty-one AUS cases had histology follow-up and 10 (47.6%) of them were malignant. Six cases of SM had histopathology follow-up, and all of them were malignant on the follow-up. CONCLUSIONS: The authors propose a 7-tier diagnostic scheme for adrenal gland cytology. The risk of malignancy was 98.9% in MAL cases (87/88) in the cohort. The only case with discordance was reported as "adrenal cortical adenoma with marked atypia"' on resection. There was no difference between endoscopic ultrasound-guided and percutaneous methods. Further studies are needed to validate and make this approach universal.

Digital image analysis of high-grade urothelial carcinoma in urine cytology confirms chromasia heterogeneity and reveals a subset with hypochromatic nuclei and another with extremely dark or "India ink" nuclei.

BACKGROUND: The Paris System for Reporting Urinary Cytology (TPS) uses hyperchromasia as major diagnostic criterion for high-grade urothelial carcinoma (HGUC). The purpose of the study was to evaluate cases that were diagnosed as HGUC by TPS and determine whether there are different chromatin distribution patterns (ie, subsets). METHODS: Digital image annotations were performed on microscopic images of HGUC urine specimens with surgical biopsy/resection follow-up. Median gray values were generated for each cell. Neutrophils (polymorphonuclear leukocyte [PMN]) were also enumerated in each case to serve as an internal control. A HGUC/PMN ratio was generated for each case, and the cases were distributed. RESULTS: Sixty-nine HGUC cases yielded 2660 cells, including 2078 HGUC (30.1 cells/case) and 582 PMNs (8.4 cells/case). The average median gray value of an HGUC was 50.6 and of a PMN was 36.8 (P < .0001). Eight of 69 cases (11.6%) contained nuclei that, on average, were darker than or as dark as a PMN (extremely dark, ie, "India ink"). Fifty-one of 69 cases (74.0%) contained nuclei that, on average, were slightly brighter than a PMN (hyperchromatic). Ten of 69 cases (14.5%) contained nuclei that, on average, were much brighter than a PMN (hypochromatic). Within a single case, all cases showed heterogeneity with the hypochromatic cases showing the most dramatic effect. CONCLUSIONS: Digital image analysis reveals that there are large variations in chromasia between cases including a subset of cases with hypochromasia and another with extremely dark or "India ink" nuclei. There was much heterogeneity of chromasia seen within a single sample.

Unusual presentation of adrenal hemangioma as an incidental large adrenal hematoma - A case report.

Adrenal hemangiomas are exceedingly rare benign tumors. Hemangiomas are commonly found in the skin and liver. When they arise in the adrenal gland, they are typically found incidentally on imaging, large size at presentation and are usually surgically resected in view of their large size and heterogeneous imaging appearance. We present a 66-year-old female who presented with right abdominal pain and weight loss and was found to have a large adrenal hematoma arising from a hemangioma.

Application of the Milan System for Reporting Salivary Gland Cytopathology in pediatric patients: An international, multi-institutional study.

BACKGROUND: Pediatric salivary gland fine-needle aspiration (FNA) is uncommon with a higher frequency of inflammatory lesions and a small proportion of malignancies. This international, multi-institutional cohort evaluated the application of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) and the risk of malignancy (ROM) for each diagnostic category. METHODS: Pediatric (0- to 21-year-old) salivary gland FNA specimens from 22 international institutions of 7 countries, including the United States, England, Italy, Greece, Finland, Brazil, and France, were retrospectively assigned to an MSRSGC diagnostic category as follows: nondiagnostic, nonneoplastic, atypia of undetermined significance (AUS), benign neoplasm, salivary gland neoplasm of uncertain malignant potential (SUMP), suspicious for malignancy (SM), or malignant. Cytology-histology correlation was performed where available, and the ROM was calculated for each MSRSGC diagnostic category. RESULTS: The cohort of 477 aspirates was reclassified according to the MSRSGC as follows: nondiagnostic, 10.3%; nonneoplastic, 34.6%; AUS, 5.2%; benign neoplasm, 27.5%; SUMP, 7.5%; SM, 2.5%; and malignant, 12.4%. Histopathologic follow-up was available for 237 cases (49.7%). The ROMs were as follows: nondiagnostic, 5.9%; nonneoplastic, 9.1%; AUS, 35.7%; benign neoplasm, 3.3%; SUMP, 31.8%; SM, 100%; and malignant, 100%. Mucoepidermoid carcinoma was the most common malignancy (18 of 237; 7.6%), and it was followed by acinic cell carcinoma (16 of 237; 6.8%). Pleomorphic adenoma was the most common benign neoplasm (95 of 237; 40.1%). CONCLUSIONS: The MSRSGC can be reliably applied to pediatric salivary gland FNA. The ROM of each MSRSGC category in pediatric salivary gland FNA is relatively similar to the ROM of each category in adult salivary gland FNA, although the reported rates for the different MSRSGC categories are variable across institutions.

