An International Consensus to Standardize Integration of Histopathology in Ulcerative Colitis Clinical Trials.

BACKGROUND & AIMS: Histopathology is an emerging treatment target in ulcerative colitis (UC) clinical trials. Our aim was to provide guidance on standardizing biopsy collection protocols, identifying optimal evaluative indices, and defining thresholds for histologic response and remission after treatment. METHODS: An international, interdisciplinary expert panel of 19 gastroenterologists and gastrointestinal pathologists was assembled. A modified RAND/University of California, Los Angeles appropriateness methodology was used to address relevant issues. A total of 138 statements were derived from a systematic review of the literature and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate using a 9-point scale. Survey results were reviewed and discussed before a second round of voting. RESULTS: Histologic measurements collected using a uniform biopsy strategy are important for assessing disease activity and determining therapeutic efficacy in UC clinical trials. Multiple biopsy strategies were deemed acceptable, including segmental biopsies collected according to the endoscopic appearance. Biopsies should be scored for architectural change, lamina propria chronic inflammation, basal plasmacytosis, lamina propria and epithelial neutrophils, epithelial damage, and erosions/ulcerations. The Geboes score, Robarts Histopathology Index, and Nancy Index were considered appropriate for assessing histologic activity; use of the modified Riley score and Harpaz Index were uncertain. Histologic activity at baseline should be required for enrollment, recognizing this carries operational implications. Achievement of histologic improvement or remission was considered an appropriate and realistic therapeutic target. Current histologic indices require validation for pediatric populations. CONCLUSIONS: These recommendations provide a framework for standardized implementation of histopathology in UC trials. Additional work is required to address operational considerations and areas of uncertainty.

Appropriate use criteria for ancillary diagnostic testing in dermatopathology: New recommendations for 11 tests and 220 clinical scenarios from the American Society of Dermatopathology Appropriate Use Criteria Committee.

BACKGROUND: Appropriate use criteria (AUC) provide patient-centered physician guidance in test selection. An initial set of AUC was reported by the American Society of Dermatopathology (ASDP) in 2018. AUC reflect evidence collected at single timepoints and may be affected by evolving evidence and experience. The objective of this study was to update and expand AUC for selected tests. METHODS: RAND/UCLA (RAND Corporation [Santa Monica, CA]/University of California Los Angeles) methodology used includes the following: (a) literature review; (b) review of previously rated tests and previously employed clinical scenarios; (c) selection of previously rated tests for new ratings; (d) development of new clinical scenarios; (e) selection of additional tests; (f) three rating rounds with feedback and group discussion after rounds 1 and 2. RESULTS: For 220 clinical scenarios comprising lymphoproliferative (light chain clonality), melanocytic (comparative genomic hybridization, fluorescence in situ hybridization, reverse transcription polymerase chain reaction, telomerase reverse transcriptase promoter), vascular disorders (MYC), and inflammatory dermatoses (periodic acid-Schiff, Gömöri methenamine silver), consensus by panel raters was reached in 172 of 220 (78%) scenarios, with 103 of 148 (70%) rated "usually appropriate" or "rarely appropriate" and 45 of 148 (30%), "appropriateness uncertain." LIMITATIONS: The study design only measures appropriateness. Cost, availability, test comparison, and additional clinical considerations are not measured. The possibility that the findings of this study may be influenced by the inherent biases of the dermatopathologists involved in the study cannot be excluded. CONCLUSIONS: AUC are reported for selected diagnostic tests in clinical scenarios that occur in dermatopathology practice. Adhering to AUC may reduce inappropriate test utilization and improve healthcare delivery.

Accuracy of Pathology Reports on Neck Dissection Specimens: A Retrospective Case Series Study.

