Errors in histopathology reporting: detection and avoidance

Evaluation of Turnaround Times of Diagnostic Biopsies: A Metric of Quality in Surgical Pathology

Introduction. Timely and accurate diagnosis of diseases is crucial for effective patient care. Turnaround time (TAT) in surgical pathology, defined as the time between accessioning the sample and reporting results, is a key performance indicator reflecting quality and efficiency. This study explores factors affecting TAT for diagnostic biopsies in a tertiary oncology hospital. Methods. A 1-month pilot study was conducted, focusing on 695 in-house diagnostic biopsies. Biopsies were categorized as routine (requiring only hematoxylin and eosin (H&E) staining) or complex cases (requiring additional tests). TAT was defined as the time between sample accessioning and report availability in the electronic medical record, with delays defined as exceeding 3 days for routine cases and 4 days for complex cases. Survival analysis using Kaplan-Meier plots was utilized to analyze TAT. Results. The overall mean TAT was 3.7 ± 2 days, with routine cases at 3.1 ± 2 days and complex cases at 4.8 ± 2 days (P < 0.001). Survival analysis revealed prolonged TAT for complex cases. Organ-specific analysis highlighted variations in TAT, with brain biopsies presenting the highest complexity and longest TAT. Surprisingly, malignant cases demonstrated slightly shorter TATs compared to benign cases (P = 0.026). Delays were observed in 34% of all cases. Conclusions. Laboratory TAT is crucial and is frequently used as a performance benchmark. We analyzed the various causes of delayed TAT in our hospital's histopathology department, with an emphasis on variables in the analytical phase. The results of this study demonstrate that cases involving ancillary techniques had significantly longer TATs compared to routine H&E cases.

Deep Learning for Subtypes Identification of Pure Seminoma of the Testis

The most critical step in the clinical diagnosis workflow is the pathological evaluation of each tumor sample. Deep learning is a powerful approach that is widely used to enhance diagnostic accuracy and streamline the diagnosis process. In our previous study using omics data, we identified 2 distinct subtypes of pure seminoma. Seminoma is the most common histological type of testicular germ cell tumors (TGCTs). Here we developed a deep learning decision making tool for the identification of seminoma subtypes using histopathological slides. We used all available slides for pure seminoma samples from The Cancer Genome Atlas (TCGA). The developed model showed an area under the ROC curve of 0.896. Our model not only confirms the presence of 2 distinct subtypes within pure seminoma but also unveils the presence of morphological differences between them that are imperceptible to the human eye.

Kidney Pathology Education for Nephrology Fellows: Past, Present, and Future

Kidney pathology education is a critical component in training of nephrology fellows, as well as for continuing medical education for practicing nephrologists. Kidney pathology images are included on nephrology fellow board exams, and clinicopathologic correlation of kidney biopsy findings is critical in everyday clinical practice. Nephropathology training is a requirement by the American College of Graduate Medical Education within nephrology fellowship curricula. However, greater than one-third of fellowship program directors believe that nephropathology training for their fellows is not sufficient. During the Coronavirus Disease-19 pandemic, the use of digital learning has become commonplace with virtual conferences (local, national, and international) and online meetings becoming the norm for education. Nephrology has become a leader in free open-access online medical education, both prior to and, to even a greater extent, during the pandemic. Here, we review available resources to nephrology fellows and other learners to supplement nephropathology training, which includes medical blogs, journal clubs, interactive quizzes and games, online conferences, podcasts, and mentorship opportunities. These resources are archived and provide durable content to learners of all stages of training, even beyond the pandemic.

Standardization of Manual Method of Immunohistochemical Staining for Breast Cancer Biomarkers at Tertiary Cancer Care Center: An Audit

Immunohistochemistry (IHC) is a necessary ancillary technique in surgical pathology laboratories, particularly for oncology tissue specimens. Automation in the IHC technique has an advantage over manual methods in terms of quality, except for the cost of the equipment. Thus, the manual method of IHC staining is the preferred method of choice in countries with limited resources. However, standardization of all steps in the preanalytic phase is critical to obtain reliable immunohistochemistry test results. The current audit was conducted to describe the preanalytic factors affecting manual IHC methods. The most important preanalytic factors were fixative, the composition of dehydrate, pH, drying of sections, and heat-mediated antigen retrieval method (HMAR). The domestic pressure cooker method was found to be the best for HMAR.

