Automated identification of glomeruli and synchronised review of special stains in renal biopsies by machine learning and slide registration: a cross-institutional study

AIMS

Machine learning in digital pathology can improve efficiency and accuracy via prescreening with automated feature identification. Studies using uniform histological material have shown promise. Generalised application requires validation on slides from multiple institutions. We used machine learning to identify glomeruli on renal biopsies and compared performance between single and multiple institutions.

METHODS AND RESULTS

Randomly selected, adequately sampled renal core biopsy cases (71) consisting of four stains each (haematoxylin and eosin, trichrome, silver, periodic acid Schiff) from three institutions were digitised at ×40. Glomeruli were manually annotated by three renal pathologists using a digital tool. Cases were divided into training/validation (n = 52) and evaluation (n = 19) cohorts. An algorithm was trained to develop three convolutional neural network (CNN) models which tested case cohorts intra- and inter-institutionally. Raw CNN search data from each of the four slides per case were merged into composite regions of interest containing putative glomeruli. The sensitivity and modified specificity of glomerulus detection (versus annotated truth) were calculated for each model/cohort. Intra-institutional (3) sensitivity ranged from 90 to 93%, with modified specificity from 86 to 98%. Interinstitutional (1) sensitivity was 77%, with modified specificity 97%. Combined intra- and inter-institutional (1) sensitivity was 86%, with modified specificity 92%.

CONCLUSIONS

Feature detection sensitivity degrades when training and test material originate from different sites. Training using a combined set of digital slides from three institutions improves performance. Differing histology methods probably account for algorithm performance contrasts. Our data highlight the need for diverse training sets for the development of generalisable machine learning histology algorithms.

Using Image Registration and Machine Learning to Develop a Workstation Tool for Rapid Analysis of Glomeruli in Medical Renal Biopsies

Background

Prescreening of biopsies has the potential to improve pathologists' workflow. Tools that identify features and display results in a visually thoughtful manner can enhance efficiency, accuracy, and reproducibility. Machine learning for detection of glomeruli ensures comprehensive assessment and registration of four different stains allows for simultaneous navigation and viewing.

Methods

Medical renal core biopsies (4 stains each) were digitized using a Leica SCN400 at ×40 and loaded into the Corista Quantum research platform. Glomeruli were manually annotated by pathologists. The tissue on the 4 stains was registered using a combination of keypoint- and intensity-based algorithms, and a 4-panel simultaneous viewing display was created. Using a training cohort, machine learning convolutional neural net (CNN) models were created to identify glomeruli in all stains, and merged into composite fields of views (FOVs). The sensitivity and specificity of glomerulus detection, and FOV area for each detection were calculated.

Results

Forty-one biopsies were used for training (28) and same-batch evaluation (6). Seven additional biopsies from a temporally different batch were also evaluated. A variant of AlexNet CNN, used for object recognition, showed the best result for the detection of glomeruli with same-batch and different-batch evaluation: Same-batch sensitivity 92%, "modified" specificity 89%, average FOV size represented 0.8% of the total slide area; different-batch sensitivity 90%, "modified" specificity 98% and average FOV size 1.6% of the total slide area.

Conclusions

Glomerulus detection in the best CNN model shows that machine learning algorithms may be accurate for this task. The added benefit of biopsy registration with simultaneous display and navigation allows reviewers to move from one machine-generated FOV to the next in all 4 stains. Together these features could increase both efficiency and accuracy in the review process.

Computational Cytology: Lessons Learned from Pap Test Computer-Assisted Screening

BACKGROUND

In the face of rapid technological advances in computational cytology including artificial intelligence (AI), optimization of its application to clinical practice would benefit from reflection on the lessons learned from the decades-long journey in the development of computer-assisted Pap test screening.

SUMMARY

The initial driving force for automated screening in cytology was the overwhelming number of Pap tests requiring manual screening, leading to workflow backlogs and incorrect diagnoses. Several companies invested resources to address these concerns utilizing different specimen processing techniques and imaging systems. However, not all companies were commercially prosperous. Successful implementation of this new technology required viable use cases, improved clinical outcomes, and an acceptable means of integration into the daily workflow of cytopathology laboratories. Several factors including supply and demand, Food and Drug Administration (FDA) oversight, reimbursement, overcoming learning curves and workflow changes associated with the adoption of new technology, and cytologist apprehension, played a significant role in either promoting or preventing the widespread adoption of automated screening technologies. Key Messages: Any change in health care, particularly those involving new technology that impacts clinical workflow, is bound to have its successes and failures. However, perseverance through learning curves, optimizing workflow processes, improvements in diagnostic accuracy, and regulatory and financial approval can facilitate widespread adoption of these technologies. Given their history with successfully implementing automated Pap test screening, cytologists are uniquely positioned to not only help with the development of AI technology for other areas of pathology, but also to guide how they are utilized, regulated, and managed.

The Bethesda System for Reporting Cervical Cytology: A Historical Perspective

The aims of The Bethesda System (TBS) were to provide effective communication from the laboratory to the clinical provider; facilitate cytologic-histologic correlation; facilitate research into the epidemiology, biology, and pathology of cervical disease; and provide reproducible and reliable data for national and international statistical analysis comparisons. Dr. Diane Solomon and colleagues' contribution to cervical cancer screening, diagnosis, and management began with the inception and dissemination of TBS for reporting cervical cytology in 1988, as detailed in the accompanying article [Solomon et al.: Acta Cytol 1989;33:567-574]. The significance of TBS for the further development and implementation of standardized terminology in pathology, and the research/management of cervical cancer have continued to evolve over the past three decades. TBS has always been a multidisciplinary effort and acknowledgement needs to be given to several stakeholders who, over the years, have contributed to its success. It has been our privilege and honor to have carried on the legacy of this seminal work, even as molecular methods are being closely integrated into cervical cancer screening, triage, and prevention.