BACKGROUND: Accuracy of the number and location of pathological lymph nodes (LNs) in the pathology report of a neck dissection (ND) is of vital importance. OBJECTIVES: To quantify the error rate in reporting the location and number of pathologic LNs in ND specimens. METHODS: All patients who had undergone a formal ND that included at least neck level 1 for a clinical N1 disease between January 2010 and December 2017 were included in the study. The error rate of the pathology reports was determined by various means: comparing preoperative imaging and pathological report, reporting a disproportionate LN distribution between the different neck levels, and determining an erroneous location of the submandibular gland (SMG) in the pathology report. Since the SMG must be anatomically located in neck level 1, any mistake in reporting it was considered a categorical error. RESULTS: A total of 227 NDs met the inclusion criteria and were included in the study. The study included 128 patients who had undergone a dissection at levels 1-3, 68 at levels 1-4, and 31 at levels 1-5. The best Kappa score for correlation between preoperative imaging and final pathology was 0.50. There were nine cases (3.9%) of a disproportionate LN distribution in the various levels. The SMG was inaccurately reported outside neck level 1 in 17 cases (7.5%). CONCLUSIONS: At least 7.5% of ND reports were inaccurate in this investigation. The treating physician should be alert to red flags in the pathological report.

Dataset for the reporting of carcinoma of the exocrine pancreas: recommendations from the International Collaboration on Cancer Reporting (ICCR).

AIMS: Current guidelines for pathology reporting on pancreatic cancer differ in certain aspects, resulting in divergent reporting practices and a lack of comparability of data. Here, we report on a new international dataset for pathology reporting on resection specimens with cancer of the exocrine pancreas (ductal adenocarcinoma and acinar cell carcinoma). The dataset was produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), which is a global alliance of major (inter)national pathology and cancer organisations. METHODS AND RESULTS: According to the ICCR's rigorous process for dataset development, an international expert panel consisting of pancreatic pathologists, a pancreatic surgeon and an oncologist produced a set of core and non-core data items based on a critical review and discussion of current evidence. Commentary was provided for each data item to explain the rationale for selecting it as a core or non-core element and its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. Following international public consultation, the document was finalised and ratified, and the dataset, which includes a synoptic reporting guide, was published on the ICCR website. CONCLUSIONS: This first international dataset for cancer of the exocrine pancreas is intended to promote high-quality, standardised pathology reporting. Its widespread adoption will improve the consistency of reporting, facilitate multidisciplinary communication, and enhance the comparability of data, all of which will help to improve the management of pancreatic cancer patients.

Digital Pathology During the COVID-19 Outbreak in Italy: Survey Study.

BACKGROUND: Transition to digital pathology usually takes months or years to be completed. We were familiarizing ourselves with digital pathology solutions at the time when the COVID-19 outbreak forced us to embark on an abrupt transition to digital pathology. OBJECTIVE: The aim of this study was to quantitatively describe how the abrupt transition to digital pathology might affect the quality of diagnoses, model possible causes by probabilistic modeling, and qualitatively gauge the perception of this abrupt transition. METHODS: A total of 17 pathologists and residents participated in this study; these participants reviewed 25 additional test cases from the archives and completed a final psychologic survey. For each case, participants performed several different diagnostic tasks, and their results were recorded and compared with the original diagnoses performed using the gold standard method (ie, conventional microscopy). We performed Bayesian data analysis with probabilistic modeling. RESULTS: The overall analysis, comprising 1345 different items, resulted in a 9% (117/1345) error rate in using digital slides. The task of differentiating a neoplastic process from a nonneoplastic one accounted for an error rate of 10.7% (42/392), whereas the distinction of a malignant process from a benign one accounted for an error rate of 4.2% (11/258). Apart from residents, senior pathologists generated most discrepancies (7.9%, 13/164). Our model showed that these differences among career levels persisted even after adjusting for other factors. CONCLUSIONS: Our findings are in line with previous findings, emphasizing that the duration of transition (ie, lengthy or abrupt) might not influence the diagnostic performance. Moreover, our findings highlight that senior pathologists may be limited by a digital gap, which may negatively affect their performance with digital pathology. These results can guide the process of digital transition in the field of pathology.

Classification and reporting guidelines for the pathology diagnosis of placenta accreta spectrum (PAS) disorders: recommendations from an expert panel.