Convolutional Neural Network Based Breast Cancer Histopathology Image Classification

Breast cancer is a global health concern, with approximately 30 million new cases projected to be reported by 2030. While efforts are being channeled into curative measures, preventive and diagnostic measures also need to be improved to curb the situation. Convolutional Neural Networks (CNNs) are a class of deep learning algorithms that have been widely adopted for the computerized classification of breast cancer histopathology images. In this work, we propose a set of training techniques to improve the performance of CNN-based classifiers for breast cancer identification. We combined transfer learning techniques with data augmentation and whole image training to improve the performance of the CNN classifier. Instead of conventional image patch extraction for training and testing, we employed a high-resolution whole-image training and testing on a modified network that was pre-trained on the Imagenet dataset. Despite the computational complexity, our proposed classifier achieved significant improvement over the previously reported studies on the open-source BreakHis dataset, with an average image level accuracy of about 91% and patient scores as high as 95%.Clinical Relevance- this work improves on the performance of CNN for breast cancer histopathology image classification. An improved Breast cancer image classification can be used for the preliminary examination of tissue slides in breast cancer diagnosis.

Nondiagnostic fine-needle aspirates of the pancreas: A root cause analysis

BACKGROUND

Fine-needle aspiration (FNA) of the pancreas is considered the primary and least invasive diagnostic method in the evaluation of pancreatic lesions. A nondiagnostic sample may trigger repeat FNA or a more invasive diagnostic procedure. The goal of this study was to identify the root causes of nondiagnostic samples.

METHODS

We performed a retrospective review of FNAs of the pancreas categorized as nondiagnostic at our institution between 2008 and 2019. Medical records and slides were reviewed to identify the features described by imaging, rapid on-site evaluation, fluid chemistry, final cytology diagnosis, and final histology. A root cause analysis was performed using the Ishikawa (or fishbone) diagram and the 5 Whys method.

RESULTS

A total of 30 cases were identified: 11 adenocarcinomas, 6 cases of pancreatitis, 4 intraductal papillary mucinous neoplasms, 3 serous cystadenomas, 3 neuroendocrine tumors, 1 mucinous cystic neoplasm, 1 retention cyst, and 1 case of Brunner gland hyperplasia. The root causes identified were: man in 8 cases, machine in 1 case, method in 17 cases, and material in 18 cases. In many cases, more than 1 root cause contributed to the problem.

CONCLUSION

Material related errors contributed to the majority of nondiagnostic results and were primarily related to fibrotic cancers, chronic pancreatitis, absence of diagnostic criteria of cystic lesions, and technically challenging cases. Only 1 major interpretation error was identified. Sampling and interpretive errors contributed equally to man-related causes. For mucinous cysts, neoplastic mucin was difficult to identify in liquid-based preparations. Pathologists tended to issue a nondiagnostic categorization when epithelial cells are lacking and particularly when the nature and radiological impression of the cyst was not communicated.

Pathological review of primary cutaneous malignant melanoma by a specialist skin cancer multidisciplinary team improves patient care in the UK

AIMS

The National Institute for Health and Care Excellence advocated the development of specialist skin cancer multidisciplinary teams (SSMDTs) for the management of higher risk invasive skin cancers in the UK. The interobserver variability in the histopathological assessment of primary cutaneous malignant melanoma (PCMM) is well recognised.

METHODS

We evaluated the discordance rates in the assessment of the histopathological criteria of PCMM based on the eighth American Joint Committee on Cancer (AJCC) melanoma staging system and subsequent change in prognosis and management following pathology review by an SSMDT.

RESULTS

353 cases of PCMM were referred to our SSMDT between April 2015 and May 2016. Cases in which there was a discrepancy in one or more histological parameters following expert review were collected retrospectively. Of 341 eligible cases, there were 94 (27.6%) in which there was an alteration in any parameter. There was interobserver agreement in final diagnosis in 96.8%, Breslow thickness in 86.8%, ulceration in 98.2%, microsatellites in 98.5%, tumour mitotic rate in 88.9%, histological subtype in 92.4%, growth phase in 98.5%, angiolymphatic invasion in 97.7%, perineural invasion in 98.8%, regression in 95.3% and tumour-infiltrating lymphocytes in 95.0%. A corresponding change in AJCC stage occurred in 23 cases (6.7%), with a resulting change in clinical management in 10 cases (2.9%).