Dr. Bibbo's Presidential Address on Automation in Cytology: Were Her Predictions Right, Wrong, or Somewhere in the Middle?

In 1983, Dr. Marluce Bibbo gave the Presidential Address at the Annual Meeting of the American Society of Cytology in Denver, CO, USA. The lecture was entitled "Analytic and Quantitative Cytology," a field in which Dr. Bibbo was intimately involved. In the presentation, she included a summary of 30 years of work already accomplished, the present state of the art, and musings about issues encountered, potential resolutions, progress that needed to be made, and her perception of how the field needed to evolve in order to become ultimately successful as a clinical service. This commentary looks back 34 years, with observations about Dr. Bibbo's predictions and how the field of cytology automation did actually evolve in the decades following her address. New challenges are identified and possible paths forward are discussed.

Bethesda Interobserver Reproducibility Study-2 (BIRST-2): Bethesda System 2014

INTRODUCTION

In concert with the 2014 update to the Bethesda System for Reporting Cervical Cytology, a Web-based image interobserver study was performed to evaluate concordance with the "expert panel" interpretation, as was done during the Bethesda 2001 update. The aim was to identify cytomorphologic features and Bethesda reporting categories that represent sources of poor interobserver agreement and see how the trends compared to the first Bethesda Interobserver Reproducibility Study (BIRST).

MATERIALS AND METHODS

Participants were recruited online through national and international cytopathology professional societies. Study participants evaluated 84 previously unpublished web images chosen from the third Bethesda Atlas image set, prior to the release of the atlas. These images spanned all reporting categories and included typical and borderline cytomorphology. Demographic information was collected on level of training, practice patterns, and experience of the participants. Participation was restricted to those correctly answering 2 basic cytopathology questions, ensuring minimal knowledge of gynecologic cytopathology.

RESULTS

A total of 1290 unique individuals attempted access to this Web-based study and 833 correctly answered the two qualifying questions. Of these, 518 respondents completed the survey. Participant origin included: 59% United States, 41% international; 48% cytotechnologists, 41% pathologists, 5% fellows, and 6% other. Practice types were: 39% academic institutions, 29% private hospitals, and 16% commercial laboratories. Overall, the mean participant agreement with the exact Bethesda panel interpretation was 62.8%. The best agreement was found for negative for intraepithelial lesion or malignancy (NILM; 74%) and low-grade squamous intraepithelial lesion (LSIL; 86%) categories. Squamous cell carcinoma (SCC) (63%), high-grade squamous intraepithelial lesion (HSIL; 60%), atypical squamous cells of undetermined significance (ASC-US; 62%) and atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H; 60%) showed slightly lower concordance with the panel interpretations. Cervical glandular lesions were more problematic (33%). Anal samples performed similarly to their gynecologic counterparts. There was similar diagnostic agreement across participant certifications and practice type (academic versus non-academic). Performance was higher for United States and other North America-based participants (P = 0.0104). This significance may be attributed to a language bias, as the survey was only offered in English.

CONCLUSIONS

Similar to the BIRST-1 study conducted in 2001, the most important factor for diagnostic agreement by cytotechnologists, pathologists, and trainees was the a priori difficulty of an image rather than participant training, certification, or experience. Participants showed better general diagnostic agreement with the expert panel interpretations of the material in BIRST-2 than in BIRST-1. Agreement was highest for Bethesda categories of NILM, LSIL, HSIL, and SCC. Concordance for even the borderline ASC-US and ASC-H categories exhibited remarkable improvement in the BIRST-2.

Digital pathology and its role in cytology education

Digital methods have the potential to greatly expand content availability, accessibility, and quality for pathology education. Use of this technology allows for anywhere/anytime interactions and delivery in a variety of methods to accommodate any learning style. This review introduces basic digital technology, its uses for education, and prospects for the future.

Fine-Needle Aspiration of Epithelial-Myoepithelial Carcinoma of the Parotid Gland With Prominent Adenoid Cystic Carcinoma-Like Cribriform Features: Avoiding a Diagnostic Pitfall

OBJECTIVES

Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland malignancy associated with an overall good prognosis. Fine-needle aspiration (FNA) typically shows a dual population of myoepithelial and ductal cells. Rarely, acellular matrix globules are present, raising a differential diagnosis of adenoid cystic carcinoma (AdCC), a more aggressive salivary gland malignancy associated with a poor long-term prognosis. We report an FNA case of EMC containing a predominant pattern of AdCC-like spherical globules.

METHODS

We compare features of an unusual case of EMC with those of cribriform AdCC to arrive at morphologic clues to the correct diagnosis.

RESULTS

Distinguishing features of EMC on FNA include (1) a prominent population of myoepithelial cells vs the predominance of basaloid cells in AdCC and (2) cohesive matrix globules with a peripheral rim of pale-staining basement membrane material compared with the dyscohesive matrix globules of AdCC. Immunochemical markers (S100, CD117, and MyB) are also useful.

CONCLUSIONS

Although EMC and AdCC can both contain spherical matrix globules, close evaluation of the cytomorphology of the globules and their relationship to surrounding cells provides a clue to distinguish the two neoplasms.

Bethesda 2014: improving on a paradigm shift

The third iteration of the Bethesda System terminology manual was recently published. This update included changes in the reporting of benign endometrial cells, and guidance for special adequacy situations and for cases in which low grade squamous intraepithelial lesions are accompanied by some cells suggesting that a high grade lesion might also be present. In addition, the manual was increased in size to include more illustrations with special studies and comparisons to histology, a greatly increased reference list, and a new chapter devoted to the modern practice of risk-based management. The third edition of the Bethesda manual is meant to serve as a primary reference for the practice of gynecologic cytology designed to provide a uniform system of reporting Worldwide for clinical, teaching, and research purposes.