The terminology and diagnostic criteria presently used by pathologists to report invasive placentation is inconsistent and does not reflect current knowledge of the pathogenesis of the disease or the needs of the clinical care team. A consensus panel was convened to recommend terminology and reporting elements unified across the spectrum of PAS specimens (i.e., delivered placenta, total or partial hysterectomy with or without extrauterine tissues, curetting for retained products of conception). The proposed nomenclature under the umbrella diagnosis of placenta accreta spectrum (PAS) replaces the traditional categorical terminology (placenta accreta, increta, percreta) with a descriptive grading system that parallels the guidelines endorsed by the International Federation of Gynaecology and Obstetrics (FIGO). In addition, the nomenclature for hysterectomy specimens is separated from that for delivered placentas. The goal for each element in the system of nomenclature was to provide diagnostic criteria and guidelines for expected use in clinical practice.

Interobserver variation in the classification of thymic lesions including biopsies and resection specimens in an international digital microscopy panel.

AIMS: Thymic tumours are rare in routine pathology practice. Although the World Health Organization (WHO) classification describes a number of well-defined categories, the classification remains challenging. The aim of this study was to investigate the reproducibility of the WHO classification among a large group of international pathologists with expertise in thymic pathology and by using whole slide imaging to facilitate rapid diagnostic turnover. METHODS AND RESULTS: Three hundred and five tumours, consisting of 90 biopsies and 215 resection specimens, were reviewed with a panel-based virtual microscopy approach by a group of 13 pathologists with expertise in thymic tumours over a period of 6 years. The specimens were classified according to the WHO 2015 classification. The data were subjected to statistical analysis, and interobserver concordance (Fleiss kappa) was calculated. All cases were diagnosed within a time frame of 2 weeks. The overall level of agreement was substantial (κ = 0.6762), and differed slightly between resection specimens (κ = 0.7281) and biopsies (κ = 0.5955). When analysis was limited to thymomas only, and they were grouped according to the European Society for Medical Oncology Clinical Practice Guidelines into B2, B3 versus A, AB, B1 and B3 versus A, AB, B1, B2, the level of agreement decreased slightly (κ = 0.5506 and κ = 0.4929, respectively). Difficulties arose in distinguishing thymoma from thymic carcinoma. Within the thymoma subgroup, difficulties in distinction were seen within the B group. CONCLUSIONS: Agreement in diagnosing thymic lesions is substantial when they are assessed by pathologists with experience of these rare tumours. Digital pathology decreases the turnaround time and facilitates access to what is essentially a multinational resource. This platform provides a template for dealing with rare tumours for which expertise is sparse.

Autopsy Services and Emergency Preparedness of a Tertiary Academic Hospital Mortuary for the COVID-19 Public Health Emergency: The Yale Plan.

Pathology Autopsy and Mortuary Services have been front and center in the severe acute respiratory syndrome coronavirus 2 (SARS-Co-V-2) pandemic. The sheer number of fatalities from the pandemic have been unlike any other in recent memory and needed the rapid creation of new protocols and paradigms to manage the situation. This required rapidly escalating mortuary capacity to manage the increased fatalities from the pandemic with the establishment of lines of communication and networking with governmental entities, institution of new policies for patient flow, and implementation of worker infection control and well-being plans. Autopsies also assumed a crucial role, both to provide insight into the pathomechanisms of a novel disease and to allow tissue retrieval necessary to power research directed towards finding a vaccine. We here outline the plan adopted by the Yale Autopsy and Mortuary Services, in alignment with the institutional mission of high-quality patient care, education, research and health care worker safety and well-being, as the Corona Virus Disease of 2019 (COVID-19) pandemic surged in Connecticut. In the early response phase, ensuring sufficient mortuary capacity necessarily took center stage. As we enter the recovery and plateau phase of the pandemic, setting up a process for a rapid and safe autopsy, that will meet educational and research needs while ensuring the safety of our workforce is being implemented.

The effect of entrustable professional activities on pathology resident confidence in blood banking/transfusion medicine.

