Diagnostic quality model (DQM): an integrated framework for the assessment of diagnostic quality when using AI/ML.

BACKGROUND: Laboratory medicine has reached the era where promises of artificial intelligence and machine learning (AI/ML) seem palpable. Currently, the primary responsibility for risk-benefit assessment in clinical practice resides with the medical director. Unfortunately, there is no tool or concept that enables diagnostic quality assessment for the various potential AI/ML applications. Specifically, we noted that an operational definition of laboratory diagnostic quality - for the specific purpose of assessing AI/ML improvements - is currently missing. METHODS: A session at the 3rd Strategic Conference of the European Federation of Laboratory Medicine in 2022 on "AI in the Laboratory of the Future" prompted an expert roundtable discussion. Here we present a conceptual diagnostic quality framework for the specific purpose of assessing AI/ML implementations. RESULTS: The presented framework is termed diagnostic quality model (DQM) and distinguishes AI/ML improvements at the test, procedure, laboratory, or healthcare ecosystem level. The operational definition illustrates the nested relationship among these levels. The model can help to define relevant objectives for implementation and how levels come together to form coherent diagnostics. The affected levels are referred to as scope and we provide a rubric to quantify AI/ML improvements while complying with existing, mandated regulatory standards. We present 4 relevant clinical scenarios including multi-modal diagnostics and compare the model to existing quality management systems. CONCLUSIONS: A diagnostic quality model is essential to navigate the complexities of clinical AI/ML implementations. The presented diagnostic quality framework can help to specify and communicate the key implications of AI/ML solutions in laboratory diagnostics.

Integrating digital pathology into clinical practice.

The field of anatomic pathology has been evolving in the last few decades and the advancements have been largely fostered by innovative technology. Immunohistochemistry enabled a paradigm shift in discovery and diagnostic evaluation, followed by booming genomic advancements which allowed for submicroscopic pathologic characterization, and now the field of digital pathology coupled with machine learning and big data acquisition is paving the way to revolutionize the pathology medical domain. Whole slide imaging (WSI) is a disruptive technology where glass slides are digitized to produce on-screen whole slide images. Specifically, in the past decade, there have been significant advances in digital pathology systems that have allowed this technology to promote integration into clinical practice. Whole slide images (WSI), or digital slides, can be viewed and navigated comparable to glass slides on a microscope, as digital files. Whole slide imaging has increased in adoption among pathologists, pathology departments, and scientists for clinical, educational, and research initiatives. Integration of digital pathology systems requires a coordinated effort with numerous stakeholders, not only within the pathology department, but across the entire enterprise. Each pathology department has distinct needs, use cases and blueprints, however the framework components and variables for successful clinical integration can be generalized across any organization seeking to undergo a digital transformation at any scale. This article will review those components and considerations for integrating digital pathology systems into clinical practice.

Validation of a digital pathology system including remote review during the COVID-19 pandemic.

Remote digital pathology allows healthcare systems to maintain pathology operations during public health emergencies. Existing Clinical Laboratory Improvement Amendments regulations require pathologists to electronically verify patient reports from a certified facility. During the 2019 pandemic of COVID-19 disease, caused by the SAR-CoV-2 virus, this requirement potentially exposes pathologists, their colleagues, and household members to the risk of becoming infected. Relaxation of government enforcement of this regulation allows pathologists to review and report pathology specimens from a remote, non-CLIA certified facility. The availability of digital pathology systems can facilitate remote microscopic diagnosis, although formal comprehensive (case-based) validation of remote digital diagnosis has not been reported. All glass slides representing routine clinical signout workload in surgical pathology subspecialties at Memorial Sloan Kettering Cancer Center were scanned on an Aperio GT450 at ×40 equivalent resolution (0.26 µm/pixel). Twelve pathologists from nine surgical pathology subspecialties remotely reviewed and reported complete pathology cases using a digital pathology system from a non-CLIA certified facility through a secure connection. Whole slide images were integrated to and launched within the laboratory information system to a custom vendor-agnostic, whole slide image viewer. Remote signouts utilized consumer-grade computers and monitors (monitor size, 13.3-42 in.; resolution, 1280 × 800-3840 × 2160 pixels) connecting to an institution clinical workstation via secure virtual private network. Pathologists subsequently reviewed all corresponding glass slides using a light microscope within the CLIA-certified department. Intraobserver concordance metrics included reporting elements of top-line diagnosis, margin status, lymphovascular and/or perineural invasion, pathology stage, and ancillary testing. The median whole slide image file size was 1.3 GB; scan time/slide averaged 90 s; and scanned tissue area averaged 612 mm2. Signout sessions included a total of 108 cases, comprised of 254 individual parts and 1196 slides. Major diagnostic equivalency was 100% between digital and glass slide diagnoses; and overall concordance was 98.8% (251/254). This study reports validation of primary diagnostic review and reporting of complete pathology cases from a remote site during a public health emergency. Our experience shows high (100%) intraobserver digital to glass slide major diagnostic concordance when reporting from a remote site. This randomized, prospective study successfully validated remote use of a digital pathology system including operational feasibility supporting remote review and reporting of pathology specimens, and evaluation of remote access performance and usability for remote signout.