Automated Extraction of Formalin-Fixed, Paraffin-Embedded Tissue for High-Risk Human Papillomavirus Testing of Head and Neck Squamous Cell Carcinomas Using the Roche Cobas 4800 System

CONTEXT

-Testing for high-risk human papillomavirus (HR-HPV) in head and neck squamous cell carcinomas (HNSCCs) is important for both prognostication and clinical management. Several testing platforms are available for HR-HPV; however, effective alternative automated approaches are needed.

OBJECTIVE

-To assess the performance of the automated Roche cobas 4800 HPV real-time polymerase chain reaction-based system on formalin-fixed, paraffin-embedded HNSCC specimens and compare results with standard methods of in situ hybridization (ISH) and p16 immunohistochemistry.

DESIGN

-Formalin-fixed, paraffin-embedded samples of HNSCC were collected from archival specimens in the Department of Pathology, Massachusetts General Hospital (Boston), and prepared using the automated system by deparaffinization and dehydration followed by tissue lysis. Samples were integrated into routine cervical cytology testing runs by cobas. Corresponding formalin-fixed, paraffin-embedded samples were evaluated for HR-HPV by ISH and p16 by immunohistochemistry. Discrepant cases were adjudicated by polymerase chain reaction.

RESULTS

-Sixty-two HNSCC samples were analyzed using the automated cobas system, ISH, and immunohistochemistry. Fifty-two percent (n = 32 of 62) of formalin-fixed, paraffin-embedded tumors were positive for HR-HPV by cobas. Eighty-eight percent (n = 28 of 32) of cases were the HPV 16 subtype and 12% (n = 4 of 32) were other HR-HPV subtypes. Corresponding testing with ISH was concordant in 92% (n = 57 of 62) of cases. Compared with the adjudication polymerase chain reaction standard, there were 3 false-positive cases by cobas.

CONCLUSIONS

-Concordance in HNSCC HR-HPV status between cobas and ISH was more than 90%. The cobas demonstrated a sensitivity of 100% and a specificity of 91% for detection of HR-HPV. Advantages favoring cobas include its automation, cost efficiency, objective results, and ease of performance.

Practical issues related to uterine pathology: in situ and invasive cervical glandular lesions and their benign mimics: emphasis on cytology-histology correlation and interpretive pitfalls

In situ and invasive neoplastic glandular lesions of the uterine have cytologic correlates that must be distinguished from a variety of benign and reactive conditions. Careful study of the cytologic features allows discrimination in the majority of cases; however, the designation of 'atypical glandular cells' is reserved for equivocal cases that cannot be readily resolved. In this article, the cytologic features of endocervical adenocarcinoma in situ and invasive endocervical adenocarcinoma will be presented, highlighting their correlation to the well-known histologic features. Variants of the usual type of endocervical neoplasms that have important clinical and differential diagnostic features, including mucinous adenocarcinoma and clear-cell carcinoma, will be discussed. There are a number of common cytologic mimics of endocervical neoplasms, including tubal metaplasia, directly sampled (abraded) endometrium, and high-grade squamous intraepithelial lesion involving endocervical glands. The cytologic features of these entities and their differentiation from endocervical neoplasia will be explored. Finally, the role of ancillary studies such as human papillomavirus testing in the management of glandular lesions of the cervix will be integrated into the discussion.

Automated 3-dimensional morphologic analysis of sputum specimens for lung cancer detection: Performance characteristics support use in lung cancer screening

BACKGROUND

The LuCED Lung Test comprises an automated 3-dimensional morphologic analysis of epithelial cells in sputum. For each cell, 594 morphology-based features are measured to drive algorithmic classifiers that quantitatively assess whether neoplastic cells are present. The current interim clinical study involves sputum samples from patients with known benign and malignant outcomes to assess the feasibility of LuCED as an adjunctive test after suspicious low-dose computed tomography (LDCT) results or as an independent screening test for lung cancer.

METHODS

Sputum samples were fixed, enriched for epithelial cells, and analyzed with a 3-dimensional cell scanner called Cell-CT. Candidate abnormal cells were identified by the classifiers for manual review. The sensitivity, specificity, and negative and positive predictive values were calculated for the detection of neoplastic cases.

RESULTS

A total of 91 sputum samples from patients with confirmed lung cancer (49 patients) and patients with no known malignancy (42 patients) were evaluated. After cytology review, sensitivity in the positive group was 91.8%, and specificity was 95.2%. Specificity was not 100% because there were 2 cases in which abnormal cells were identified by the Cell-CT that were confirmed as such at the time of manual cytology review. However, at the time of last follow-up, malignancy had not been detected in these 2 cases. Modeling in a population with a 1% prevalence of lung cancer, the positive and negative predictive values would be 95.4% and 99.9%, respectively.

CONCLUSIONS

LuCED testing is highly sensitive and specific for the detection of lung cancer and has potential value as an adjunctive test after suspicious LDCT findings or as a primary screening test in which LuCED-positive cases would be triaged to diagnostic CT. Further prospective studies currently are underway to evaluate its full usefulness.

Trends in Cervical Cytology Screening and Reporting Practices: Results From the College of American Pathologists 2011 PAP Education Supplemental Questionnaire

Context

The College of American Pathologists periodically surveys laboratories to determine changes in cytopathology practices. We report the results of a 2011 gynecologic cytology survey.

Objective

To provide a cross-sectional survey of gynecologic cytology practices in 2010.