BACKGROUND: The Accreditation Council for Graduate Medical Education requires milestone reporting of the Six General Core Competencies. Additionally, Graduate Medical Education (GME) is transitioning to adopt competency-based education methodologies including entrustable professional activities (EPAs) for objective, observable, and measurable milestone progression. The College of American Pathologists published 19 EPAs, including one for transfusion-related adverse events. This survey study includes developing EPAs for transfusion reaction evaluation and assessing residents before and after implementing these EPAs. STUDY DESIGN AND METHODS: Three transfusion reaction EPAs were developed and implemented in July 2018 for the Postgraduate Year (PGY) 2 pathology residents. An online, anonymous survey was sent to all 21 pathology trainees before and one year after EPA implementation. In July 2018 and August 2019, each survey included the same six multiple-choice, single-response, confidence questions, with a rating scale of extremely, very, slightly, or not at all confident. This study was approved by the hospital's Institutional Review Board for Health Sciences Research and GME Committee. RESULTS: Analysis was performed on PGY2-4 residents. In 2018, 13 of 20 participants were analyzed. In 2019, 15 of 19 participants were analyzed. Number and percentage of responses were reported. The results showed an increase in trainee confidence, with the greatest improvement among the first class to use the EPAs. CONCLUSION: EPAs provide an effective framework for objective and measurable progression of trainees. One year after the implementation of transfusion reaction EPAs at our site, the trainees showed enhanced confidence levels in handling Blood Bank and Transfusion Medicine Services coverage.

Scientific and Regulatory Policy Committee Points to Consider*: Approaches to the Conduct and Interpretation of Vaccine Safety Studies for Clinical and Anatomic Pathologists.

The design and execution of toxicology studies supporting vaccine development have some unique considerations relative to those supporting traditional small molecules and biologics. A working group of the Society of Toxicologic Pathology Scientific and Regulatory Policy Committee conducted a review of the scientific, technical, and regulatory considerations for veterinary pathologists and toxicologists related to the design and evaluation of regulatory toxicology studies supporting vaccine clinical trials. Much of the information in this document focuses on the development of prophylactic vaccines for infectious agents. Many of these considerations also apply to therapeutic vaccine development (such as vaccines directed against cancer epitopes); important differences will be identified in various sections as appropriate. The topics addressed in this Points to Consider article include regulatory guidelines for nonclinical vaccine studies, study design (including species selection), technical considerations in dosing and injection site collection, study end point evaluation, and data interpretation. The intent of this publication is to share learnings related to nonclinical studies to support vaccine development to help others as they move into this therapeutic area. [Box: see text].

Reproducibility of Grading in Chronic Intervillositis of Unknown Etiology.

Chronic intervillositis of unknown etiology (CIUE) is a rare placental inflammatory process associated with pregnancy loss and recurrence. We conducted a quality assurance study to assess the diagnostic accuracy and reproducibility of CIUE grading at our institution. Hematoxylin and eosin-stained slides from 20 CIUE cases (31 slides) were reviewed by 7 perinatal pathologists in 2 sequential rounds. Reviewers were instructed to use the diagnostic criteria they were presently following for CIUE and to grade each slide according to the Rota scheme. In the first round, 20 slides were assessed. The diagnostic accuracy was 94%, the average percent agreement of Rota grade was 79%, and the Fleiss' kappa value for interobserver variability was 0.54. The results were reviewed by all pathologists with diagnostic and grading criteria agreed upon prior to the second round. In round 2, the remaining 11 slides were assessed. Diagnostic accuracy was 83%, the average percent agreement on Rota grade was 70%, and the Fleiss' kappa value for interobserver variability was 0.36. Overall, diagnostic accuracy was high and agreement on Rota grade was moderate. Group review did not appear to improve accuracy. Simplifying CIUE grading to a low-grade/high-grade scheme (<50% or ≥50%) might improve grading reproducibility.

Quality assurance in neuropathology: Experiences from the round robin trials on IDH mutation and MGMT promoter methylation testing launched by the Quality Assurance Initiative Pathology (QuIP) in 2018 and 2019.