Whole Slide Imaging: Technology and Applications.

Pathology has benefited from advanced innovation with novel technology to implement a digital solution. Whole slide imaging is a disruptive technology where glass slides are scanned to produce digital images. There have been significant advances in whole slide scanning hardware and software that have allowed for ready access of whole slide images. The digital images, or whole slide images, can be viewed comparable to glass slides in a microscope, as digital files. Whole slide imaging has increased in adoption among pathologists, pathology departments, and scientists for clinical, educational, and research initiatives. Worldwide usage of whole slide imaging has grown significantly. Pathology regulatory organizations (ie, College of American Pathologists) have put forth guidelines for clinical validation, and the US Food and Drug Administration have also approved whole slide imaging for primary diagnosis. This article will review the digital pathology ecosystem and discuss clinical and nonclinical applications of its use.

Digital pathology operations at a tertiary cancer center: Infrastructure requirements and operational cost.

Whole slide imaging is revolutionizing the field of pathology and is currently being used for clinical, educational, and research initiatives by an increasing number of institutions. Pathology departments have distinct needs for digital pathology systems, yet the cost of digital workflows is cited as a major barrier for widespread adoption by many organizations. Memorial Sloan Kettering Cancer Center (MSK) is an early adopter of whole slide imaging with incremental investments in resources that started more than 15 years ago. This experience and the large-scale scan operations led to the identification of required framework components of digital pathology operations. The cost of these components for the 2021 digital pathology operations at MSK were studied and calculated to enable an understanding of the operation and benchmark the accompanying costs. This paper describes the unique infrastructure cost and the costs associated with the digital pathology clinical operation use cases in a large, tertiary cancer center. These calculations can serve as a blueprint for other institutions to provide the necessary concepts and offer insights towards the financial requirements for digital pathology adoption by other institutions.

OncoTree: A Cancer Classification System for Precision Oncology.

PURPOSE: Cancer classification is foundational for patient care and oncology research. Systems such as International Classification of Diseases for Oncology (ICD-O), Systematized Nomenclature of Medicine Clinical Terms (SNOMED-CT), and National Cancer Institute Thesaurus (NCIt) provide large sets of cancer classification terminologies but they lack a dynamic modernized cancer classification platform that addresses the fast-evolving needs in clinical reporting of genomic sequencing results and associated oncology research. METHODS: To meet these needs, we have developed OncoTree, an open-source cancer classification system. It is maintained by a cross-institutional committee of oncologists, pathologists, scientists, and engineers, accessible via an open-source Web user interface and an application programming interface. RESULTS: OncoTree currently includes 868 tumor types across 32 organ sites. OncoTree has been adopted as the tumor classification system for American Association for Cancer Research (AACR) Project Genomics Evidence Neoplasia Information Exchange (GENIE), a large genomic and clinical data-sharing consortium, and for clinical molecular testing efforts at Memorial Sloan Kettering Cancer Center and Dana-Farber Cancer Institute. It is also used by precision oncology tools such as OncoKB and cBioPortal for Cancer Genomics. CONCLUSION: OncoTree is a dynamic and flexible community-driven cancer classification platform encompassing rare and common cancers that provides clinically relevant and appropriately granular cancer classification for clinical decision support systems and oncology research.

A Synoptic Electronic Order Set for Placental Pathology: A Framework Extensible to Nonneoplastic Pathology.