CONCLUSIONS

Disagreements in the pathological assessment of PCMM can have significant clinical implications for a small number of patients. Our findings highlight the value of the SSMDT for high-quality care of patients with melanoma in the UK.

Quality and safety aspects in histopathology laboratory

Histopathology is an art of analyzing and interpreting the shapes, sizes and architectural patterns of cells and tissues within a given specific clinical background and a science by which the image is placed in the context of knowledge of pathobiology, to arrive at an accurate diagnosis. To function effectively and safely, all the procedures and activities of histopathology laboratory should be evaluated and monitored accurately. In histopathology laboratory, the concept of quality control is applicable to pre-analytical, analytical and post-analytical activities. Ensuring safety of working personnel as well as environment is also highly important. Safety issues that may come up in a histopathology lab are primarily those related to potentially hazardous chemicals, biohazardous materials, accidents linked to the equipment and instrumentation employed and general risks from electrical and fire hazards. This article discusses quality management system which can ensure quality performance in histopathology laboratory. The hazards in pathology laboratories and practical safety measures aimed at controlling the dangers are also discussed with the objective of promoting safety consciousness and the practice of laboratory safety.

Look back and talk openly: responding to and communicating about the risk of large-scale error in pathology diagnoses

QUALITY PROBLEM OR ISSUE

In 2005 we were informed about the possibility of a systemic error in pathology diagnoses of ~7400 histological tests done between 4 and 6 years earlier.

INITIAL ASSESSMENT

We determined to undertake a lookback and apply principles of open disclosure to inform the affected community of ~200,000 people.

CHOICE OF SOLUTION

The lookback included subjecting all cases to independent pathology review. The public announcement of the review included an unreserved apology and took place before the results of the re-examination of the pathology specimens were known.

IMPLEMENTATION

The lookback involved the simultaneous implementation of five critical elements: leadership and governance, risk assessment and planning, implementation of the independent review, procedures for patient care and communication and open disclosure. Protocols were developed to care for those patients whose original test results were found to be incorrect.

EVALUATION

The original result for >200 patients was incorrect, and 38 had experienced clinical consequences. There was no public panic as a result of the wide open disclosure. Few related legal claims or complaints were made. The impact of the pathology diagnostic error has continued to 2011 for some patients.

LESSONS LEARNED

Openly disclosing a risk of widespread error meant the community could be supported with information and medical management as needed. Credentialing and peer-review processes for senior staff must be precise and collegiate. Sometimes action has to take place even when the risk is ill defined. There are five critical elements in planning and implementing a large-scale lookback.

Intra-operative frozen section analysis for suspected early-stage ovarian cancer: 11 years of Gateshead Cancer Centre experience

OBJECTIVE

In centres in which intra-operative frozen section (FS) analysis is not performed, 'apparent' early-stage ovarian cancer diagnosed after surgery on paraffin section may require further restaging laparotomy or adjuvant chemotherapy. Previous studies on FS analysis have reported high sensitivity, specificity and overall accuracy. The objective of this article is to present the largest published dataset on the accuracy of FS analysis over an 11-year period from a single institution.

DESIGN

Diagnostic test accuracy.

SETTING

Northern Gynaecological Oncology Centre and Department of Cellular Pathology, Gateshead, UK.

POPULATION

1439 intra-operative FS analyses performed between January 2000 and December 2010 for suspected ovarian cancer.

METHODS

Prospectively collected data on FS analysis were compared with gold standard paraffin section.

MAIN OUTCOME MEASURES

Sensitivity, specificity, likelihood ratios and post-test probability.

RESULTS

The overall sensitivity and specificity of FS analysis were 91.2% and 98.6%, respectively. Positive and negative likelihood ratios were 64.7% and 0.09%, respectively. The pre-test probability of an ovarian tumour being borderline or malignant was 45.8%. When FS analysis was reported to be positive, the post-test probability increased to 98% (confidence interval, 97-99%). Conversely, when FS analysis was reported to be negative, the post-test probability decreased to 7% (confidence interval, 6-9%). The majority of false test results were either borderline tumours or of mucinous differentiation.