Design

In 2011, a survey was sent to 1604 laboratories participating in the College of American Pathologists gynecologic cytology interlaboratory comparison education program and proficiency testing programs requesting data from 2010 on the following topics: terminology/reporting, cytotechnologist workload, quality assurance, reagents, and ancillary testing.

Results

Six hundred and twenty-five laboratories (39%) replied to the survey. The nonstandard use of “low-grade squamous intraepithelial lesion cannot exclude high-grade squamous intraepithelial lesion” is used by most laboratories to report the presence of low-grade squamous intraepithelial lesion with possibility of high-grade squamous intraepithelial lesion. Most laboratories also report the presence or absence of cells from the transformation zone. Most respondents do not limit cytotechnologist screening workload during the work shift. Only about one-third of laboratories (188 of 582; 32%) use image-assisted screening devices. Rapid prescreening as a quality assurance measure is used by only 3.5% (21 of 594) of the laboratories. When used for screening, most laboratories use the imager for retrospective review of slides to detect human locator and interpretive errors. Most laboratories receive both liquid-based cytology samples (mainly ThinPrep, Hologic, Marlborough, Massachusetts) and conventional Papanicolaou tests. Expiration dates of liquid-based cytology test vials are not usually recorded.

Conclusions

The field of gynecologic cytology is evolving rapidly. These survey results offer a snapshot of national gynecologic cytology practices in 2010.

Whole slide imaging for human epidermal growth factor receptor 2 immunohistochemistry interpretation: Accuracy, Precision, and reproducibility studies for digital manual and paired glass slide manual interpretation

Background:

The use of digital whole slide imaging for human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) could create improvements in workflow and performance, allowing for central archiving of specimens, distributed and remote interpretation, and the potential for additional computerized automation.

Procedures:

The accuracy, precision, and reproducibility of manual digital interpretation for HER2 IHC were determined by comparison to manual glass slide interpretation. Inter- and intra-pathologist reproducibility and precision between the glass slide and digital interpretations of HER2 IHC were determined in 5 studies using DAKO HercepTest-stained breast cancer slides with the Philips Digital Pathology System. In 2 inter-method studies, 3 pathologists interpreted glass and digital slides in sequence or in random order with a minimum of 7 days as a washout period. These studies also measured inter-observer reproducibility and precision. Another two studies measured intra-pathologist reproducibility on cases read 10 times by glass and digital methods. One additional study evaluated the effects of adding IHC control slides with each run, using 1 pathologist interpreting glass and digital slides randomized from the sets above along with appropriate controls for each slide in the set.

Results:

The overall results show that there is no statistical difference between the variance of performance when comparing glass and digital HER2 interpretations; and there were no effects noted when control tissues were evaluated in conjunction with the test slides.

Conclusions:

The results show that there is an equivalence of result when interpreting HER2 IHC slides in breast cancer by either glass slides or digital images. Digital interpretation can therefore be safely and effectively used for this purpose.

The Pap Test and Bethesda 2014. "The reports of my demise have been greatly exaggerated." (after a quotation from Mark Twain)

The history of 'The Bethesda System' for reporting cervical cytology goes back almost 3 decades. This terminology and the process that created it have had a profound impact on the practice of cervical cytology for laboratorians and clinicians alike. The Bethesda conferences and their ensuing output have also set the stage for standardization of terminology across multiple organ systems, including both cytology and histology, have initiated significant research in the biology and cost-effective management for human papillomavirus-associated anogenital lesions, and, finally, have fostered worldwide unification of clinical management for these lesions. Herein, we summarize the process and rationale by which updates were made to the terminology in 2014 and outline the contents of the new, third edition of the Bethesda atlas and corresponding website.

Computational pathology to discriminate benign from malignant intraductal proliferations of the breast

The categorization of intraductal proliferative lesions of the breast based on routine light microscopic examination of histopathologic sections is in many cases challenging, even for experienced pathologists. The development of computational tools to aid pathologists in the characterization of these lesions would have great diagnostic and clinical value. As a first step to address this issue, we evaluated the ability of computational image analysis to accurately classify DCIS and UDH and to stratify nuclear grade within DCIS. Using 116 breast biopsies diagnosed as DCIS or UDH from the Massachusetts General Hospital (MGH), we developed a computational method to extract 392 features corresponding to the mean and standard deviation in nuclear size and shape, intensity, and texture across 8 color channels. We used L1-regularized logistic regression to build classification models to discriminate DCIS from UDH. The top-performing model contained 22 active features and achieved an AUC of 0.95 in cross-validation on the MGH data-set. We applied this model to an external validation set of 51 breast biopsies diagnosed as DCIS or UDH from the Beth Israel Deaconess Medical Center, and the model achieved an AUC of 0.86. The top-performing model contained active features from all color-spaces and from the three classes of features (morphology, intensity, and texture), suggesting the value of each for prediction. We built models to stratify grade within DCIS and obtained strong performance for stratifying low nuclear grade vs. high nuclear grade DCIS (AUC = 0.98 in cross-validation) with only moderate performance for discriminating low nuclear grade vs. intermediate nuclear grade and intermediate nuclear grade vs. high nuclear grade DCIS (AUC = 0.83 and 0.69, respectively). These data show that computational pathology models can robustly discriminate benign from malignant intraductal proliferative lesions of the breast and may aid pathologists in the diagnosis and classification of these lesions.

Interinstitutional whole slide imaging teleconsultation service development: assessment using internal training and clinical consultation cases

CONTEXT

Assessment of accuracy and feasibility of whole slide imaging (WSI) for interinstitutional consultation in surgical pathology.

OBJECTIVES

To train technical and pathologist staff in WSI technology, establish and evaluate a WSI workflow using training cases and second-opinion consultations, and assess diagnostic accuracy.