Accurate pathologic assessment in placental pathology is mostly dependent on a complete clinical history provided by a clinical team. However, often, the necessary clinical information is lacking, and electronic order sets (EOSs), if implemented correctly, create an opportunity for entering consistent and accurate clinical data. In this viewpoint piece, we describe a framework for synoptic EOS in placental pathology. We outline the necessary data and create optional clinical data that get entered as a dropdown menu of free text. While EOSs are the best way to approach and diagnose placenta and other nonneoplastic pathologic specimens, the barriers for implementation include paper requisitions and a cultural mindset resistance. The aspiration for our synoptic EOS is to become an effective tool for communication between proceduralists and pathologists for proper diagnosis of placental specimens. Through our EOS, the appropriate and complete clinical context is conveyed from the clinical teams to the pathologist. The pathologist can easily and rapidly extract the necessary information to render an accurate and precise diagnosis. The captured data likewise become a valuable research resource.

Mutational Profile Using Next-Generation Sequencing May Aid in the Diagnosis and Treatment of Urachal Adenocarcinoma.

Objectives. The rare urachal adenocarcinoma (UAC) of the bladder has striking morphologic and immunohistochemical overlap with colorectal adenocarcinoma (CAC) and bladder adenocarcinoma (BAC). To date, the mutational status in UAC and BAC has not been well investigated. Methods. We retrospectively evaluated 34 UACs (mucinous, n = 9; intestinal, n = 3; signet ring cell, n = 1; not otherwise specified, n = 21) and 4 BACs (n = 4). Next-generation sequencing analysis of 50 cancer "hotspot" gene mutations using the Ampliseq Cancer Hotspot Panel v2 was performed. Two UAC cases did not have adequate DNA quality with poor sequencing coverage and were excluded from the study. Results. RAS mutations were identified in 16 of 32 (50%) UACs (15 KRAS; 1 NRAS) and none of the BACs (0%). TP53 mutations were found in both UACs (18/32; 56%) and BACs (4/4; 100%). GNAS (n = 4), SMAD4 (n = 3), and BRAF (n = 1) mutations were only found in UACs. In contrast, APC (n = 2) mutations were only found in BACs. The mucinous subtype of UAC contained a SMAD4 mutation in 33% of cases (3/9), which was not identified in any other subtype (0/23; 0%) (P = .0169). The only BRAF mutation was identified in the single signet ring cell subtype of UAC. There were no other differences in the mutation profile when comparing histologic subtypes of UAC. Conclusions. In summary, UAC and BAC have overlapping but distinct mutation profiles and these differences may aid in separating these 2 entities. Next-generation sequencing to identify therapeutic targets or resistance markers may aid treatment decisions.

Validation of mitotic cell quantification via microscopy and multiple whole-slide scanners.

BACKGROUND: The establishment of whole-slide imaging (WSI) as a medical diagnostic device allows that pathologists may evaluate mitotic activity with this new technology. Furthermore, the image digitalization provides an opportunity to develop algorithms for automatic quantifications, ideally leading to improved reproducibility as compared to the naked eye examination by pathologists. In order to implement them effectively, accuracy of mitotic figure detection using WSI should be investigated. In this study, we aimed to measure pathologist performance in detecting mitotic figures (MFs) using multiple platforms (multiple scanners) and compare the results with those obtained using a brightfield microscope. METHODS: Four slides of canine oral melanoma were prepared and digitized using 4 WSI scanners. In these slides, 40 regions of interest (ROIs) were demarcated, and five observers identified the MFs using different viewing modes: microscopy and WSI. We evaluated the inter- and intra-observer agreements between modes with Cohen's Kappa and determined "true" MFs with a consensus panel. We then assessed the accuracy (agreement with truth) using the average of sensitivity and specificity. RESULTS: In the 40 ROIs, 155 candidate MFs were detected by five pathologists; 74 of them were determined to be true MFs. Inter- and intra-observer agreement was mostly "substantial" or greater (Kappa = 0.594-0.939). Accuracy was between 0.632 and 0.843 across all readers and modes. After averaging over readers for each modality, we found that mitosis detection accuracy for 3 of the 4 WSI scanners was significantly less than that of the microscope (p = 0.002, 0.012, and 0.001). CONCLUSIONS: This study is the first to compare WSIs and microscopy in detecting MFs at the level of individual cells. Our results suggest that WSI can be used for mitotic cell detection and offers similar reproducibility to the microscope, with slightly less accuracy.