We here report on the first neuropathological round robin trials initiated by the Quality Assurance Initiative Pathology (QuIP) in Germany in the years 2018 and 2019. Testing services as external laboratory controls were offered for IDH1-R132H immunohistochemistry in 2018 followed by a molecular trial for IDH1 and IDH2 mutations in 2019 including the rare mutational variants. Also in 2019, a trial on MGMT promoter methylation testing was offered. On a national scale, trial offers were well received with around 40 participating institutions. The international announcement of the molecular IDH1/IDH2 mutational trial achieved only moderate European outspread. Success rates in all three trials were excellent (IDH1-R132H immunohistochemistry 2018: 94%, 18 out of 20 possible points required; IDH1/IDH2 mutational status 2019: 100%, 19 out of 20 possible points required; MGMT promoter methylation 2019: 94%, 19 out of 20 possible points required) indicating that quality standards are high in the broad majority of the institutions. Trial participation also involved filling in a questionnaire asking for background information on local testing procedures. We here present a first assessment of the information collected providing unique insights in the landscape of molecular testing in neuropathology. Derived from this information we identify future challenges and provide an outlook on the development of quality assurance in the field of neuropathology.

Prognosis in pathology: Are we "prognosticating" or only establishing correlations between independent variables and survival? A study with various analytics cautions about the overinterpretation of statistical results.

Survival data from 225 patients with resected pulmonary typical carcinoids were analyzed with Kaplan-Meier statistics (K-M) and "deep learning" methods to illustrate the difference between establishing "correlations" and "prognostications". Cases were stratified into G1 and G2 classes using a ≤5% Ki-67% cut-point. Overall survival, number of patients at risk and 95% confidence intervals (CI) were estimated for the two classes. Seven neural network models (NN) were developed with GMDH Shell 3.8.2 and Statgraphics Centurion 18.1 software, using variable prior probabilities and different numbers of training vs testing cases. The NNs used age, sex, and pTNM, G1 and G2 as input neurons and "alive" and "dead" as output neurons. Areas under the curve (AUC) and other performance measures were evaluated for all models. Log-rank test showed a significant difference in overall survival between G1 and G2 (p < 0.001). However, 95% CI estimates showed considerable variability in survival at different time intervals. Including the number of patients at risk at different time intervals showed that most G2 patients had been censored by 100 weeks. The NN models provided variable "prognostications", with AUC ranging from 0.5 to 1 and variability in the sensitivity, specificity, and other performance measures. The results illustrate the limitations of survival statistics and NNs in predicting the prognosis of individual patients. The need for pathologists not to overinterpret the finding of significant correlations as "prognostic" or "predictive" for individual patients is discussed.

An investigation of European pathologists' approach to diagnose microscopic colitis.

Microscopic colitis (MC) comprising lymphocytic colitis (LC), collagenous colitis (CC) and the incomplete forms of microscopic colitis (MCi) are frequent causes of chronic watery diarrhea. The diagnosis is based on specific histological features in colonic biopsies. Especially regarding MCi, the histological features may be subtle. The PRO-MC collaboration was established in 2016 with the aims to systematically describe the disease course and to validate the diagnostic criteria of MC. In the present study, we analysed pathologists' initial approach to diagnose MC. Five pathologists with expertise in gastro-intestinal pathology reviewed the first 10 cases enrolled in the PRO-MC registry in six of the participating centres. Despite considerable differences in strategies in biopsy sampling, in choice of stains and in minimum number of biopsies and segments required for diagnosing MC, inter-observer agreement between the participating centres and expert pathologists as well as among the latter was substantial. Disagreed cases most often related to difficulties in distinguishing between MC subgroups. We recommend that pathologists as well as clinicians reach consensus in their diagnostic approach to MC, which is a prerequisite to compare MC cohorts internationally and to facilitate clinical MC trials and follow-up studies.

Reproducibility of visual estimation of lung adenocarcinoma subtype proportions.

