Surgical pathology--second reviews, institutional reviews, audits, and correlations: what's out there? Error or diagnostic variation?

Second opinion for pulmonary and pleural cytology is valuable for patient care

INTRODUCTION

Thoracic cytology can be challenging due to limited procured material or overlapping morphology between benign and malignant entities. In such cases, expert consultation might be sought. This study aimed to characterize all pulmonary and pleural cytology consult cases submitted to our practice and provide recommendations on approaching difficult cases.

MATERIALS AND METHODS

All thoracic (pulmonary and pleural) cytology cases submitted for expert consultation to the University of Michigan (MLabs) from 2013 to mid-2022 were reviewed. Cases where cytology was only part of a hematopathology or surgical pathology consult were excluded. Patient demographics, specimen location, procedure performed, referring diagnosis, and our diagnoses were recorded for each case. Diagnoses were categorized according to the Papanicolaou Society of Cytopathology recommendations for pulmonary and effusion cytology. Discordant diagnoses were stratified as major or minor. Data was analyzed using chi-square analysis and logistic models.

RESULTS

We received 784 thoracic cytology consult cases, including 530 exfoliative samples and 307 fine-needle aspirations. The most common anatomic locations sampled were the bronchial wall (n = 194, 23%), lung nodule (n = 322, 38%), and pleura (n = 296, 35%). 413 cases had a diagnostic discrepancy (48.3%), with 274 (66%) minor and 139 (34%) major discrepancies. By location, pleural effusion specimens had the highest probability of a discrepant diagnosis (P = 0.003). By specimen type, fine-needle aspiration samples were more likely to have a discrepant diagnosis (P = 0.09), approaching significance.

CONCLUSION

Nearly half of the thoracic cytology cases submitted for expert second opinion had diagnostic discrepancies. Consequently, consulting a tertiary medical care center with cytopathology expertise for challenging thoracic cytology diagnoses is beneficial.

The experience of introducing telepathology in Mongolia

Background

Anatomical pathology care services play an essential role in cancer diagnosis through histological analysis, effective treatment of patients, and determination of prognosis. Therefore, quality control is necessary for the diagnosis of pathology. Based on this need, telepathology technology is rapidly developing in the world. This study aimed to share the experience of implementing telepathology case consultation between Mongolian and Japanese expert pathologists.

Methods

The study included 173 cases that required telepathology consultation, which was complicated and doubtful in diagnosis, submitted by Mongolian pathologists between May 2019 and April 2022. The scanned digital slides were transmitted with the help of the LOOKREC cloud-based system, and the expert pathologists of Hiroshima University Hospital, Japan, browsed the images through the data on the internet and their advice and made a mutual diagnosis.

Results

During the study period, 173 cases were consulted. Out of 58.4% of all cases, consultation reports were released in 2022. The majority of the cases in 2020 had a mean standard deviation turn-around time of 4.2±6.2 days. The most cases were from the lung and mediastinum were 29.4%, followed by head and neck at 12.6%, the bone at 11.9%, lymph nodes at 8.4%, GIT at 7.7%, soft tissues at 6.3%, etc. Comparing the sample submission of biopsy and cytology was significantly higher in the under 10 years of an experienced group than over 10 years of an experienced group (p<.005). The diagnostic agreement between submitter Mongolian pathologists and expert Japanese pathologists was 82.7%, and disagreement was 17.3% of all cases, with a sensitivity of 67.3% and specificity of 85.5%.

Conclusions

Telepathology could save many lost opportunities and play an essential role in developing quality control and surgical pathology in Mongolia. This digital technology and the appropriate strategy and policy of the government could accelerate the overall pathology field development.

Second Opinion in the Italian Organ Procurement Transplantation: The Pathologist Is In

Second opinion consultation is a well-established practice in different clinical settings of diagnostic medicine. However, little is known about second opinion consultation activity in transplantation, and even less is known about it concerning donor assessment. The consultations provided by the second opinion service led to the safer and homogeneous management of donors with a history of malignancy or ongoing neoplasm by transplant centers. Indeed, two of the most important aspects are the reduction of semantic differences in cancer reporting and the standardization of procedures, which are mainly due to the different settings and logistics of different pathology services. This article aims to discuss the role and the future of the second opinion in Italy during organ procurement, highlighting the critical issues and areas for improvement.

Reforms, Errors, and Dermatopathology Malpractice: Then and Now: A Comprehensive Retrospective

Medical malpractice occurs when a hospital, doctor, or other health care professional, through a negligent act or omission, causes an injury to a patient. The negligence might be the result of errors in diagnosis, treatment, aftercare, or health management. To be considered medical malpractice under the law, the claim must violate the standard of care, the injury must be caused by the negligence and, last but most certainly not least, the injury must result in significant damages. This review is an overview of medicolegal issues specific to the practice of Dermatopathology with the caveat that most are likely pertinent to other specialties of pathology as well. The safety of patients remains the priority in pathology as it does in any medical undertaking, and this is no different in the practice of Dermatopathology. The review is broadly divided in 2 parts-we begin with an overview of tort reforms, advocated by physicians to reduce costs associated with malpractice defense. In the second part we address practical issues specific to the practice of pathology and dermatopathology. These include among others, errors-related to the biopsy type, inadequacy of clinical information regarding the lesion that is biopsied, role of interstate dermatopathology as well as examples of select entities commonly misdiagnosed in dermatopathology. In the last decade, artificial intelligence (AI) has moved to the forefront of technology. While research into the uses of AI in pathology is promising, the use of AI in diagnostic practice is still somewhat uncommon. Given that AI is not fully integrated routinely as a diagnostic adjunct, its' impact on pathology-specific medicolegal issues cannot, as yet at least, be defined. Restriction of medical malpractice is of particular relevance in the COVID-19 era, a period that is anything but normal. The response of states with specific pandemic-related guidelines is addressed with the caveat that this particular issue is only covered in select states. Furthermore, given that the COVID pandemic is only a year old, while it does not appear to have had an immediate impact on pathology-specific medicolegal matters, it is possible that the role of COVID on this issue, if any at all, will and can only be fully defined a few years down the line.

Identification of Molecular Alterations Challenging Initial Pathologic Classification in Cases of Clinician-Initiated Next-Generation Sequencing Testing

OBJECTIVES

Large gene panel next-generation sequencing (NGS) is a powerful tool capable of generating predictive data on cancer prognosis and response to specific therapeutic interventions. The utility of large panel NGS data on tumor classification, however, may be underappreciated because of a workflow that often circumvents the surgical pathologist. We sought to describe cases in which NGS data lead to an unanticipated change in tumor classification and to discuss current workflow practices of NGS testing that limit its use as a diagnostic adjunct.