CONCLUSIONS

Intra-operative FS analysis has excellent diagnostic test accuracy and assists gynaecological oncologists to perform the appropriate surgery in 95% of cases, thereby preventing the morbidity of surgical staging in benign cases and the morbidity of restaging procedures or chemotherapy in early-stage malignant tumours.

Experts and performance in histopathology--a study in breast pathology

This study was undertaken to determine if it was possible to identify expertise within Histopathologists (trainees, district general pathologists and pathologists with a special interest in breast disease) using an objective measure of performance. The method of assessment of performance is based on the CWS (Cochran-Weiss-Shanteau) ratio formed by the individual's ability to discriminate between a spectrum of disease categories and their level of inconsistency when assessed at intervals. The slides circulated represented the spectrum of breast disease seen in routine practice. The results demonstrated the average CWS ratio to be lowest in trainees and highest in pathologists with a special interest in breast pathology although there was no statistical difference in the CWS scores obtained between the district general pathologists and pathologists with a special interest. Differences in inconsistency rather than discriminatory ability mainly accounted for the difference in the CWS ratio observed between the groups studied. The study shows that the CWS ratio is potentially a very useful tool in the assessment of pathologists with regard to assessing their progress through training.

Quality of pathology reports for advanced ovarian cancer: are we missing essential information? An audit of 479 pathology reports from the EORTC-GCG 55971/NCIC-CTG OV13 neoadjuvant trial

OBJECTIVE

To assess the quality of surgical pathology reports of advanced stage ovarian, fallopian tube and primary peritoneal cancer. This quality assurance project was performed within the EORTC-GCG 55971/NCIC-CTG OV13 study comparing primary debulking surgery followed by chemotherapy with neoadjuvant chemotherapy and interval debulking surgery.

METHODS

Four hundred and seventy nine pathology reports from 40 institutions in 11 different countries were checked for the following quality indicators: macroscopic description of all specimens, measuring and weighing of major specimens, description of tumour origin and differentiation.

RESULTS

All specimens were macroscopically described in 92.3% of the reports. All major samples were measured and weighed in 59.9% of the reports. A description of the origin of the tumour was missing in 20.5% of reports of the primary debulking group and in 23.4% of the interval debulking group. Assessment of tumour differentiation was missing in 10% of the reports after primary debulking and in 20.8% of the reports after interval debulking. Completeness of reports is positively correlated with accrual volume and adversely with hospital volume or type of hospital (academic versus non-academic). Quality of reports differs significantly by country.

CONCLUSION

This audit of ovarian cancer pathology reports reveals that in a substantial number of reports basic pathologic data are missing, with possible adverse consequences for the quality of cancer care. Specialisation by pathologists and the use of standardised synoptic reports can lead to improved quality of reporting. Further research is needed to better define pre- and post-operative diagnostic criteria for ovarian cancer treated with neoadjuvant chemotherapy.

Detection and classification of diagnostic discrepancies (errors) in surgical pathology

Detecting and classifying error in a surgical pathology (SP) practice is an important part of a comprehensive quality assurance program. There are a number of mechanisms to detect error, including secondary review, examination of amended reports, correlation studies (cytology-histology and frozen-final diagnosis correlation). These different detection methods are reviewed in this paper. Additionally, the most common methods for error classification are also reviewed, along with the benefits and limitations of each. Although there is presently no gold standard for detecting or classifying errors in SP, based on this review of the literature, it is clearly good practice to consistently apply a standard method. Most importantly, these data should be incorporated into quality assurance and quality improvement activities, such that departments strive to reduce errors, and to help improve overall quality in SP.

Contamination of histology biopsy specimen - a potential source of error for surgeons: a case report

Tissue contamination is a common occurrence in pathology, but surgeons are relatively unaware of this. We present the case of a 45-year-old man with Barrett's oesophagus, in which the histology of routine biopsies of an asymptomatic patient, were reported as 'carcinoma in situ'. Further biopsies were taken over a three month period but showed no evidence of malignancy. Tissue contamination or 'cross over' was identified as the likely cause of the abnormal result. This case report highlights the importance of the correlation of the clinical and histopathological findings and tissue contamination should be considered when both of these findings are not consistent.