Cytopathology fellowship recruitment: Has the time come to consider a unified approach?

INTRODUCTION: Cytopathology (CYP) fellowship training is a critical component of maintaining a skilled group of cytopathologists. For years, the recruitment process for CYP fellowship programs has remained unchanged, with individual programs outlining their own requirements and timeline, and applicants bearing the cost of travel and dealing with the variable processes outlined by individual programs. However, there has been renewed interest in analyzing the recruitment process for CYP fellowships to look for areas of potential improvement and uniformity. METHODS: With the goal of gauging the interest of CYP fellowship program directors (PDs) in a more unified approach to recruitment or a formal match process, the ASC Cytopathology Program Directors Committee (CPDC) surveyed PDs via SurveyMonkey and organized special webinars with polling over a 4-year time frame (2017-2021), and examined Qualtrics survey data collected by the American Board of Pathology (ABPath) in 2020. RESULTS: The response rate for PDs was greatest in a formal survey by the ABPath (66 respondents; 71% of PDs) conducted in 2020, and lower for an ASC survey in 2021 (61 respondents, 66% of PDs) and 2017 (19 respondents; 21% of PDs) and two recent ASC webinars (10 and 26 respondents; 11% and 28% of PDs). Support for a fellowship match process varied from 29% to 77%, respondent uncertainty ranged from 13% to 50%, and a lack of support ranged from 10% to 60%. In aggregate, approximately 56% of respondents would be in favor of a more standardized process. Recently, after hearing about other fellowships experimenting with a standardized process, the interest in a unified approach doubled from approximately 29% to 60%, and the percentage of PDs with uncertainty decreased from 50% to 26%. In the most recent follow up survey, interest reached the highest level of 77% among PDs. CONCLUSIONS: Herein we present several years of feedback from the CYP fellowship PD community regarding a more standardized approach to CYP fellowship recruitment, culminating in the latest survey with 77% of CYP fellowship PDs expressing interest. Thus, details about what a unified timeframe may look like for CYP fellowships is presented to show how this may improve the recruitment process for the mutual benefit for programs and applicants.

Accuracy of Subclassification and Grading of Renal Tumors on Fine Needle Aspiration Cytology Alone.

BACKGROUND: Fine needle aspiration (FNA) of renal masses can distinguish between benign and malignant neoplasms in 73-94% of cases. Previous studies suggested the correct subclassification of renal cell carcinomas (RCCs) by cytomorphology can be achieved in up to 80% of cases. However, as RCCs become increasingly subclassified by molecular signatures, correct subclassification based on cytology alone is increasingly difficult. DESIGN: Two FNA passes (2 stained with Diff-Quik® and 2 with the Papanicolaou method) were performed on all fresh nephrectomy specimens for a 1-year period. There were 30 cases in this study, with 29 primary renal tumors and 1 case of metastatic lung adenocarcinoma. Each case was assigned a random number and came with 2 slides (1 from each staining method). Eight cytopathologists were asked to provide a diagnosis and the World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading if applicable. Fleiss' Kappa and Cohen's Kappa equations were used to look at inter-rater variability. RESULTS: When compared to the surgical pathology diagnosis, the average percent correct diagnosis for all cytopathologist was 35%. Chromophobe RCCs had the best average percent accuracy at 72% followed by clearcell RCC at 48%. Average accuracy for grading RCCs was 40%. Inter-rater variability among the cytopathologists for all RCC diagnoses was fair with a Fleiss' Kappa coefficient of 0.28. For the WHO/ISUP grade, the weighted coefficient for each pathologist ranged from 0.11 to 0.45, ranging from fair to moderate, respectively. CONCLUSIONS: Renal tumors are difficult to classify on cytopathology alone. Core needle biopsy and ancillary studies are necessary if diagnosis will change management.

Five-year retrospective review in gynecologic cytopathology: is it time to amend?