METHODS

We performed a retrospective review to identify cases in which NGS testing uncovered data that led to a revision of the initial pathologic diagnosis that an outside or in-house pathologist had made.

RESULTS

Nine cases are presented in which NGS data provided insights that led to a revision of the original pathologic diagnosis. Distinctive molecular signatures, mutational signatures, fusions, or identification of viral sequencing provided the critical evidence on which these tumors were reclassified.

CONCLUSIONS

The current workflow of NGS testing should always include the surgical pathologist as an active partner to ensure that the molecular results are fully reflected in the final diagnosis. In some instances, active participation by the surgical pathologist may require amendment of previously issued pathology reports.

Verification and Validation of Digital Pathology (Whole Slide Imaging) for Primary Histopathological Diagnosis: All Wales Experience

Aims:

The study is aimed to verify Aperio AT2 scanner for reporting on the digital pathology platform (DP) and to validate the cohort of pathologists in the interpretation of DP for routine diagnostic histopathological services in Wales, United Kingdom.

Materials, Methods and Results:

This was a large multicenter study involving seven hospitals across Wales and unique with 22 (largest number) pathologists participating. 7491 slides from 3001 cases were scanned on Leica Aperio AT2 scanner and reported on digital workstations with Leica software of e-slide manager. A senior pathology fellow compared DP reports with authorized reports on glass slide (GS). A panel of expert pathologists reviewed the discrepant cases under multiheader microscope to establish ground truth. 2745 out of 3001 (91%) cases showed complete concordance between DP and GS reports. Two hundred and fifty-six cases showed discrepancies in diagnosis, of which 170 (5.6%) were deemed of no clinical significance by the review panel. There were 86 (2.9%) clinically significant discrepancies in the diagnosis between DP and GS. The concordance was raised to 97.1% after discounting clinically insignificant discrepancies. Ground truth lay with DP in 28 out of 86 clinically significant discrepancies and with GS in 58 cases. Sensitivity of DP was 98.07% (confidence interval [CI] 97.57–98.56%); for GS was 99.07% (CI 98.72–99.41%).

Conclusions:

We concluded that Leica Aperio AT2 scanner produces adequate quality of images for routine histopathologic diagnosis. Pathologists were able to diagnose in DP with good concordance as with GS.

Strengths and Limitations of this Study:

Strengths of this study – This was a prospective blind study. Different pathologists reported digital and glass arms at different times giving an ambience of real-time reporting. There was standardized use of software and hardware across Wales. A strong managerial support from efficiency through the technology group was a key factor for the implementation of the study.

Limitations:

This study did not include Cytopathology and in situ hybridization slides. Difficulty in achieving surgical pathology practise standardization across the whole country contributed to intra-observer variations.

Remote Reporting from Home for Primary Diagnosis in Surgical Pathology: A Tertiary Oncology Center Experience during the COVID-19 Pandemic

BACKGROUND

The COVID-19 pandemic accelerated the widespread adoption of digital pathology (DP) for primary diagnosis in surgical pathology. This paradigm shift is likely to influence how we function routinely in the postpandemic era. We present learnings from early adoption of DP for a live digital sign-out from home in a risk-mitigated environment.

MATERIALS AND METHODS

We aimed to validate DP for remote reporting from home in a real-time environment and evaluate the parameters influencing the efficiency of a digital workflow. Eighteen pathologists prospectively validated DP for remote use on 567 biopsy cases including 616 individual parts from 7 subspecialties over a duration from March 21, 2020, to June 30, 2020. The slides were digitized using Roche Ventana DP200 whole-slide scanner and reported from respective homes in a risk-mitigated environment.

RESULTS

Following re-review of glass slides, there was no major discordance and 1.2% (n = 7/567) minor discordance. The deferral rate was 4.5%. All pathologists reported from their respective homes from laptops with an average network speed of 20 megabits per second.

CONCLUSION

We successfully validated and adopted a digital workflow for remote reporting with available resources and were able to provide our patients, an undisrupted access to subspecialty expertise during these unprecedented times.

Errors in prostate core biopsy diagnosis in an era of specialisation and double reporting

AIM

To examine the effects of specialist reporting on error rates in prostate core biopsy diagnosis.

METHOD

Biopsies were reported by eight specialist uropathologists over 3 years. New cancer diagnoses were double-reported and all biopsies were reviewed for the multidisciplinary team (MDT) meeting. Diagnostic alterations were recorded in supplementary reports and error rates were compared with a decade previously.

RESULTS

2600 biopsies were reported. 64.1% contained adenocarcinoma, a 19.7% increase. The false-positive error rate had reduced from 0.4% to 0.06%. The false-negative error rate had increased from 1.5% to 1.8%, but represented fewer absolute errors due to increased cancer incidence.

CONCLUSIONS

Specialisation and double-reporting have reduced false-positive errors. MDT review of negative cores continues to identify a very low number of false-negative errors. Our data represents a 'gold standard' for prostate biopsy diagnostic error rates. Increased use of MRI-targeted biopsies may alter error rates and their future clinical significance.

Second thoughts: Emergency clinicians see value in secondary interpretations

OBJECTIVE

Secondary interpretations of imaging studies performed at another facility are increasingly common in radiology, particularly emergency radiology. While data suggests there are often discrepancies found between original and secondary reports, the benefit from the clinician perspective is unclear.

METHODS AND MATERIALS

An anonymous electronic survey on secondary interpretations was circulated to 58 attending adult emergency physicians and trauma surgeons at a Level I trauma center from March 2018 to April 2018. Chi-squared testing was used for statistical analysis.

RESULTS

80.8% of respondents requested secondary interpretations either "always" or "most of the time." Over half of the respondents cited trust in the house radiologist interpretation as the primary reason for secondary interpretation requests. 92.3% and 84.6% of respondents felt that the ability to obtain second interpretations improves patient care and facilitates disposition, respectively. 88.5% of respondents reported reduced imaging utilization due to secondary reads. When presented with conflicting interpretations, all trauma surgeons would rely on the in-house interpretation, whereas 50% of the emergency physicians would pursue further imaging (p < 0.05). 96.2% of respondents were uncertain about insurance coverage of secondary interpretations, but 73.1% would continue to order them, regardless.

CONCLUSION

Secondary reads were heavily utilized, felt to influence patient care, reduced additional imaging and aided in disposition, suggesting clinical benefit. When presented with conflicting reports, trauma surgeons would rely on the in-house interpretation whereas emergency physicians more often opted to pursue additional imaging. Most respondents would still request secondary interpretations despite being unaware of insurance coverage for these interpretations.