An active pixel sensor x-ray diffraction (APXRD) system for breast cancer diagnosis

This paper describes the potential application of an active pixel sensor-based x-ray diffraction (APXRD) system in the field of breast cancer diagnosis. The design and initial testing of the system was reported previously (Bohndiek et al 2008b Phys. Med. Biol. 53 655-72). The system has potential both as a 'diffraction enhanced breast imager' (DEBI) and as a probe for quantitative analysis of breast biopsy samples. The resolution of the system in a DEBI arrangement is 1 mm and the contrast available using a material-specific x-ray diffraction image was found to be up to seven times greater than that of a transmission image. Scatter signatures from a series of biopsy-equivalent samples, ranging in composition from 100% fat to 100% fibrous tissue, were acquired with the APXRD system. Multivariate data analysis was used to produce a partial least squares (PLS) model sensitive to sample fat content. The final model is able to accurately predict the fat content of a series of unknown samples and is robust to significant added noise. This suggests that the APXRD system could provide a simple, semi-automated, quantitative measurement system for analysis of breast biopsy samples. Training on a range of scatter signatures from real breast biopsy samples covering various stages of disease is now needed to test this hypothesis.

[Internal quality control of histological diagnosis in pathology. A nine-year experience]

Internal quality control (IQC) is a necessary component of total quality management. We report our experience with an internal audit scheme focusing on the histological diagnosis. We outline other strategies of IQC and analyze the causes of errors and ways to prevent them. Some practical guidelines to initiate this type of procedure are presented. Our audit was designed to check the accuracy of diagnosis, the clarity and completeness of the report, the quality of the documents leading to the diagnosis, and the turn-around time. It consisted of a retrospective analysis of 4185 randomly selected cases (representing 2% of all cases), over nine years. The control took place once a week and was done by two pathologists working as a team. The mean time spent by each pathologist was 45 minutes per week. Errors were scored using a 3-level grading scheme depending on their potential harm or impact on patient care. The overall rate of errors was 1.1%, and 0.1% of errors were potentially harmful to the patients. A single case (0.02%), in which a cancer was missed, had a real impact on patient care. Retrospective analysis of randomly selected cases mirrors the overall activity of a surgical pathology department. Nevertheless, each lab has to develop its own strategy of IQC, based on its size, its functioning, and its objectives. Although it may be difficult to initiate quality assurance when medical time is already limited, it is a helpful procedure in a more and more demanding medical and societal context and a pragmatic step towards "culture of quality".

Misinterpretation of histopathological results as an important risk factor for unneeded surgery - case report of a "near miss" event in a pregnant woman

The oral cavity may exhibit a vast number of pathologic conditions, often dealt with by different medical disciplines. Combined with a substantial variation in clinical appearance, an accurate diagnosis may provide difficult to establish in selected cases. Histopathological investigations are therefore mandatory for correct diagnosis and adequate treatment. We describe a common, truly benign condition in the oral cavity, which due to histopathological misinterpretation was planned for major surgery and subsequent chemotherapy. This was avoided by spontaneous regression of the lesion. The case illustrates that uncritical trust in laboratory diagnostic tests may lead to severe mistreatment.

Agreement among surgical pathologists evaluating routine histologic sections of digits amputated from cats and dogs

Agreement among pathologists interpreting histologic specimens is an area of interest within human pathology, but little work in this area has been reported in the veterinary literature. Agreement among pathologists evaluating routine histologic sections of amputated digits from cats and dogs submitted to multiple diagnostic centers was examined. Histologic sections from surgical specimens were reviewed in a blinded fashion by two pathologists, and a comparison to the original diagnosis, as stated in the diagnostic report, was recorded. A total of 513 cases were reviewed, and complete agreement was reached in 409 (79.7%). Of the 104 instances of disagreement, 77 (74.0%) were considered to be of clinical significance. The diagnosis of keratoacanthoma was disagreed with in 19 of 21 diagnoses (90.4%). No other individual diagnosis was similarly disputed. The overall level of disagreement is large and is similar to that reported in human pathology and suggests that further study of this issue would be useful in veterinary pathology.