DESIGN

First, WSI training and evaluation using selected subspecialty service cases were performed and compared with the clinical glass slide (GS) diagnosis. Second, WSI and GS diagnoses of consecutive, second-opinion consultation cases were compared. Discrepancies underwent adjudication to determine a reference diagnosis. Participant observations on WSI initiation to practice were gathered.

RESULTS

There were 130 cases evaluated, with 123 correlations (94.6%) and 6 minor (4.6%) and 1 major (0.8%) discrepancies. The 74 consultation cases interpreted had 52 correlations (70.3%), and 18 minor (24.3%) and 4 major (5.4%) discrepancies. The WSI and GS adjusted major discrepancy rates in second-opinion consultations were 2.7% (2 of 74) and 4.1% (3 of 74), respectively. Statistical analysis showed that WSI was not inferior to GS interpretation. Pathologists agreed the software was easy to use and the images were adequate, but more time was spent rendering WSI interpretations.

CONCLUSIONS

A significant learning curve was observed in the transition from the training set to clinical consultation cases associated both with WSI interpretation and adjustments to the digital analogs of routine GS workflow. Results from second-opinion consultations indicated that WSI interpretation was as accurate as GS interpretation among properly trained and experienced users. Overall, WSI-based practice appears feasible for second-opinion consultations.

Immunohistochemistry practices of cytopathology laboratories: a survey of participants in the College of American Pathologists Nongynecologic Cytopathology Education Program

CONTEXT

Immunohistochemistry (IHC) is important for cytology but poses special challenges because preanalytic conditions may differ from the conditions of IHC-positive controls.

OBJECTIVE

To broadly survey cytology laboratories to quantify preanalytic platforms for cytology IHC and identify problems with particular platforms or antigens. To discover how validation guidelines for HER2 testing have affected cytology.

DESIGN

A voluntary survey of cytology IHC practices was sent to 1899 cytology laboratories participating in the College of American Pathologists Nongynecologic Cytopathology Education Program in the fall of 2009.

RESULTS

A total of 818 laboratories (43%) responded to the survey by April 2010. Three hundred fourty-five of 791 respondents (44%) performed IHC on cytology specimens. Seventeen different fixation and processing platforms prior to antibody reaction were reported. A total of 59.2% of laboratories reported differences between the platforms for cytology specimens and positive controls, but most (155 of 184; 84%) did not alter antibody dilutions or antigen retrieval for cytology IHC. When asked to name 2 antibodies for which staining conditions differed between cytology and surgical samples, there were 18 responses listing 14 antibodies. A total of 30.6% of laboratories performing IHC offered HER2 testing before publication of the 2007 College of American Pathologists/American Society of Clinical Oncologists guidelines, compared with 33.6% afterward, with increased performance of testing by reference laboratories. Three laboratories validated a nonformalin HER2 platform.

CONCLUSIONS

The platforms for cytology IHC and positive controls differ for most laboratories, yet conditions are uncommonly adjusted for cytology specimens. Except for the unsuitability of air-dried smears for HER2 testing, the survey did not reveal evidence of systematic problems with any antibody or platform.

Performance of the Roche cobas 4800 high-risk human papillomavirus test in cytologic preparations of squamous cell carcinoma of the head and neck

BACKGROUND

Determining high-risk human papillomavirus (HR-HPV) status of head and neck squamous cell carcinoma (HNSCC) defines a tumor subset with important clinical implications. Cytologic sampling often provides the sentinel or sole diagnostic specimen. The authors assessed the performance characteristics for the Roche cobas 4800 HPV real-time polymerase chain reaction (PCR)-based system (cobas) on cytologic specimens of HNSCC compared with standard methods of in situ hybridization (ISH) for HR-HPV and immunohistochemistry (IHC) for p16 on formalin-fixed, paraffin-embedded (FFPE) tissue.

METHODS

Samples of HNSCC were collected by fine-needle aspiration and from surgical biopsies or resections, fixed, and processed with the cobas system. Available corresponding FFPE samples were synchronously evaluated for HR-HPV using ISH and IHC. Discrepant cases underwent additional PCR studies for adjudication.

RESULTS

Thirty-six samples from 33 patients were analyzed. Forty-two percent (n = 15) of tumors were positive for HR-HPV according to cobas. Corresponding histology with ISH (n = 30) was concordant in 91% of samples. Compared with the adjudication PCR standard, there were 3 false-positive cases according to cobas. Ninety-two percent (n = 12) of cases were the HPV16 subtype. The overall sensitivity for the cobas system was 100%, and the specificity was 86%.

CONCLUSIONS

Concordance in HNSCC HR-HPV status between cobas and ISH/IHC was > 90%, and cobas demonstrated a sensitivity of 100% and a specificity of 86%, broadening options for HR-HPV testing of fine-needle aspiration samples. Advantages for this system include subtyping of HR-HPV and the ability to discern HR-HPV status earlier in a patient's treatment course.