Digital pathology for second opinion consultation and donor assessment during organ procurement: Review of the literature and guidance for deployment in transplant practice

Telepathology has been an important application for second opinion consultation ever since the introduction of digital pathology. However, little is known regarding teleconsultation for second opinion in transplantation. There is also limited literature on telepathology during organ donor procurement, typically utilized when general pathologists on-call request back-up to help assess donor biopsies for organ suitability or to diagnose newly discovered tumors with urgent time constraints. In this review, we searched Pubmed/Embase and websites of transplant organizations to collect and analyze published evidence on teleconsultation for donor evaluation and organ procurement. Of 2725 records retrieved using the key terms 'telepathology', 'second opinion' and 'transplantation', 26 suitable studies were included. Most records were from North America and included validation studies of telepathology being used for remote frozen section interpretation of donor biopsies with whole slide imaging. The data from these published studies supports the transition towards digital teleconsultation in transplant settings where consultations among pathologists are still handled by pathologists being called on site, via telephone and/or email.

Review of diagnostic error in anatomical pathology and the role and value of second opinions in error prevention

Aims

Diagnostic/interpretative accuracy can be challenging in anatomical pathology due to the subjective element of the diagnostic process. This can lead to false-negative or false-positive diagnoses of malignancy, variations in grading and diagnostic misclassification of a condition.

It is imperative that an accurate diagnosis is achieved so that an appropriate and timely treatment is administered to the patient, for example, the success of targeted molecular therapeutic options for treatment of cancer is dependent on accurate anatomical pathology diagnoses being issued.

Methods

A literature review of diagnostic accuracy in selected specimen categories was undertaken and was compared with data on metropolitan and regional pathologist diagnostic proficiency performance in an external quality assurance programme from surveys provided 2015–2017. For each specimen category, cases having attracted a diagnostic inaccuracy (ie, major discordance) of ≥20% and cases attracting a combined error rate (ie, major and minor discordance) of ≥30% are reviewed and discussed.

Results

The rate of inaccurate diagnoses (assessed as a major discordance) ranged from 3% to 9% among the different specimen groups, with highest mean percentage of inaccurate diagnoses in gynaecology, dermatopathology and gastrointestinal specimens.

Conclusions

It was possible to ascertain that gynaecology, dermatopathology and gastrointestinal specimens had presented the greatest diagnostic challenge to the participant pathologists, determined as highest rate of diagnostic inaccuracy, that is, major discordance with respective case target diagnoses.

Through a combination of routine second opinions, directed retrospective peer review and participation in appropriate external quality assurance schemes, the risk associated with these diagnoses can be minimised.

Pathologists' Use of Second Opinions in Interpretation of Melanocytic Cutaneous Lesions: Policies, Practices, and Perceptions

BACKGROUND

Research examining the role of second opinions in pathology for diagnosis of melanocytic lesions is limited.

OBJECTIVE

To assess current laboratory policies, clinical use of second opinions, and pathologists' perceptions of second opinions for melanocytic lesions.

MATERIALS AND METHODS

Cross-sectional data collected from 207 pathologists in 10 US states who diagnose melanocytic lesions. The web-based survey ascertained pathologists' professional information, laboratory second opinion policy, use of second opinions, and perceptions of second opinion value for melanocytic lesions.

RESULTS

Laboratory policies required second opinions for 31% of pathologists and most commonly required for melanoma in situ (26%) and invasive melanoma (30%). In practice, most pathologists reported requesting second opinions for melanocytic tumors of uncertain malignant potential (85%) and atypical Spitzoid lesions (88%). Most pathologists perceived that second opinions increased interpretive accuracy (78%) and protected them from malpractice lawsuits (62%).

CONCLUSION

Use of second opinions in clinical practice is greater than that required by laboratory policies, especially for melanocytic tumors of uncertain malignant potential and atypical Spitzoid lesions. Quality of care in surgical interventions for atypical melanocytic proliferations critically depends on the accuracy of diagnosis in pathology reporting. Future research should examine the extent to which second opinions improve accuracy of melanocytic lesion diagnosis.

A structured latent model for ovarian carcinoma subtyping from histopathology slides

Accurate subtyping of ovarian carcinomas is an increasingly critical and often challenging diagnostic process. This work focuses on the development of an automatic classification model for ovarian carcinoma subtyping. Specifically, we present a novel clinically inspired contextual model for histopathology image subtyping of ovarian carcinomas. A whole slide image is modelled using a collection of tissue patches extracted at multiple magnifications. An efficient and effective feature learning strategy is used for feature representation of a tissue patch. The locations of salient, discriminative tissue regions are treated as latent variables allowing the model to explicitly ignore portions of the large tissue section that are unimportant for classification. These latent variables are considered in a structured formulation to model the contextual information represented from the multi-magnification analysis of tissues. A novel, structured latent support vector machine formulation is defined and used to combine information from multiple magnifications while simultaneously operating within the latent variable framework. The structural and contextual nature of our method addresses the challenges of intra-class variation and pathologists' workload, which are prevalent in histopathology image classification. Extensive experiments on a dataset of 133 patients demonstrate the efficacy and accuracy of the proposed method against state-of-the-art approaches for histopathology image classification. We achieve an average multi-class classification accuracy of 90%, outperforming existing works while obtaining substantial agreement with six clinicians tested on the same dataset.

The Empirical Foundations of Telepathology: Evidence of Feasibility and Intermediate Effects

INTRODUCTION

Telepathology evolved from video microscopy (i.e., "television microscopy") research in the early 1950s to video microscopy used in basic research in the biological sciences to a basic diagnostic tool in telemedicine clinical applications. Its genesis can be traced to pioneering feasibility studies regarding the importance of color and other image-based parameters for rendering diagnoses and a series of studies assessing concordance of virtual slide and light microscopy diagnoses. This article documents the empirical foundations of telepathology.

METHODS

A selective review of the research literature during the past decade (2005-2016) was conducted using robust research design and adequate sample size as criteria for inclusion.

CONCLUSIONS

The evidence regarding feasibility/acceptance of telepathology and related information technology applications has been well documented for several decades. The majority of evidentiary studies focused on intermediate outcomes, as indicated by comparability between telepathology and conventional light microscopy. A consistent trend of concordance between the two modalities was observed in terms of diagnostic accuracy and reliability. Additional benefits include use of telepathology and whole slide imaging for teaching, research, and outreach to resource-limited countries. Challenges still exist, however, in terms of use of telepathology as an effective diagnostic modality in clinical practice.