In 2011, a new classification of lung adenocarcinoma was published. Since then there have been multiple studies regarding observer variability in predominant subtype determination, with levels of agreement generally in the weak to moderate range. In the 2011 and subsequent WHO 2015 classification, a recommendation was also made to visually assess and record the percentage of each subtype in 5% increments. The present study was initiated to determine the reproducibility of such gestalt assessments and to compare these data to a formal morphometric assessment. Five experienced pathologists reviewed multiple single images of 25 adenocarcinomas, taken at 2× and 10×, and estimated the percentage of lepidic, acinar, papillary, micropapillary, and solid components in 5% increments. After 2 months all the pathologists again reviewed the same images presented to them in a different order. We found that there was poor reproducibility within observers at 2× power using a 5% evaluation, but that this improved using 10% or 25% cutoffs. Use of 10× magnification allowed weak to moderate reproducibility at 5% increments, and this was again improved using 10% or 25% cutoffs. Correlation with morphometric assessment was poor except for the papillary and micropapillary subtypes. Differences among pathologists were generally low except for the acinar and, to a lesser degree, lepidic subtypes, which showed a wide spread of data. When estimating tumor subtype proportions, use of a 10× objective, and utilization of 10% or preferably 25% cutoffs provides a greater degree of consistency than a 5% cutoff.

Datasets for the reporting of neoplasia of the testis: recommendations from the International Collaboration on Cancer Reporting.

We here describe the development of an evidence-based cancer dataset by an International Collaboration on Cancer Reporting expert panel for the reporting of primary testicular neoplasia, and present the 'required' and 'recommended' elements to be included in the pathology report, as well as a commentary. This dataset encompasses the updated 2016 World Health Organisation classification of urological tumours, the results of an International Society of Urological Pathology consultation, and also staging with our preferred method: the American Joint Committee on Cancer version 8. Implementation of this dataset will facilitate consistent and accurate data collection between different cohorts, facilitate research, and hopefully result in improved patient management.

Dataset for reporting of carcinoma of the urethra (in urethrectomy specimens): recommendations from the International Collaboration on Cancer Reporting (ICCR).

The International Collaboration on Cancer Reporting (ICCR) is a not-for-profit organisation sponsored by the Royal Colleges of Pathologists of Australasia and the United Kingdom, the College of American Pathologists, the Canadian Association of Pathologists in association with the Canadian Partnership Against Cancer, the European Society of Pathology, the American Society of Clinical Pathology and the Faculty of Pathology, Royal College of Physicians of Ireland. Its goal is to produce standardised, internationally agreed-upon, evidence-based datasets for cancer pathology reporting throughout the world. This paper describes the development of a cancer dataset by the multidisciplinary ICCR expert panel for the reporting of carcinoma of the urethra in urethrectomy specimens. The dataset is composed of 'required' (mandatory) and 'recommended' (non-mandatory) elements, which are based on a review of the most recent evidence and supported by explanatory commentary. Fourteen required elements and eight recommended elements were agreed by the international dataset authoring committee to represent the essential/required (core) and recommended (non-core) information for the reporting of carcinoma of the urethra in urethrectomy specimens. Use of an internationally agreed, structured pathology dataset for reporting carcinoma of the urethra (in urethrectomy specimens) will provide the necessary information for optimal patient management, will facilitate consistent data collection and will provide valuable data for research and international benchmarking. The dataset will be valuable for those countries and institutions that are not in a position to develop their own datasets.

Data set for the reporting of carcinoma of renal tubular origin: recommendations from the International Collaboration on Cancer Reporting (ICCR).

AIMS: The International Collaboration on Cancer Reporting (ICCR) has provided detailed data sets based upon the published reporting protocols of the Royal College of Pathologists, the Royal College of Pathologists of Australasia and the College of American Pathologists. METHODS AND RESULTS: The data set for carcinomas of renal tubular origin treated by nephrectomy was developed to provide a minimum structured reporting template suitable for international use, and incorporated recommendations from the 2012 Vancouver Consensus Conference of the International Society of Urological Pathology (ISUP) and the fourth edition of the World Health Organisation Bluebook on tumours of the urinary and male genital systems published in 2016. Reporting elements were divided into those, which are required and recommended components of the report. Required elements are: specimen laterality, operative procedure, attached structures, tumour focality, tumour dimension, tumour type, WHO/ISUP grade, sarcomatoid/rhabdoid morphology, tumour necrosis, extent of invasion, lymph node status, surgical margin status, AJCC TNM staging and co-existing pathology. Recommended reporting elements are: pre-operative treatment, details of tissue removed for experimental purposes prior to submission, site of tumour(s) block identification key, extent of sarcomatoid and/or rhabdoid component, extent of necrosis, presence of tumour in renal vein wall, lymphovascular invasion and lymph node status (size of largest focus and extranodal extension). CONCLUSIONS: It is anticipated that the implementation of this data set in routine clinical practice will inform patient treatment as well as provide standardised information relating to outcome prediction. The harmonisation of data reporting should also facilitate international research collaborations.