The value of inking breast cores to reduce specimen mix-up

Accidental switching of tissue specimens in the histology laboratory can result in significant medical error. We sought to evaluate inking breast core needle specimens as a method to reduce the chance of specimen mix-up. We sequentially inked 1,000 consecutive breast core specimens with 6 different colors. Review of the color of the ink revealed 3 discrepancies: 1 related to blocks being switched, 1 related to incorrect labeling, and 1 was a typographical error. Inking of breast core specimens is a simple, inexpensive, and effective way to help reduce the chance of specimen mix-up.

Measuring errors in surgical pathology in real-life practice: defining what does and does not matter

This review summarizes our experience using blinded review as a method to measure quality in surgical pathology. It details the specifics about how the review is performed, the weaknesses in the method, and then summarizes our results so far. These results suggest that error rates correlate with the individual pathologist, the type of specimen, the type of diagnosis, subspecialization, and the number of pathologists who review a case. Errors do not correlate with workload. This method is relatively unbiased and effective at identifying significant errors in real life clinical practice. The drawback to this method is the amount of work involved. Blinded review, performed so that errors can be corrected in a timely manner, and eventually integrated into an interlaboratory review process, represents a realistic and fair method to provide quantitative quality assurance information.

Error reduction in surgical pathology

CONTEXT

Because of its complex nature, surgical pathology practice is inherently error prone. Currently, there is pressure to reduce errors in medicine, including pathology.

OBJECTIVE

To review factors that contribute to errors and to discuss error-reduction strategies.

DESIGN

Literature review.

RESULTS

Multiple factors contribute to errors in medicine, including variable input, complexity, inconsistency, tight coupling, human intervention, time constraints, and a hierarchical culture. Strategies that may reduce errors include reducing reliance on memory, improving information access, error-proofing processes, decreasing reliance on vigilance, standardizing tasks and language, reducing the number of handoffs, simplifying processes, adjusting work schedules and environment, providing adequate training, and placing the correct people in the correct jobs.

CONCLUSIONS

Surgical pathology is a complex system with ample opportunity for error. Significant error reduction is unlikely to occur without a sustained comprehensive program of quality control and quality assurance. Incremental adoption of information technology and automation along with improved training in patient safety and quality management can help reduce errors.

Patient safety in anatomic pathology: measuring discrepancy frequencies and causes

CONTEXT

Anatomic pathology discrepancy frequencies have not been rigorously studied.

OBJECTIVE

To determine the frequency of anatomic pathology discrepancies and the causes of these discrepancies.

DESIGN

Participants in the College of American Pathologists Q-Probes program self-reported the number of anatomic pathology discrepancies in their laboratories by prospectively performing secondary review (post-sign-out) of 100 surgical pathology or cytology specimens. Reasons for the secondary review included conferences, external review, internal quality assurance policy, and physician request.

PARTICIPANTS

Seventy-four laboratories self-reported data.

MAIN OUTCOME MEASURES

Frequency of anatomic pathology discrepancy; type of discrepancy (ie, change in margin status, change in diagnosis, change in patient information, or typographic error); effect of discrepancy on patient outcome (ie, no harm, near miss, or harm); and clarity of report.

RESULTS

The mean and median laboratory discrepancy frequencies were 6.7% and 5.1%, respectively. Forty-eight percent of all discrepancies were due to a change within the same category of interpretation (eg, 1 tumor type was changed to another tumor type). Twenty-one percent of all discrepancies were due to a change across categories of interpretation (eg, a benign diagnosis was changed to a malignant diagnosis). Although the majority of discrepancies had no effect on patient care, 5.3% had a moderate or marked effect on patient care.Conclusions.-This study establishes a mean multi-institutional discrepancy frequency (related to secondary review) of 6.7%.

Anatomic Pathology Databases and Patient Safety

Context.—The utility of anatomic pathology discrepancies has not been rigorously studied.

Objective.—To outline how databases may be used to study anatomic pathology patient safety.

Design.—The Agency for Healthcare Research and Quality funded the creation of a national anatomic pathology errors database to establish benchmarks for error frequency. The database is used to track more frequent errors and errors that result in more serious harm, in order to design quality improvement interventions intended to reduce these types of errors. In the first year of funding, 4 institutions (University of Pittsburgh, Henry Ford Hospital, University of Iowa, and Western Pennsylvania Hospital) reported cytologic-histologic correlation error data after standardizing correlation methods. Root cause analysis was performed to determine sources of error, and error reduction plans were implemented.