The surgical pathology laboratory in Mwanza, Tanzania: a survey on the reproducibility of diagnoses after the first years of autonomous activity

BACKGROUND

In 2000, an Italian non-governmental organisation (NGO) began a 9-year project to establish a surgical pathology laboratory at the Bugando Medical Centre (BMC) in Mwanza, Tanzania, a country with a low Human Development Index (HDI), and as of 2009, the laboratory was operating autonomously. The present survey aims to evaluate the reproducibility of histological and cytological diagnoses assigned in the laboratory's early years of autonomous activity. We selected a random sample of 196 histological and cytological diagnoses issued in 2010-2011 at the BMC surgical pathology laboratory. The corresponding samples were sent to Italy for review by Italian senior pathologists, who were blinded to the local results. Samples were classified into four diagnostic categories: malignant, benign, inflammatory, and suspicious. The two-observer kappa-statistic for categorised (qualitative) data was then calculated to measure diagnostic concordance between the local Tanzanian pathologists and Italian senior pathologists. The k-Cohen was calculated for concordance in the overall study sample. Concordance and discordance rates were also stratified by subset: general adult, paediatric/adolescent, and lymphoproliferative histopathological diagnoses; fluid and fine needle aspiration (FNA) cytological diagnoses; and PAP tests. Discordance was also categorised by the corresponding hypothetical clinical implications: high, intermediate, and not significant.

RESULTS

Overall concordance was 85.2% (167 of 196 diagnoses), with a k-Cohen of 0.7691 (P = 0.0000). Very high concordance was observed in the subsets of adult general pathological diagnoses (90%) and paediatric/adolescent pathological diagnoses (91.18%). Concordance in the subset of PAP tests was 75%, and for fluid/FNA cytological diagnoses it was 56.52%. Concordance among 12 histological subtypes of lymphoma was 75.86%, with substantial discordance observed in the diagnosis of Burkitt lymphoma (five cases diagnosed by Italian pathologists versus 2 by local pathologists). The overall proportion of discordance with high hypothetical clinical implications was 6.1% (12 diagnoses).

CONCLUSION

This blind review of diagnoses assigned in Tanzania, a country with low HDI, and in Italy, a country with a very high HDI, seemed to be a sensitive and effective method to identify areas of potential error and may represent a reference point for future, more detailed quality control processes or audits of surgical pathology services located in limited-resource regions.

Evaluation of 12 strategies for obtaining second opinions to improve interpretation of breast histopathology: simulation study

OBJECTIVE

 To evaluate the potential effect of second opinions on improving the accuracy of diagnostic interpretation of breast histopathology.

DESIGN

 Simulation study.

SETTING

 12 different strategies for acquiring independent second opinions.

PARTICIPANTS

 Interpretations of 240 breast biopsy specimens by 115 pathologists, one slide for each case, compared with reference diagnoses derived by expert consensus.

MAIN OUTCOME MEASURES

 Misclassification rates for individual pathologists and for 12 simulated strategies for second opinions. Simulations compared accuracy of diagnoses from single pathologists with that of diagnoses based on pairing interpretations from first and second independent pathologists, where resolution of disagreements was by an independent third pathologist. 12 strategies were evaluated in which acquisition of second opinions depended on initial diagnoses, assessment of case difficulty or borderline characteristics, pathologists' clinical volumes, or whether a second opinion was required by policy or desired by the pathologists. The 240 cases included benign without atypia (10% non-proliferative, 20% proliferative without atypia), atypia (30%), ductal carcinoma in situ (DCIS, 30%), and invasive cancer (10%). Overall misclassification rates and agreement statistics depended on the composition of the test set, which included a higher prevalence of difficult cases than in typical practice.

RESULTS

 Misclassification rates significantly decreased (P<0.001) with all second opinion strategies except for the strategy limiting second opinions only to cases of invasive cancer. The overall misclassification rate decreased from 24.7% to 18.1% when all cases received second opinions (P<0.001). Obtaining both first and second opinions from pathologists with a high volume (≥10 breast biopsy specimens weekly) resulted in the lowest misclassification rate in this test set (14.3%, 95% confidence interval 10.9% to 18.0%). Obtaining second opinions only for cases with initial interpretations of atypia, DCIS, or invasive cancer decreased the over-interpretation of benign cases without atypia from 12.9% to 6.0%. Atypia cases had the highest misclassification rate after single interpretation (52.2%), remaining at more than 34% in all second opinion scenarios.

CONCLUSION

 Second opinions can statistically significantly improve diagnostic agreement for pathologists' interpretations of breast biopsy specimens; however, variability in diagnosis will not be completely eliminated, especially for breast specimens with atypia.

A nationwide telepathology consultation and quality control program in China: implementation and result analysis

Background

Telepathology may play an important role in pathology consultation and quality control for cancer diagnosis in China, as the country has the largest population of cancer patients worldwide. In 2011, the Pathology Quality Control Center of China and Ministry of Health developed and implemented a nationwide telepathology consultation and quality control program for cancer diagnosis in China. We here report the results of the two-year implementation and experiences.

Methods

the program built an Internet based telepathology platform to connect participating hospitals and expert consultants. The hardware and software used for the platform were validated in previous validation studies in China. The program had three regional centers consisting of Peking Union Medical College, Huasi Medical College of Sichuan and 2nd affiliated hospital of Zhejiang University. It also had 20 provincial consultation centers based in the provincial referral hospitals. 80 provincial or national pathologists served as expert consultants for the program, providing telepathology consultation for cancer diagnosis for more than 60 participating hospitals.

Results

from 2011 to July 2013, 16,247 pathology cases were submitted to the platform for consultation. Among them, 84% were due to diagnostic difficulty and 16% were due to request by patients. The preliminary diagnosis provided by submitting pathologists were in agreement with expert opinion in 59.8% of cases but was in disagreement with expert opinion in 24.2% of cases. 16.0% of cases were not provided with preliminary diagnosis. The distribution of pathology cases by system or organ were: digestive system, 17.3%; gynecologic system, 16.7%; head and neck, 15.7%; bone and soft tissue, 10.4%; lung and mediastinum, 8.6%; breast, 7.6%; urinary system, 7.5%; hematopathology, 6.4%; skin, 5.2%; neuropathology, 2.5% and cytopathology, 1.3%. Expert consultants also provided assessment of quality of slide preparation and staining, online lectures and guidance for pathology quality control.

Conclusion

our results of two years' implementation indicated that telepathology could solve the problem of uneven distribution of pathology resources and provide a solution for countrywide pathology quality control in China. Telepathology could play an important role in improving pathology diagnosis in China.