The Lower Anogenital Squamous Terminology Standardization project for HPV-associated lesions: background and consensus recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology

The terminology for human papillomavirus (HPV)-associated squamous lesions of the lower anogenital tract has a long history marked by disparate diagnostic terms derived from multiple specialties. It often does not reflect current knowledge of HPV biology and pathogenesis. A consensus process was convened to recommend terminology unified across lower anogenital sites. The goal was to create a histopathologic nomenclature system that reflects current knowledge of HPV biology, optimally uses available biomarkers, and facilitates clear communication across different medical specialties. The Lower Anogenital Squamous Terminology (LAST) project was co-sponsored by the College of American Pathologists (CAP) and the American Society for Colposcopy and Cervical Pathology (ASCCP) and included 5 working groups; three work groups performed comprehensive literature reviews and developed draft recommendations. Another work group provided the historical background and the fifth will continue to foster implementation of the LAST recommendations. After an open comment period, the draft recommendations were presented at a consensus conference attended by LAST work group members, advisors and representatives from 35 stakeholder organizations including professional societies and government agencies. Recommendations were finalized and voted upon at the consensus meeting. The final approved recommendations standardize biologically-relevant histopathologic terminology for HPV-associated squamous intraepithelial lesions and superficially invasive squamous carcinomas across all lower anogenital tract sites and detail appropriate use of specific biomarkers to clarify histologic interpretations and enhance diagnostic accuracy. A plan for disseminating and monitoring recommendation implementation in the practicing community was also developed. The implemented recommendations will facilitate communication between pathologists and their clinical colleagues and improve accuracy of histologic diagnosis with the ultimate goal of providing optimal patient care.

Effects on cervical cytology screening productivity associated with implementation of the BD FocalPoint™ Guided Screener Imaging System

OBJECTIVES

Automated screening will become important due to an aging workforce, declining numbers of new cytotechnologists, and the need for increased screening sensitivity in the vaccine era, where high-grade abnormalities will decline. This study documents workload in gynecologic cytology throughput before and after the implementation of the BD FocalPoint™ Guided Screener (GS) System.

STUDY DESIGN

We collected daily screening data from 3 time periods: the 12 months prior to GS implementation, the 6 months immediately after implementation, and the ensuing 7-18 months after implementation. Data was tabulated at the individual and total laboratory levels.

RESULTS

In the 6-month period immediately following implementation, productivity increased in 3 of 5 cytotechnologists, as compared to the figures 12 months before implementation. The laboratory increased productivity slightly (+2.4%), with individual changes ranging from -6.9 to +14.7%. In the 7- to 18-month 'mature' period after implementation, productivity increased in all 5 cytotechnologists with an average of +15.4%. Individual increases ranged from +6.1 to +26.9%.

CONCLUSIONS

Overall productivity increased in the period beyond 6 months, and this increase was eventually noted in all personnel. Increased productivity was associated with a short period of learning in which the magnitude of the effect was less than in the mature period.

The Lower Anogenital Squamous Terminology Standardization Project for HPV-Associated Lesions: background and consensus recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology

The terminology for human papillomavirus(HPV)–associated squamous lesions of the lower anogenital tract has a long history marked by disparate diagnostic terms derived from multiple specialties. It often does not reflect current knowledge of HPV biology and pathogenesis. A consensus process was convened to recommend terminology unified across lower anogenital sites. The goal was to create a histopathologic nomenclature system that reflects current knowledge of HPV biology, optimally uses available biomarkers, and facilitates clear communication across different medical specialties. The Lower Anogenital Squamous Terminology (LAST) Project was co-sponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology and included 5 working groups; 3 work groups performed comprehensive literature reviews and developed draft recommendations. Another work group provided the historical background and the fifth will continue to foster implementation of the LAST recommendations. After an open comment period, the draft recommendations were presented at a consensus conference attended by LAST work group members, advisors, and representatives from 35 stakeholder organizations including professional societies and government agencies. Recommendations were finalized and voted on at the consensus meeting. The final, approved recommendations standardize biologically relevant histopathologic terminology for HPV-associated squamous intraepithelial lesions and superficially invasive squamous carcinomas across all lower anogenital tract sites and detail the appropriate use of specific biomarkers to clarify histologic interpretations and enhance diagnostic accuracy. A plan for disseminating and monitoring recommendation implementation in the practicing community was also developed. The implemented recommendations will facilitate communication between pathologists and their clinical colleagues and improve accuracy of histologic diagnosis with the ultimate goal of providing optimal patient care.

Low-grade squamous intraepithelial lesion, cannot exclude high-grade squamous intraepithelial lesion: a category with an increased outcome of high-grade lesions: use as a quality assurance measure

"Low-grade squamous intraepithelial lesion (LSIL), cannot exclude high-grade squamous intraepithelial lesion" (LSIL-H) is an increasingly used, equivocal interpretive category in gynecologic cytology. In an effort to evaluate its potential usefulness as a measure of quality assurance, we studied patterns of use of the LSIL-H diagnosis compared with "LSIL" and "high-grade squamous intraepithelial lesion" (HSIL) with corresponding histologic outcomes for 10 cytopathologists in our practice. In our laboratory, while the overall rate of associated cervical intraepithelial neoplasia 2 or greater on histologic follow-up for LSIL-H was intermediate between that of LSIL and HSIL, the outcomes for individual cytopathologists varied widely. Monitoring this particular utilization-outcome data with periodic confidential feedback to individual cytopathologists offers an opportunity for practice improvement within a laboratory and serves as an additional measure of quality assurance. These data may be useful for establishing and/or realigning the diagnostic criteria for this equivocal cytologic interpretation endorsed by a pathology practice.