Participants.—Four institutions self-reported anatomic pathology error data.

Main Outcome Measures.—Frequency of cytologic-histologic correlation error, case type, cause of error (sampling or interpretation), and effect of error on patient outcome (ie, no harm, near miss, and harm).

Results.—The institutional gynecologic cytologic-histologic correlation error frequency ranged from 0.17% to 0.63%, using the denominator of all Papanicolaou tests. Based on the nongynecologic cytologic-histologic correlation data, the specimen sites with the highest discrepancy frequency (by project site) were lung (ranging from 16.5% to 62.3% of all errors) and urinary bladder (ranging from 4.4% to 25.0%). Most errors detected by the gynecologic cytologic-histologic correlation process were no-harm events (ranging from 10.7% to 43.2% by project site). Root cause analysis identified sources of error on both the clinical and pathology sides of the process, and error intervention programs are currently being implemented to improve patient safety.

Conclusions.—A multi-institutional anatomic pathology error database may be used to benchmark practices and target specific high-frequency errors or errors with high clinical impact. These error reduction programs have national import.

Standards, Options et Recommandations 2004 pour une bonne pratique de la consultation personnelle et de la relecture en anatomie et cytologie pathologiques en cancérologie (rapport intégral)

CONTEXT

The "Standards, Options and Recommendations" (SOR) project, which started in 1993, is a collaboration between the French Federation of Cancer Centres (FNCLCC), the 20 French Regional Cancer Centres, and specialists from French public universities, general hospitals and private clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and the outcome of cancer patients.

OBJECTIVE

To develop good practice guidelines for second opinion in anatomic and surgical pathology in oncology, in collaboration with the French Society for Anatomic and Surgical Pathology.

METHOD

The methodology is based on a literature review and critical appraisal by a multidisciplinary group of experts who define the CPGs using the definitions of the Standards, Options and Recommendations project. Once the guideline has been defined, the document is submitted to independent reviewers for review.

RESULTS

The working group defined four types of second opinions in anatomic and surgical pathology: personal consultation, inter-institutional consultation, peer review consultation for a scientific survey, intra-departmental consultation in the context of quality control. The main recommendation is that second opinion should respect the patients' rights and the medical ethics code. For each of the four situations defined recommendations have been developed, taking this principle into consideration.

Mitochondrial DNA haplotyping revealed the presence of mixed up benign and neoplastic tissue sections from two individuals on the same prostatic biopsy slide

DNA typing was requested to investigate a presumptive cancer diagnosis error by confirming whether benign and cancerous prostatic tissue in the same presurgical haematoxylin and eosin stained slide belonged to the same person. After independent histological re-examination of the slide by a pathologist, manual slide dissection was used to guarantee independent and high recovery DNA isolation from each tissue section, avoiding carryover and background contamination. Nuclear DNA quantification performed by real time polymerase chain reaction (PCR) revealed the absence of human DNA for short tandem repeat (STR) typing. Mitochondrial DNA was only obtained by performing PCR of very short fragments ( approximately 100 bp), indicating high DNA degradation. Different low frequency hypervariable region I haplotypes were obtained from each tissue section (normal tissue section haplotype: 16224C, 16234T, 16311C, 16356C; cancer tissue section haplotype: 16256T, 16270T, 16293G). Only the normal tissue section haplotype matched that obtained from the patient's blood sample, indicating that the cancer tissue section originated from an unknown patient. These results supported the hypothesis of sample mix up during block processing or slide preparation by a carryover mechanism. Mitochondrial genetic typing is recommended to exclude the possibility of carryover artefacts when low DNA content and high degradation compromise conventional STR typing.