Second opinion in breast pathology: policy, practice and perception

AIMS

To assess the laboratory policies, pathologists' clinical practice and perceptions about the value of second opinions for breast pathology cases among pathologists practising in the USA.

METHODS

Cross-sectional data were collected from 252 pathologists who interpret breast specimens in eight states using a web-based survey. Descriptive statistics were used to characterise findings.

RESULTS

Most participants had >10 years of experience interpreting breast specimens (64%), were not affiliated with academic centres (73%) and were not considered experts by their peers (79%). Laboratory policies mandating second opinions varied by diagnosis: invasive cancer 65%; ductal carcinoma in situ (DCIS) 56%; atypical ductal hyperplasia 36% and other benign cases 33%. 81% obtained second opinions in the absence of policies. Participants believed they improve diagnostic accuracy (96%) and protect from malpractice suits (83%), and were easy to obtain, did not take too much time and did not make them look less adequate. The most common (60%) approach to resolving differences between the first and second opinion is to ask for a third opinion, followed by reaching a consensus.

CONCLUSIONS

Laboratory-based second opinion policies vary for breast pathology but are most common for invasive cancer and DCIS cases. Pathologists have favourable attitudes towards second opinions, adhere to policies and obtain them even when policies are absent. Those without a formal policy may benefit from supportive clinical practices and systems that help obtain second opinions.

Whole slide imaging diagnostic concordance with light microscopy for breast needle biopsies

This study investigated the diagnostic accuracy of whole slide imaging (WSI) in breast needle biopsy diagnosis in comparison with standard light microscopy (LM). The study examined the effects of image capture magnification and computer monitor quality on diagnostic concordance of WSI and LM. Four pathologists rendered diagnoses using WSI to examine 85 breast biopsies (92 parts; 786 slides) consisting of benign and malignant cases. Each WSI case was evaluated using images captured at either ×20 or ×40 magnifications and viewed using a Digital Imaging and Communication in Medicine (DICOM) grade, color-calibrated monitor or a standard, desktop liquid-crystal display (LCD) monitor. For each combination, the WSI result was compared with the original, LM diagnosis. The overall concordance rate observed between WSI and LM was 97.1% (95% confidence intervals [CI]: 94.3%-98.5%). After a washout period, all cases were reviewed a second time by each pathologist after using LM, and the second LM diagnosis was compared with the WSI diagnosis rendered by the same pathologist. Intraobserver concordance between WSI and LM was 95.4% (95% CI: 92.2%-97.4%). The second LM diagnoses were also compared with the original LM diagnoses, and the observed interobserver LM concordance rate was 97.3% (95% CI: 93.1%-99.0%). The study data demonstrated that breast needle biopsy diagnoses rendered by WSI were equivalent to diagnoses rendered by LM. No diagnostic differences were detected between the underlying viewing system parameters of monitor quality and image capture resolution. The results of this study demonstrated that WSI can be effectively used in subspecialty diagnostic cases where a minimum amount of tissue is available.

Changes in breast cancer reports after pathology second opinion

Breast cancer pathology reports contain valuable information about the histologic diagnosis, prognostic factors and predictive indicators of therapeutic response. A second opinion may be requested by medical oncologists and surgeons, when a patient is referred from another institution for treatment. We report the experience with pathology second opinion in selected patients referred to the Breast Oncology Unit. 205 cases referred to the Breast Oncology Unit were selected for second opinion after clinical evaluation, between 2002 and 2012. The cases reviewed included 102 core needle biopsies, 88 surgical specimens from the breast and 18 lymphadenopathies, 14 from the axillary region. Pathology second opinion was based on a review of hematoxylin-eosin preparations, recuts of submitted paraffin blocks and written external pathology reports. Immunohistochemical studies for hormone receptors, HER2, myoepithelial cells, and other markers were performed in selected cases. A case was reclassified as showing major change when second opinion showed a potential for significant change in prognosis or treatment. Otherwise, it was considered to represent minor change or to be concordant. In 52 cases (25.4%), the pathology review showed changes. Thirty-three (16%) patients were reclassified for major changes and 19 (9.2%) as minor changes. In six patients, more than one major change was identified. The major discrepancies identified were related to the histologic classification (12 cases), the presence or absence of invasion in ductal carcinoma (15 cases), the results of hormone receptors (5 cases), and HER2 (7 cases). Major changes in histologic classification included two cases diagnosed as invasive ductal carcinoma and reclassified as benign, four cases with diagnosis of breast cancer reclassified as metastatic lung cancer, one case diagnosed as small cell carcinoma of lung metastatic in the breast, reclassified as primary carcinoma of the breast, and three cases with diagnosis of breast cancer in the axilla reclassified as primary cutaneous adnexal carcinomas (2) and metastatic melanoma (1), respectively. In two cases, the histologic type of the primary breast tumor was changed. Second opinion in breast pathology may uncover significant discrepancies that impact on patient management and prognosis. Major discrepancies are most frequently related to the assessment of the presence or absence of invasion in ductal carcinoma, the results of predictive makers of therapeutic response, and the differential diagnosis of breast cancer and nonmammary tumors in the breast, the axilla, and at distant sites.

Error rates in a clinical data repository: lessons from the transition to electronic data transfer--a descriptive study

OBJECTIVE

Data errors are a well-documented part of clinical datasets as is their potential to confound downstream analysis. In this study, we explore the reliability of manually transcribed data across different pathology fields in a prostate cancer database and also measure error rates attributable to the source data.

DESIGN

Descriptive study.

SETTING

Specialist urology service at a single centre in metropolitan Victoria in Australia.

PARTICIPANTS

Between 2004 and 2011, 1471 patients underwent radical prostatectomy at our institution. In a large proportion of these cases, clinicopathological variables were recorded by manual data-entry. In 2011, we obtained electronic versions of the same printed pathology reports for our cohort. The data were electronically imported in parallel to any existing manual entry record enabling direct comparison between them.

OUTCOME MEASURES

Error rates of manually entered data compared with electronically imported data across clinicopathological fields.

RESULTS

421 patients had at least 10 comparable pathology fields between the electronic import and manual records and were selected for study. 320 patients had concordant data between manually entered and electronically populated fields in a median of 12 pathology fields (range 10-13), indicating an outright accuracy in manually entered pathology data in 76% of patients. Across all fields, the error rate was 2.8%, while individual field error ranges from 0.5% to 6.4%. Fields in text formats were significantly more error-prone than those with direct measurements or involving numerical figures (p<0.001). 971 cases were available for review of error within the source data, with figures of 0.1-0.9%.