Analytical validation of a standardised scoring protocol for Ki67 immunohistochemistry on breast cancer excision whole sections: an international multicentre collaboration.

AIMS: The nuclear proliferation marker Ki67 assayed by immunohistochemistry has multiple potential uses in breast cancer, but an unacceptable level of interlaboratory variability has hampered its clinical utility. The International Ki67 in Breast Cancer Working Group has undertaken a systematic programme to determine whether Ki67 measurement can be analytically validated and standardised among laboratories. This study addresses whether acceptable scoring reproducibility can be achieved on excision whole sections. METHODS AND RESULTS: Adjacent sections from 30 primary ER+ breast cancers were centrally stained for Ki67 and sections were circulated among 23 pathologists in 12 countries. All pathologists scored Ki67 by two methods: (i) global: four fields of 100 tumour cells each were selected to reflect observed heterogeneity in nuclear staining; (ii) hot-spot: the field with highest apparent Ki67 index was selected and up to 500 cells scored. The intraclass correlation coefficient (ICC) for the global method [confidence interval (CI) = 0.87; 95% CI = 0.799-0.93] marginally met the prespecified success criterion (lower 95% CI ≥ 0.8), while the ICC for the hot-spot method (0.83; 95% CI = 0.74-0.90) did not. Visually, interobserver concordance in location of selected hot-spots varies between cases. The median times for scoring were 9 and 6 min for global and hot-spot methods, respectively. CONCLUSIONS: The global scoring method demonstrates adequate reproducibility to warrant next steps towards evaluation for technical and clinical validity in appropriate cohorts of cases. The time taken for scoring by either method is practical using counting software we are making publicly available. Establishment of external quality assessment schemes is likely to improve the reproducibility between laboratories further.

Comparison of clinical and neuropathological diagnoses of neurodegenerative diseases in two centres from the Brains for Dementia Research (BDR) cohort.

Early detection and accurate diagnosis of neurodegenerative disorders may provide better epidemiological data, closer monitoring of disease progression and enable more specialised intervention. We analysed the clinical records and pathology of brain donations from 180 patients from two Brains for Dementia Research cohorts to determine the agreement between in-life clinical diagnosis and post-mortem pathological results. Clinical diagnosis was extracted from medical records and cases assigned into broad clinical groups; control, Alzheimer's disease (AD), vascular dementia (CVD), dementia with Lewy bodies (DLB), frontotemporal dementia (FTD) and combined diseases. Pathology was assessed blindly, and cases categorised into; control, intermediate AD, severe AD, CVD, AD and CVD combined, DLB, AD and DLB combined and frontotemporal lobar degeneration (FTLD), according to the major contributing pathologies. In more than a third of cases clinical diagnosis was different from final neuropathological diagnosis. The majority of AD, DLB and control clinical groups matched the pathological diagnosis; however, thirty-five percent of clinical AD cases showed additional prominent CVD or DLB pathology which had not been diagnosed clinically and twenty-five percent of clinical control cases were found to have intermediate Tau pathology (modified Braak stage III-IV) or CVD. CVD and AD + CVD clinical groups showed an average of only thirty-two percent pathological correlation, the majority actually having no CVD, and fifty-three percent of pathologically identified FTLD cases had been incorrectly clinically diagnosed. Our results underlie the importance of neuropathological confirmation of clinical diagnosis. The relatively low accuracy of clinical diagnosis demonstrates the need for standardised and validated diagnostic assessment procedures.