Predominantly cystic clear cell renal cell carcinoma and multilocular cystic renal neoplasm of low malignant potential form a low-grade spectrum.

Multilocular cystic renal cell carcinoma has been recently excluded from clear cell renal cell carcinoma (CCRCC) category and re-designated as multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) due to its uniformly good outcomes. While strict distinction between MCRNLMP from predominantly cystic CCRCC (pc-CCRCC) is being emphasized, the significance of extensive true cystic component in CCRCC has not been investigated. Herein, we analyzed 57 MCRNLMP, 69 pc-CCRCC, and 46 non-cystic CCRCC. There were no statistically significant differences between the three subtypes in age, gender, and laterality. ISUP grades were 1 (73%) or 2 (27%) for MCRNLMP; for pc-CCRCC were 1 (31%), 2 (60%), and 3 (9%); and for non-cystic CCRCC were 1 (9%), 2 (52%), 3 (26%), and 4 (13%). MCRNLMP were either pT stage 1 (91%) or 2 (9%), pT stages for pc-CCRCC were 1 (92.5%), 2 (1.5%), and 3 (6%) and for non-cystic CCRCC were 1 (58.7%), 2 (6.5%), and 3 (34.8%). None of MCRNLMP patients developed recurrences or metastases, and only 1 contralateral kidney tumor and 1 metastasis developed in pc-CCRCC. In contrast, 19 patients with non-cystic CCRCC developed metastases (5-year PFS 58%, CI 38.3-73.5%), and 1 patient died of disease. Monosomy 3 was common in both MCRNLMP (3/3) and pc-CCRCC (6/7). This large series of MCRNLMP confirms its indolent behavior, shows that pc-CCRCC has significantly better prognosis than non-cystic CCRCC and may define the lower grade spectrum of CCRCC. We recommend that the presence and extent of CCRCC cystic component should be documented in the pathology report.

Successful Secure High-definition Streaming Telecytology for Remote Cytologic Evaluation.

BACKGROUND: The use of minimally invasive procedures to obtain material for diagnostic purposes has become more prevalent in recent years. As such, there is increased demand for immediate cytologic adequacy assessment of minimally invasive procedures. The array of different locations in which rapid on-site evaluation (ROSE) is expected requires an ever-increasing number of cytology personnel to provide support for adequacy assessment. In our study, we describe the implementation process of a telecytology (TC) system in a high case volume setting and evaluate the performance of this activity. METHODS: We performed retrospectively an analysis of all consecutive remote TC ROSE evaluations obtained for 15 months. The specimens were evaluated using a TC system. The ROSE adequacy assessment obtained at the time of the procedure was compared to the final cytopathologist-rendered adequacy assessment when all the material was available for review, including the alcohol-fixed preparations. RESULTS: A total of 8106 distinct cases were analyzed. TC-assisted preliminary adequacy assessment was highly concordant with the final cytopathologist-rendered adequacy assessment. Perfect concordance or accuracy was at 93.1% (7547/8106). The adequacy upgrade rate (inadequate specimen became adequate) was 6.8% (551/8106), and the initial adequacy downgrade (adequate specimen became inadequate) was <0.1% (8/8106). CONCLUSIONS: The TC outcome demonstrates high concordance between the initial adequacy assessment and final cytopathologist-rendered adequacy assessment. Adequacy upgrades were minor but, more importantly, our results demonstrate a minimal adequacy downgrade. The process implemented effectively eliminated the need for an attending pathologist to be physically present onsite during a biopsy procedure.

Robotic Telecytology for Remote Cytologic Evaluation without an On-site Cytotechnologist or Cytopathologist: A Tale of Implementation and Review of Constraints.