CONCLUSIONS

While the overall rate of error was low in manually entered data, individual pathology fields were variably prone to error. High-quality pathology data can be obtained for both prospective and retrospective parts of our data repository and the electronic checking of source pathology data for error is feasible.

Validation of whole slide imaging for primary diagnosis in surgical pathology

CONTEXT

High-resolution scanning technology provides an opportunity for pathologists to make diagnoses directly from whole slide images (WSIs), but few studies have attempted to validate the diagnoses so obtained.

OBJECTIVE

To compare WSI versus microscope slide diagnoses of previously interpreted cases after a 1-year delayed re-review ("wash-out") period.

DESIGN

An a priori power study estimated that 450 cases might be needed to demonstrate noninferiority, based on a null hypothesis: "The true difference in major discrepancies between WSI and microscope slide review is greater than 4%." Slides of consecutive cases interpreted by 2 pathologists 1 year prior were retrieved from files, and alternate cases were scanned at original magnification of ×20. Each pathologist reviewed his or her cases using either a microscope or imaging application. Independent pathologists identified and classified discrepancies; an independent statistician calculated major and minor discrepancy rates for both WSI and microscope slide review of the previously interpreted cases.

RESULTS

The 607 cases reviewed reflected the subspecialty interests of the 2 pathologists. Study limitations include the lack of cytopathology, hematopathology, or lymphoid cases; the case mix was not enriched with difficult cases; and both pathologists had interpreted several hundred WSI cases before the study to minimize the learning curve. The major and minor discrepancy rates for WSI were 1.65% and 2.31%, whereas rates for microscope slide reviews were 0.99% and 4.93%.

CONCLUSIONS

Based on our assumptions and study design, diagnostic review by WSI was not inferior to microscope slide review (P < .001).

Concordance between whole-slide imaging and light microscopy for routine surgical pathology

The use of high-resolution digital images of histopathology slides as a routine diagnostic tool for surgical pathology was investigated. The study purpose was to determine the diagnostic concordance between pathologic interpretations using whole-slide imaging and standard light microscopy. Two hundred fifty-one consecutive surgical pathology cases (312 parts, 1085 slides) from a single pathology service were included in the study after cases had been signed out and reports generated. A broad array of diagnostic challenges and tissue sources were represented, including 52 neoplastic cases. All cases were digitized at ×20 and presented to 2 pathologists for diagnosis using whole-slide imaging as the sole diagnostic tool. Diagnoses rendered by the whole-slide imaging pathologists were compared with the original light microscopy diagnoses. Overall concordance between whole-slide imaging and light microscopy as determined by a third pathologist and jury panel was 96.5% (95% confidence interval, 94.8%-98.3%). Concordance between whole-slide imaging pathologists was 97.7% (95% confidence interval, 94.7%-99.2%). Five cases were discordant between the whole-slide imaging diagnosis and the original light microscopy diagnosis, of which 2 were clinically significant. Discordance resulted from interpretive criteria or diagnostic error. The whole-slide imaging modality did not contribute to diagnostic differences. Problems encountered by the whole-slide imaging pathologists primarily involved the inability to clearly visualize nuclear detail or microscopic organisms. Technical difficulties associated with image scanning required at least 1 slide be rescanned in 13% of the cases. Technical and operational issues associated with whole-slide imaging scanning devices used in this study were found to be the most significant obstacle to the use of whole-slide imaging in general surgical pathology.

High-throughput profiling of tissue and tissue model microarrays: Combined transmitted light and 3-color fluorescence digital pathology

For many years pathologists have used Hematoxylin and Eosin (H&E), single marker immunohistochemistry (IHC) and in situ hybridization with manual analysis by microscopy or at best simple digital imaging. There is a growing trend to update pathology to a digital workflow to improve objectivity and productivity, as has been done in radiology. There is also a need for tissue-based multivariate biomarker assays to improve the accuracy of diagnostic, prognostic, and predictive testing. Multivariate tests are not compatible with the traditional single marker, manual analysis pathology methods but instead require a digital platform with brightfield and fluorescence imaging, quantitative image analysis, and informatics. Here we describe the use of the Hamamatsu NanoZoomer Digital Pathology slide scanner with HCImage software for combined brightfield and multiplexed fluorescence biomarker analysis and highlight its applications in biomarker research and pathology testing. This combined approach will be an important aid to pathologists in making critical diagnoses.

Use of a laboratory information system driven tool for pre-signout quality assurance of random cytopathology reports

BACKGROUND

Quality assurance (QA) programs in cytopathology laboratories in the USA currently primarily involve the review of Pap tests per clinical laboratory improvement amendments of 1988 federal regulations. A pre-signout quality assurance tool (PQAT) at our institution allows the laboratory information system (LIS) to also automatically and randomly select an adjustable percentage of non-gynecological cytopathology cases for review before release of the final report. The aim of this study was to review our experience and the effectiveness of this novel PQAT tool in cytology.

MATERIALS AND METHODS

Software modifications in the existing LIS application (CoPathPlus, Cerner) allow for the random QA of 8% of cases prior to signout. Selected cases are assigned to a second QA cytopathologist for review and all agreement and disagreements tracked. Detected errors are rectified before the case is signed out. Data from cases selected for PQAT over an 18-month period were collected and analyzed.

RESULTS

The total number of non-gynecological cases selected for QA review was 1339 (7.45%) out of 17,967 cases signed out during this time period. Most (1304) cases (97.4%) had an agreement in diagnosis. In 2.6% of cases, there were disagreements, including 34 minor and only 1 major disagreement. Average turnaround time of cases selected for review was not significantly altered.

CONCLUSION

The PQAT provides a prospective QA mechanism in non-gynecological cytopathology to prevent diagnostic errors from occurring. This LIS-driven tool allows for peer review and corrective action to be taken prior to reporting without delaying turnaround time, thereby improving patient safety.

Computer-aided identification of prostatic adenocarcinoma: Segmentation of glandular structures

Background:

Identification of individual prostatic glandular structures is an important prerequisite to quantitative histological analysis of prostate cancer with the aid of a computer. We have developed a computer method to segment individual glandular units and to extract quantitative image features, for computer identification of prostatic adenocarcinoma.

Methods:

Two sets of digital histology images were used: database I (n = 57) for developing and testing the computer technique, and database II (n = 116) for independent validation. The segmentation technique was based on a k-means clustering and a region-growing method. Computer segmentation results were evaluated subjectively and also compared quantitatively against manual gland outlines, using the Jaccard similarity measure. Quantitative features that were extracted from the computer segmentation results include average gland size, spatial gland density, and average gland circularity. Linear discriminant analysis (LDA) was used to combine quantitative image features. Classification performance was evaluated with receiver operating characteristic (ROC) analysis and the area under the ROC curve (AUC).