INTRODUCTION: According to the Clinical Laboratory Improvement Amendments 1988 regulations, 5-year retrospective review (5YRR) of normal Papanicolaou tests in patients with a newly diagnosed high grade squamous intraepithelial lesion or above (HSIL+) is mandatory. Since this mandate has been in place, a multitude of changes have taken place in the screening and management guidelines of cervical cancer. The aim of this study is to assess the role of this mandate in our laboratory and to investigate the lessons learned. MATERIAL AND METHODS: The cytopathology electronic database and institutional quality assurance records at Loyola University Medical Center were searched from January 2009 to December 2019 to identify all Papanicolaou tests diagnosed as new "HSIL and above" (HSIL+). Major discrepancy (2+) was defined as initial negative diagnosis changed to HSIL+. RESULTS: A total of 153,083 Papanicolaou tests were performed during this period; out of these, 1452 (0.94%) were diagnosed as HSIL+. A total of 695 HSIL+ Papanicolaou tests had a negative prior Papanicolaou and in 615 of 695 there was agreement with the initial negative diagnosis. In 61 Papanicolaou tests, the initial diagnosis was changed from negative and they were reclassified on review as 3 HSIL, 9 ASC-H, 7 AGC, and 42 ASCUS or LSIL. Major discrepancy rate was calculated as 3 of 695 (0.43%). None required an amended report. CONCLUSIONS: It is important to revisit the 5YRR as a method of implementing the quality indicators in gynecologic cytology so that the process retains its value without overburdening cytology laboratories and personnel.

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.

Assessing the diagnostic accuracy for pleomorphic adenoma and Warthin tumor by employing the Milan System for Reporting Salivary Gland Cytopathology: An international, multi-institutional study.

BACKGROUND: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has established distinct diagnostic categories for reporting cytopathological findings, and each is associated with a defined risk of malignancy (ROM). However, the ROM is applied at the overall category level and is not specific for particular morphological entities within a category. Here, the diagnostic performance of the MSRSGC for pleomorphic adenoma (PA) and Warthin tumor (WT) is reported. METHODS: The pathology archives of 11 institutions from 4 countries were retrospectively searched to identify all salivary gland fine-needle aspiration (FNA) biopsies with a differential or definitive diagnosis of PA or WT and all resection specimens with a diagnosis of PA or WT; only paired cases were included. All FNA diagnoses were retrospectively classified according to the MSRSGC. RESULTS: A total of 1250 cases met the inclusion criteria, and they included 898 PA cases and 352 WT cases. The ROM in the benign neoplasm category was 3.0% and 1.3% for cases with a differential or definitive diagnosis of PA and WT, respectively. The ROM in the salivary gland neoplasm with uncertain malignant potential (SUMP) category was 2.7% and 18.8% for PA and WT, respectively (P = .0277). The diagnostic accuracy for PA and WT was 95.1% and 96.1%, respectively. CONCLUSIONS: The diagnostic accuracy for PA and WT on FNA is high. Furthermore, these findings highlight the difference in the ROMs associated with 2 specific differential diagnoses in the SUMP category: basaloid neoplasms and oncocytoid neoplasms.

Guar bean in urinary cytology: a morphologic pitfall.

INTRODUCTION: Various types of contaminants can be encountered in cytologic specimens. This study describes a vegetable material that we encountered in ileal conduit urine specimens. We aim to describe the cytomorphology and the source of origin of this vegetable material. MATERIAL AND METHODS: The cytology database for the past 5 years (January 2015-April 2020) was searched for ileal conduit urine cytology specimens with a reported vegetable contaminant. The details of the ostomy procedure and device used were recorded. Histologic sections were prepared from the ostomy devices as well as from guar beans and seeds. RESULTS: A total of 17 urinary specimens from 8 patients were identified that showed the presence of a vegetable contaminant. All the patients were using Coloplast (Minneapolis, MN) SenSura Mio ostomy device. The urine cytology showed presence of polygonal thick-walled cells with a dark brown/orange core with irregular outlines. Similar cells were also seen in the histologic sections prepared from the ostomy adhesive and the guar seed and bean. CONCLUSIONS: Guar gum is a naturally occurring hydrocolloid that is used in ostomy wafer adhesives. Correct identification and familiarity with the cytomorphology of the guar cells in samples of ileal conduit urine is essential to avoid a potential diagnostic pitfall when evaluating urine cytology specimens from these diversion specimens.

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.