The Lower Anogenital Squamous Terminology Standardization Project for HPV-Associated Lesions: background and consensus recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology

The terminology for human papillomavirus (HPV)-associated squamous lesions of the lower anogenital tract has a long history marked by disparate diagnostic terms derived from multiple specialties. It often does not reflect current knowledge of HPV biology and pathogenesis. A consensus process was convened to recommend terminology unified across lower anogenital sites. The goal was to create a histopathologic nomenclature system that reflects current knowledge of HPV biology, optimally uses available biomarkers, and facilitates clear communication across different medical specialties. The Lower Anogenital Squamous Terminology (LAST) Project was cosponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology and included 5 working groups; 3 work groups performed comprehensive literature reviews and developed draft recommendations. Another work group provided the historical background and the fifth will continue to foster implementation of the LAST recommendations. After an open comment period, the draft recommendations were presented at a consensus conference attended by LAST work group members, advisors, and representatives from 35 stakeholder organizations including professional societies and government agencies. Recommendations were finalized and voted on at the consensus meeting. The final, approved recommendations standardize biologically relevant histopathologic terminology for HPV-associated squamous intraepithelial lesions and superficially invasive squamous carcinomas across all lower anogenital tract sites and detail the appropriate use of specific biomarkers to clarify histologic interpretations and enhance diagnostic accuracy. A plan for disseminating and monitoring recommendation implementation in the practicing community was also developed. The implemented recommendations will facilitate communication between pathologists and their clinical colleagues and improve accuracy of histologic diagnosis with the ultimate goal of providing optimal patient care.

American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer

An update to the American Cancer Society (ACS) guideline regarding screening for the early detection of cervical precancerous lesions and cancer is presented. The guidelines are based on a systematic evidence review, contributions from six working groups, and a recent symposium co-sponsored by the ACS, American Society for Colposcopy and Cervical Pathology (ASCCP), and American Society for Clinical Pathology (ASCP), which was attended by 25 organizations. The new screening recommendations address age-appropriate screening strategies, including the use of cytology and high-risk human papillomavirus (HPV) testing, follow-up (e.g., management of screen positives and screening interval for screen negatives) of women after screening, age at which to exit screening, future considerations regarding HPV testing alone as a primary screening approach, and screening strategies for women vaccinated against HPV16/18 infections.

American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer

An update to the American Cancer Society (ACS) guideline regarding screening for the early detection of cervical precancerous lesions and cancer is presented. The guidelines are based on a systematic evidence review, contributions from 6 working groups, and a recent symposium cosponsored by the ACS, the American Society for Colposcopy and Cervical Pathology, and the American Society for Clinical Pathology, which was attended by 25 organizations. The new screening recommendations address age-appropriate screening strategies, including the use of cytology and high-risk human papillomavirus (HPV) testing, follow-up (eg, the management of screen positives and screening intervals for screen negatives) of women after screening, the age at which to exit screening, future considerations regarding HPV testing alone as a primary screening approach, and screening strategies for women vaccinated against HPV16 and HPV18 infections.

American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer

An update to the American Cancer Society (ACS) guideline regarding screening for the early detection of cervical precancerous lesions and cancer is presented. The guidelines are based on a systematic evidence review, contributions from 6 working groups, and a recent symposium cosponsored by the ACS, the American Society for Colposcopy and Cervical Pathology, and the American Society for Clinical Pathology, which was attended by 25 organizations. The new screening recommendations address age-appropriate screening strategies, including the use of cytology and high-risk human papillomavirus (HPV) testing, follow-up (eg, the management of screen positives and screening intervals for screen negatives) of women after screening, the age at which to exit screening, future considerations regarding HPV testing alone as a primary screening approach, and screening strategies for women vaccinated against HPV16 and HPV18 infections.

Clinical fellowship training in pathology informatics: A program description

Background:

In 2007, our healthcare system established a clinical fellowship program in pathology informatics. In 2011, the program benchmarked its structure and operations against a 2009 white paper “Program requirements for fellowship education in the subspecialty of clinical informatics”, endorsed by the Board of the American Medical Informatics Association (AMIA) that described a proposal for a general clinical informatics fellowship program.

Methods:

A group of program faculty members and fellows compared each of the proposed requirements in the white paper with the fellowship program's written charter and operations. The majority of white paper proposals aligned closely with the rules and activities in our program and comparison was straightforward. In some proposals, however, differences in terminology, approach, and philosophy made comparison less direct, and in those cases, the thinking of the group was recorded. After the initial evaluation, the remainder of the faculty reviewed the results and any disagreements were resolved.

Results:

The most important finding of the study was how closely the white paper proposals for a general clinical informatics fellowship program aligned with the reality of our existing pathology informatics fellowship. The program charter and operations of the program were judged to be concordant with the great majority of specific white paper proposals. However, there were some areas of discrepancy and the reasons for the discrepancies are discussed in the manuscript.

Conclusions:

After the comparison, we conclude that the existing pathology informatics fellowship could easily meet all substantive proposals put forth in the 2009 clinical informatics program requirements white paper. There was also agreement on a number of philosophical issues, such as the advantages of multiple fellows, the need for core knowledge and skill sets, and the need to maintain clinical skills during informatics training. However, there were other issues, such as a requirement for a 2-year fellowship and for informatics fellowships to be done after primary board certification, that pathology should consider carefully as it moves toward a subspecialty status and board certification.

Prevalence of abnormalities influences cytologists' error rates in screening for cervical cancer

CONTEXT

Medical screening tasks are often difficult, visual searches with low target prevalence (low rates of disease). Under laboratory conditions, when targets are rare, nonexpert searchers show decreases in false-positive results and increases in false-negative results compared with results when targets are common. This prevalence effect is not due to vigilance failures or target unfamiliarity.

OBJECTIVE

To determine whether prevalence effects could be a source of elevated false-negative errors in medical experts.

DESIGN

We studied 2 groups of cytologists involved in cervical cancer screening (Boston, Massachusetts, and South Wales, UK). Cytologists evaluated photomicrographs of cells at low (2% or 5%) or higher (50%) rates of abnormality prevalence. Two versions of the experiment were performed. The Boston, Massachusetts, group made decisions of normal or abnormal findings using a 4-point rating scale. Additionally, the group from South Wales localized apparent abnormalities.