Results:

Jaccard similarity coefficients between computer segmentation and manual outlines of individual glands were between 0.63 and 0.72 for non-cancer and between 0.48 and 0.54 for malignant glands, respectively, similar to an interobserver agreement of 0.79 for non-cancer and 0.75 for malignant glands, respectively. The AUC value for the features of average gland size and gland density combined via LDA was 0.91 for database I and 0.96 for database II.

Conclusions:

Using a computer, we are able to delineate individual prostatic glands automatically and identify prostatic adenocarcinoma accurately, based on the quantitative image features extracted from computer-segmented glandular structures.

Pathology Review of Outside Material: When Does It Help and When Can It Hurt?

Purpose

Pathology review is performed for patients when care is transferred to a tertiary care center after diagnostic tissue has been obtained. While it has many benefits, this practice can lead to unforeseen difficulties in doctor-patient communication and patient well-being, especially if a diagnosis is overturned or modified years after treatment. The aim of this analysis is to identify clinical situations in which pathology review can result in challenging discussions between patients and oncologists.

Patients

Representative case scenarios are presented in the subspecialty area of hematopathology. Analysis of the clinical benefits and possible harm to patients, pathologists, and treating oncologists that may ensue from pathology review is performed.

Results

Pathology review may result in a valuable second opinion and expert subclassification. However, problematic situations may arise with pathology review, especially if the patient has already undergone definitive treatment and is referred to an academic institution in remission. Difficulties can also arise when patients do not understand the limitations of diagnosing disease on small biopsies. The patient may receive a different diagnosis or it may become apparent that the diagnosis could have been made more expeditiously. These discrepancies must be communicated to the patient and may cause confusion and distress.

Conclusion

Pathology review can be beneficial or potentially harmful depending on the clinical situation. Preliminary recommendations are provided for selecting patients for review. Limiting pathology review to certain clinical situations and encouraging patients to get second opinions before initial treatment at local referral centers may be helpful in minimizing reassignment of diagnoses after definitive treatment.

Clinical examination and validation of primary diagnosis in anatomic pathology using whole slide digital images

CONTEXT

Novel anatomic pathology technologies allow pathologists to digitally view and diagnose cases. Although digital pathology advocates champion its strengths and move to integrate it into practice and workflow, the capabilities and limitations of digital slides have not been fully investigated.

OBJECTIVES

To estimate intrapathologist diagnostic discrepancy between glass and digital slides and to determine pathologists' diagnostic certainty when diagnosing with the 2 formats.

DESIGN

Intrapathologist diagnostic consistency between glass and digital slides was measured. Three pathologists diagnosed 101 cases digitally and with corresponding glass slides. Discrepancies between formats were evaluated, and diagnostic precision and certainty were compared.

RESULTS

A total of 606 diagnoses were evaluated in pairs (202 per pathologist). Seven cases did not transfer to the database and were eliminated from further study. We report no discrepancies between media in 75%, 87%, and 83% of the cases diagnosed by the 3 pathologists, respectively; significant discrepancies were identified in 3%, 3%, and 7% of cases by each pathologist. In total, we identified significant clinical and therapeutic discrepancies in 13 of 296 cases (4.4%). The certainty values provided by each pathologist were similar between formats.

CONCLUSIONS

This study did not detect significant differences between diagnoses based on digital and glass slides. We believe that this study further supports the integration of digital slides into pathology workflow, particularly considering the low rate of discrepancy documented here.

One hundred consecutive granulomas in a pulmonary pathology consultation practice

Lung biopsies showing granulomatous disease are commonly sent for expert pathology consultation. On the basis of features we and others have identified, an algorithmic approach to diagnosis of these cases was developed. We hypothesized that applying this approach would increase the likelihood of rendering a more specific diagnosis, or by rendering either a narrower or broader differential diagnosis, offer a more clinically useful diagnosis. One hundred consecutive lung biopsies from patients with granulomatous and giant cell reactions were retrieved from our consultation files. Cases were categorized into those in which a confident diagnosis was made at sign out, ones in which a specific diagnosis was strongly favored, and those in which a differential diagnosis was suggested. One year later follow-up information was obtained and consultation diagnoses were compared with clinical diagnoses to determine the reliability of the approach. A confident diagnosis was rendered in 27 cases, a specific diagnosis was strongly favored in 34, and in 39 a differential diagnosis was provided. Consultant diagnoses were more specific in 47 of 75 (63 %) cases. In 15 cases, the differential diagnosis was expanded. The most common unrecognized diagnosis was aspiration pneumonia and the most common diagnosis omitted from the differential diagnosis by the primary pathologist was hypersensitivity pneumonia. Follow-up in 49% of cases in which it was sought, confirmed the consultant's diagnosis or was inconclusive in 97% of cases. The use of a standardized algorithmic approach to the interpretation of granulomatous disease in lung biopsies yields more specific and clinically useful diagnoses for consideration.

The development and testing of a laboratory information system-driven tool for pre-sign-out quality assurance of random surgical pathology reports

We describe the development and testing of a novel pre-sign-out quality assurance tool for case diagnoses that allows for the random review of a percentage of cases by a second pathologist before case verification and release of the final report. The tool incorporates the ability to record and report levels of diagnostic disagreement, reviewers' comments, and steps taken to resolve any discrepancies identified. It is expandable to allow for the review of any percentage of cases in any number of subspecialty or general pathology "benches" and provides a prospective instrument for preventing some serious errors from occurring, thereby potentially affecting patient care in addition to identifying and documenting more general process issues. It can also be used to augment other more conventional methods of quality control such as frozen section/final diagnosis correlation, conference review, and case review before interdisciplinary clinicopathologic sessions. There has been no significant delay in case turnaround time since implementation. Further assessment of the tool's function after full departmental application is underway.

Interinstitutional consultation in fine-needle aspiration cytopathology: a study of 742 cases

BACKGROUND

The importance of interinstitutional consultation (IC) has been documented across a variety of surgical pathology organ systems. However, to the authors' knowledge, few studies exist regarding this practice within cytopathology and specifically within fine-needle aspiration cytology (FNAC).

METHODS

All FNAC cases between September 2002 and January 2007 were reviewed. Original diagnoses and second opinion diagnoses (SODs) were categorized as either no diagnostic disagreement, or minor diagnostic disagreement, or major diagnostic disagreement, and the latter was defined as either a 2-step deviation on a scale of "unsatisfactory, benign, atypical, suspicious, and malignant" or a change in treatment and/or prognosis. Outcome was determined by a review of the electronic medical record.