BACKGROUND: The first satellite center to offer interventional radiology procedures at Memorial Sloan Kettering Cancer Center opened in October 2014. Two of the procedures offered, fine needle aspirations and core biopsies, required rapid on-site cytologic evaluation of smears and biopsy touch imprints for cellular content and adequacy. The volume and frequency of such evaluations did not justify hiring on-site cytotechnologists, and therefore, a dynamic robotic telecytology (TC) solution was created. In this technical article, we present a detailed description of our implementation of robotic TC. METHODS: Pathology devised the remote robotic TC solution after acknowledging that it would not be cost effective to staff cytotechnologists on-site at the satellite location. Sakura VisionTek was selected as our robotic TC solution. In addition to configuration of the dynamic robotic TC solution, pathology realized integrating the technology solution into operations would require a multidisciplinary effort and reevaluation of existing staffing and workflows. RESULTS: Extensively described are the architectural framework and multidisciplinary process re-design, created to navigate the constraints of our technical, cultural, and organizational environment. Also reviewed are the benefits and challenges associated with available desktop sharing solutions, particularly accounting for information security concerns. CONCLUSIONS: Dynamic robotic TC is effective for immediate evaluations performed without on-site cytotechnology staff. Our goal is providing an extensive perspective of the implementation process, particularly technical, cultural, and operational constraints. Through this perspective, our template can serve as an extensible blueprint for other centers interested in implementing robotic TC without on-site cytotechnologists.

Robotic Telecytology for Remote Cytologic Evaluation without an On-site Cytotechnologist or Cytopathologist: An Active Quality Assessment and Experience of Over 400 Cases.

BACKGROUND: The first satellite center to offer interventional radiology procedures at Memorial Sloan Kettering Cancer Center opened in October 2014. Two of the procedures offered, fine needle aspirations and core biopsies, required a rapid on-site cytologic evaluation of smears and biopsy touch imprints for cellular content and adequacy. The volume and frequency of such evaluations did not justify hiring on-site cytotechnologists, and therefore, a dynamic robotic telecytology (TC) solution was created. In this article, we provide data on our experience with this active implementation. Sakura VisionTek was selected as our robotic TC solution. METHODS: A retrospective analysis of all TC evaluations from this satellite site was performed. Information was collected on demographics, lesion location, imaging modality; a comparison of TC-assisted adequacy with final adequacy was also conducted. RESULTS: An analysis of 439 cases was performed over a period of 23 months with perfect correlation in 92.7% (407/439) of the cases. An adequacy upgrade (inadequate specimen becomes adequate) in 6.6% (29/439) of the cases. An adequacy downgrade (adequate specimen becomes inadequate), is near zero at 0.7% (3/439) of the cases. CONCLUSIONS: Dynamic robotic TC is effective for immediate evaluations performed without on-site cytotechnology staff. The overall intent of this article is to present data and concordance rates as outcome metrics. Thus far, such outcome metrics have exceeded our expectations. Our TC implementation shows high, perfect concordance. Adequacy upgrades are minor but more relevant and impressive is a near zero adequacy downgrade. Our full implementation has been so successful that plans are in place for configurations at future satellite sites.

The different morphologies of urachal adenocarcinoma do not discriminate genomically by micro-RNA expression profiling.

Urachal adenocarcinoma has several morphologic presentations that include mucinous, enteric, signet ring cell, and not otherwise specified. Mixtures of these morphologies can occur, and percentage cut-offs are used for classification. The clinical significance of these morphologic types is currently unknown, and genetic analysis that could elucidate possible intertumoral differences has not been performed. In this study, we analyzed the micro-RNA expression profiles of 12 urachal adenocarcinomas classified using strict morphologic criteria (3 pure enteric, 3 pure mucinous, 2 signet ring cell [both 90% signet ring cell], 2 pure not otherwise specified, and 2 mixed cell types). Of 598 unique human micro-RNAs, 333 were expressed in more than 50% of the samples. Hierarchal clustering showed no distinct patterns in the genetic profiles of the morphologic types. However, there were individual micro-RNA differences when the different types were compared individually or grouped together, either by intracellular mucin production or by grouping enteric and signet ring cell together. In the later group, 13 messenger RNA species were differentially expressed (adjusted P value of ≤.05). However, these micro-RNA differences were small, suggesting more biologic similarity than differences among these entities. Thus, this study suggests that the different morphological subtypes may represent patterns of differentiation or a continuum of a single biological tumor type rather than several distinct types that arose from the urachal remnant epithelium. This finding, if further validated in larger studies, may have implications in future clinical therapeutic trials for urachal adenocarcinoma with regard to patient grouping and choice of therapy.

Urachal carcinomas of the nonglandular type: salient features and considerations in pathologic diagnosis.