RESULTS

In both groups, there is evidence for prevalence effects. False-negative errors were 17% (higher prevalence), rising to 30% (low prevalence) in the Boston, Massachusetts, group. The error rate was 27% (higher prevalence), rising to 42% (low prevalence) in the South Wales group. (Comparisons between the 2 groups are not meaningful because the stimulus sets were different.)

CONCLUSIONS

These results provide the first evidence, to our knowledge, that experts are not immune to the effects of prevalence even with stimuli from their domain of expertise. Prevalence is a factor to consider in screening for disease by human observers and has significant implications for cytology-based cervical cancer screening in the post-human papillomavirus vaccine era, when prevalence rates of high-grade lesions in the population are expected to decline.

Cytologic features of focal papillary thyroid carcinoma arising within follicular adenoma: a masked cytomorphologic analysis of 17 cases

BACKGROUND/OBJECTIVE

Focal papillary thyroid carcinoma (PTC) arising within a follicular adenoma (PTCFA) represents a clinically significant, but rare, histopathologic subset of papillary carcinomas whose cytologic features have not been well described. This uncommon presentation of PTC may contribute to a subset of thyroid aspirates interpreted as 'atypia of undetermined significance/follicular lesion of undetermined significance' (AUS/FLUS).

STUDY DESIGN

Seventeen fine-needle aspiration biopsy (FNAB) cases diagnosed as 'PTCFA' on corresponding surgical excision were identified from the archival records of 2 large academic medical centers. A control group of 40 FNAB comprised of 20 follicular adenomas (FA) and 20 PTC was identified (based on the corresponding surgical pathology diagnosis) for comparison. All 57 FNAB were reviewed in a masked fashion and scored for a series of 31 cytomorphologic features. The intraclass correlation between diagnostic categories and overall agreement between cytopathologists was statistically evaluated.

RESULTS

Aspirates of PTCFA were originally diagnosed as 'negative' (n = 3), 'AUS/FLUS' (n = 7), 'suspicious for a follicular neoplasm' (n = 3), 'suspicious for malignancy' (n = 3), and 'malignant' (n = 1). On masked review, the most common cytomorphologic features of PTCFA were a nonmacrofollicular cytoarchitectural pattern (71%), medium-large cell size (74%), and micronucleoli (79%). Intranuclear pseudoinclusions and a papillary architecture were absent in 85 and 88% of the cases, respectively. Relative to the 2 control groups, the PTCFA cases demonstrated overlapping features between FA and PTC for the majority of the 31 examined cytomorphologic features.

CONCLUSION

PTCFA represent a rare subset of PTC that is difficult to recognize as PTC by FNAB. Most cases exhibit overlapping features between a benign thyroid nodule and conventional PTC, and they are often interpreted as 'AUS/FLUS'.

Gynecologic Cytology Proficiency Testing Failures: What Have We Learned?: Observations From the College of American Pathologists Gynecologic Cytology Proficiency Testing Program

Context.—In 2006, the first gynecologic cytology proficiency tests were offered by the College of American Pathologists. Four years of data are now available using field-validated slides, including conventional and liquid-based Papanicolaou tests.

Objective.—To characterize the pattern of error types that resulted in initial proficiency-test failure for cytotechnologists, primary screening pathologists, and secondary pathologists (those whose slides are prescreened by cytotechnologists).

Design.—The results of 37 029 initial College of American Pathologists Papanicolaou proficiency tests were reviewed from 4 slide-set modules: conventional, ThinPrep, SurePath, or a module containing all 3 slide types.

Results.—During this 4-year period, cytotechnologists were least likely to fail the initial test (3.4%; 614 of 18 264), followed by secondary pathologists (ie, those reviewing slides already screened by a cytotechnologist) with a failure rate of 4.2% (728 of 17 346), and primary pathologists (ie, those screening their own slides) having the highest level of failure (13.7%; 194 of 1419). Failure rates have fallen for all 3 groups over time. Pathologists are graded more stringently on proficiency tests, and more primary pathologists would have passed if they had been graded as cytotechnologists. There were no significant differences among performances using different types of slide sets. False-positive errors were common for both primary (63.9%; 124 of 194 errors) and secondary (55.6%; 405 of 728 errors) pathologists, whereas automatic failures were most common for cytotechnologists (75.7%; 465 of 614 errors).

Conclusions.—The failure rate is decreasing for all participants. The failures for primary pathologist screeners are due to false-positive responses. Primary screening cytotechnologists and secondary pathologists have automatic failures more often than do primary screening pathologists.

Review of the current state of whole slide imaging in pathology

Whole slide imaging (WSI), or “virtual” microscopy, involves the scanning (digitization) of glass slides to produce “digital slides”. WSI has been advocated for diagnostic, educational and research purposes. When used for remote frozen section diagnosis, WSI requires a thorough implementation period coupled with trained support personnel. Adoption of WSI for rendering pathologic diagnoses on a routine basis has been shown to be successful in only a few “niche” applications. Wider adoption will most likely require full integration with the laboratory information system, continuous automated scanning, high-bandwidth connectivity, massive storage capacity, and more intuitive user interfaces. Nevertheless, WSI has been reported to enhance specific pathology practices, such as scanning slides received in consultation or of legal cases, of slides to be used for patient care conferences, for quality assurance purposes, to retain records of slides to be sent out or destroyed by ancillary testing, and for performing digital image analysis. In addition to technical issues, regulatory and validation requirements related to WSI have yet to be adequately addressed. Although limited validation studies have been published using WSI there are currently no standard guidelines for validating WSI for diagnostic use in the clinical laboratory. This review addresses the current status of WSI in pathology related to regulation and validation, the provision of remote and routine pathologic diagnoses, educational uses, implementation issues, and the cost-benefit analysis of adopting WSI in routine clinical practice.