RESULTS

Among 742 FNAC cases from outside laboratories, there were minor disagreements in 132 cases (17.8%) and major disagreements in 69 cases (9.3%) compared with the SODs from the authors' laboratory. Follow-up was available for 60 of 69 major discrepancies. The SOD was supported on follow-up in 65% of major discrepancies, and the initial diagnosis was supported better in 33% of major discrepancies. In 55% of cases in which the original institution diagnosis was supported better, either no case slides were received for examination or the slides contained material that was considered nondiagnostic by the authors. An SOD prompted a change in clinical management in 32 of 742 patients (4.3%). Aspirates that were most prone to change in management or therapy were from the thyroid (13 cases), neck (soft tissue and lymph nodes; 9 cases), salivary gland (2 cases), and liver (2 cases). Of 60 major diagnostic disagreements, board-certified cytopathologists rendered an SOD in 44 cases, and 75% of the diagnoses were supported better by follow-up, whereas pathologists who were not board certified in cytopathology had only 38% of SODs supported.

CONCLUSIONS

Of 742 FNAC cases, 9.3% had major diagnostic disagreements; and, in 4.3%, patient management and therapy were altered. These results were similar to studies in surgical pathology emphasizing the importance of IC in FNAC. The authors concluded that FNAC IC benefits patient care.

Medicolegal issues in pathology

The various methods used by risk managers to assist clinicians in handling medicolegal risk, including improving communication with patients and better dealing with medical records issues, are not particularly of benefit to pathologists. An understanding of tort law, the theory of negligence, the principle of standard of care, and the role of the expert witness helps the pathologist generally assess and manage risk and put it into context with daily pathology practice. An understanding of the litigation process and techniques to better handle a deposition and high-risk specimens or diagnoses are of practical value in avoiding a lawsuit or increasing the likelihood for good outcome in medical malpractice litigation.

Spatial resolution requirements for acquisition of the virtual screening slide for digital whole-specimen breast histopathology

We examined the effect of lateral spatial resolution and reader specialty on the accuracy of detection of breast cancer. The motivation for this pilot study was the need to acquire and display very large data sets in whole-specimen 3D digital breast histopathology imaging. The ultimate goal is to determine the minimum resolution adequate for detection of malignancy. Twenty-three histologic slides were selected from breast pathology cases and digitized at 2 sampling distances (3.2 and 1.9 microm pixels). Images were viewed by 14 pathologists, of whom 5 had breast pathology as their primary specialty. The readers assessed the likelihood of malignancy on a 5-point Likert scale, and provided a provisional diagnosis. For the detection task, sensitivity, specificity, overall accuracy of detection, and area under the receiver-operator curve were calculated. An overall diagnostic score, and scores grouped by malignancy type, were also computed. Outcome measures were examined for significant resolution and specialty effects. Increasing the lateral resolution significantly improved accuracy in diagnosis (P=.004) but no effect was found for detection. Breast specialists achieved significantly higher scores for all outcome measures except specificity. Differences in performance between the 2 groups of readers tended to be greater for the diagnostic task compared to detection, especially at the higher resolution. However, specimen coverage may also be a significant factor. Factors related to the readers may have also affected performance in this study. Based on these results, a more comprehensive study should examine pixel sizes between 0.7 and 1.9 microm.

Medicolegal liability in surgical pathology: a consideration of underlying causes and selected pertinent concepts

Malpractice actions against surgical pathologists are still relatively uncommon, but they have increased in frequency over time and are associated with sizable indemnity figures. This discussion categorizes areas of liability in surgical pathology into three groups: those that represent health system flaws (problems with specimen identification, or transportation, or both; lack of clinical information or erroneous information; sampling effects and defects; and poorly reproducible or poorly defined diagnostic or prognostic criteria), others that exist at the interface between the system and individuals (allowing clinicians to bypass pathologic review of referred specimens; acceding to clinical demands for inadvisable procedures; and working in a disruptive environment), and truly individual errors by pathologists (lapses in reasoning; deficiencies concerning continuity in the laboratory; invalid assumptions regarding recipients of surgical pathology reports; over-reliance on the results of "special" tests; and problems with peer consultation). Finally, two important topic areas are discussed that commonly enter into lawsuits filed against surgical pathologists; namely, "delay in diagnosis" of malignant neoplasms and "failure to provide adequate prognostic information." Based on a review of the pertinent literature, we conclude that the clinical courses of most common malignancies are not affected in a significant manner by delays in diagnosis. Moreover, the practice of using "personalized external validity" for supposedly prognostic tests is examined, with the resulting opinion that prognostication of tumor behavior in individual patients is not reliable using anything but anatomic staging systems.

Diagnostic ‘errors’ in anatomical pathology: relevance to Australian laboratories

Failure to recognise that anatomical pathology diagnosis is a process of cognitive interpretation of the morphological features present in a small tissue sample has led to the public misperception that the process is infallible. The absence of a universally accepted definition of diagnostic error makes comparison of error rates impossible and one large study of laboratories in the United States shows a significant error rate of about 5%, most of which have no major impact on patient management. A recent review of the work of one pathologist in New South Wales confirms a lack of appreciation in medical administration that variable diagnostic thresholds result in an inherent fallibility of anatomical pathology diagnoses. The outcome of the review emphasises the need to educate both public and non-pathology colleagues of the nature of our work and brings into consideration the requirement to establish baseline error rates for Australian laboratories and the role of the Royal College of Pathologists of Australasia (RCPA) in developing fair and unbiased protocols for review of diagnostic errors. The responsibility of ensuring that diagnostic error rates are kept to the minimum is a shared one. Area health services must play their part by seeking to ensure that pathologists in any laboratory are not overworked and have adequate support and back-up from pathologists with expertise in specialised areas. It has been clearly enunciated by the Royal College of Pathologists in the United Kingdom that it is not safe for any histopathology service to be operated single-handedly by one histopathologist. Service managers and clinicians have to understand that country pathologists cannot provide the full range and depth of pathology expertise in the many clinical subspecialty areas that are often practised in non-metropolitan areas. Attending clinicians share the responsibility of accepting proffered pathology diagnoses only if it conforms to the clinical context. Pathology laboratories must continue to develop and maintain best-practice protocols and conduct periodic reviews of diagnosis, cytology-histology concordance, frozen section/permanent section correlations, conference reviews, intra and interdepartmental consultations, participate in external quality assurance programs and maintain ongoing education for all laboratory staff.