The vast majority of malignant urachal epithelial tumors have a glandular morphology (ie, adenocarcinoma), to which our principal understanding of urachal carcinoma and its prevailing set of diagnostic criteria are largely ascribed. The 2004 World Health Organization classification of genitourinary tumors recognizes other rarer histologic types of urachal carcinomas such as urothelial, squamous cell, and other carcinomas. However, the clinicopathologic data for these nonglandular groups of urachal carcinomas are very limited, being detailed only in sporadic case reports. Some of the criteria recommended for pathologic confirmation of urachal carcinomas were formulated almost exclusively for urachal adenocarcinoma and may not be relevant or applicable for nonglandular tumors. Here, we present 7 examples of pure (5) and mixed predominant (2) nonglandular urachal carcinomas. Patients were 45 to 85 years of age (mean, 64.1) with a male predominance (male-to-female ratio=6:1). Six tumors were related to the bladder [dome (3) or dome/supravesical (3)] and 1 was entirely supravesical. Histologically, 5 were urothelial carcinomas, of pure or mixed histology, all were high grade and invasive, and 2 were small cell carcinomas. Two urothelial carcinomas had focal (<5%) glandular differentiation and signet ring cell change, and 1 had admixed focal malignant squamous cells and high-grade dedifferentiated components. Four of 5 urachal urothelial carcinomas exhibited solid and partly cavitary or luminal growth with papillary structures and a variable amount of necrosis within the cavity. The 2 small cell carcinomas were pure, had classic undifferentiated neuroendocrine histology, were situated at the bladder dome, and were partly cavitary filled with necrotic debris. Urachal remnant was identified in 6 tumors mainly with dysplastic transitional cells in the urachal canal or rudimentary nests and tubules. All 6 bladder-related urachal tumors exhibited reverse invasive front from the surface, including 2 tumors that ulcerated the bladder mucosa. One tumor had concomitant in situ and noninvasive high-grade papillary urothelial carcinomas in the main bladder lumen. Sheldon stages at presentation were IIIA (2), IVA (3), and IVB (2). Follow-up in all 7 cases (<1 to 60 mo; median, 12.5 mo) showed that 6 patients had died of disease, including the 2 patients with small cell carcinoma. In conclusion, nonglandular urachal carcinoma may occur with pure histology or admixed with high-grade dedifferentiated morphologies and a minor adenocarcinoma component. These tumors may arise as deep-seated bladder-related or completely supravesical tumors along the urachal tract and may exhibit reverse invasive spread toward the bladder surface. Cavitary or luminal growth may occur that could be attributed to the intraurachal neoplastic proliferation. Urachal urothelial carcinomas in particular may contain papillary structures within the tumor and urachal cavity. Concomitant primary urothelial carcinoma outside of the urachus and tumor extension to bladder mucosa may occur, which should not negate diagnosis of an urachal primary. Behavior appears poor, as most tumors present with higher stage.

Benefits of a combined approach to sampling of renal neoplasms as demonstrated in a series of 351 cases.

Percutaneous radiofrequency ablation is increasingly used for curative treatment of primary cancers of the kidney. We reviewed our experience of percutaneous sampling performed under computed tomographic guidance with fine needle aspiration biopsy (FNAB) and core biopsy (CB), and we report on the complementary roles of these 2 techniques in a series of 351 consecutive patients undergoing radiofrequency ablation for renal neoplasms. Both FNAB and CB were obtained in 290 cases, of which 156 patients (54%) were positive for neoplasm in both specimens, and 27 (9%) were negative for tumor in both specimens. In 58 (20%) patients, the FNABs were positive, but the CBs were negative, and the reverse occurred in 11 patients (4%). When suspicious interpretations by FNAB and CB are included as positives in the calculations, both their complementary nature and the relative higher diagnostic yield of FNAB persisted. In 25 cases with FNABs positive for neoplasm, the CB allowed a more specific tumor classification. The 19 cases of FNAB which were read as negative/benign had corresponding CBs that were also negative/benign in 13 cases; yet, 6 were diagnostic of renal cell carcinoma not otherwise specified (1 case), renal cell carcinoma clear cell/conventional (4 cases), and non-Hodgkin lymphoma (1 case). These and additional findings illustrate the complementary value of the combination of the 2 biopsy methods for a reliable pretherapy morphologic confirmation of specific renal neoplasms. FNAB has relatively greater sensitivity and utility for on-site evaluation, whereas CB provides an additional sample for more specific subclassification and additional studies.