Improving patient safety by examining pathology errors

A considerable void exists in the information available regarding anatomic pathology diagnostic errors and their impact on clinical outcomes. To fill this void and improve patient safety, four institutional pathology departments (University of Pittsburgh, Western Pennsylvania Hospital, University of Iowa Hospitals and Clinics, and Henry Ford Hospital System) have proposed the development of a voluntary, Web-based, multi-institutional database for the collection and analysis of diagnostic errors. These institutions intend to use these data proactively to implement internal changes in pathology practice and to measure the effect of such changes on errors and clinical outcomes. They believe that the successful implementation of this project will result in the study of other types of diagnostic pathology error and the expansion to national participation. The project will involve the collection of multi-institutional anatomic pathology diagnostic errors in a large database that will facilitate a more detailed analysis of these errors, including their effect on patient outcomes. Participating institutions will perform root cause analysis for diagnostic errors and plan and execute appropriate process changes aimed at error reduction. The success of these interventions will be tracked through analysis of postintervention error data collected in the database. Based on their preliminary studies, these institutions proposed the following specific aims: Specific aim #1: To use a Web-based database to collect diagnostic errors detected by cytologic histologic correlation and by second-pathologist review of conference cases. Specific aim #2: To analyze the collected error data quantitatively and generate quality performance reports that are useful for institutional quality improvement programs. Specific aim #3: To plan and implement interventions to reduce errors and improve clinical outcomes, based on information derived from root cause analysis of diagnostic errors. Specific aim #4: To assess the success of implemented interventions by quantitative measure of postinterventional errors and clinical outcomes and by qualitative assessment by project participants. Funding for this project was approved by the Agency for Health Care Research and Quality in September 2002, and data collection and analysis are ongoing. Over 5000 errors have been collected in the database, and the clinical outcomes of these errors have been tracked. At a national meeting in November 2003, root cause analysis was performed to determine causes of errors. The findings of these root cause analyses have been presented at national pathology meetings and are currently being published.

A microdissection and molecular genotyping assay to confirm the identity of tissue floaters in paraffin-embedded tissue blocks

CONTEXT

A recurring problem in surgical pathology practice is specimen mix-up and floater contamination. While many cases can be resolved histologically, a significant number remain unclear and may have serious clinical and medicolegal implications.

OBJECTIVES

To design a microdissection and genotyping assay to identify contaminating floater tissues in paraffin-embedded tissues that is optimized for small samples, and to use the assay to resolve a series of clinical cases with floater tissues.

MATERIALS AND METHODS

Twenty-one cases of possible tissue floater contamination in paraffin-embedded tissue blocks were included. Using 4 unstained, 4-microm-thick histologic sections, multiple sites were microdissected under direct visualization either by hand or by laser capture microdissection. Nonneoplastic and neoplastic tissues were sampled. Polymerase chain reaction was performed for a panel of 10 polymorphic microsatellite markers at 1p34, 3p26, 5q21, 9p21, 10q23, and 17p13. Allele size and content were analyzed semiquantitatively by fluorescent capillary electrophoresis, and the genotypes for the tissues in the paraffin-embedded tissue blocks were compared for identity.

RESULTS

Tissue identification was successful in all cases, despite small tissue sample size and fixation effects. Comparative analysis of neoplastic tissue floaters and the presumptive source tumor was performed when possible to control for possible allelic loss or microsatellite instability.

CONCLUSIONS

Microdissection and genotyping are effective and reliable means to objectively resolve problems of possible floater contamination. Even minute tissue samples provide sufficient DNA template for polymerase chain reaction microsatellite analysis. Because of the potential clinical implications of floaters, we recommend that all suspected floaters that would change a diagnosis from benign to malignant be subjected to genotyping assay to confirm the identity of the floater tissue.

Observer accuracy in estimating proportions in images: implications for the semiquantitative assessment of staining reactions and a proposal for a new system

BACKGROUND

The results of immunohistochemical staining are often assessed by semiquantitative scoring. However, these scoring systems are usually non-standardised and there has been little evaluation of the accuracy and reliability of this subjective assessment.

AIMS

To assess the accuracy of observer estimation of proportions of objects in an image.

METHODS

Images were generated that contained known proportions of pink squares in grids of 50 x 50 and 100 x 100 squares. Observers were shown each image for five seconds in random order and either estimated the proportion of pink squares or selected the image (from a pair of images) that contained the greater proportion of pink squares. The observers were four consultant histopathologists, seven trainee histopathologists, and six control non-histopathologists.

RESULTS

The raw estimations of proportions showed a close correlation with the real proportions, with correlation coefficients of 0.94 and 0.95 for consultant and trainee histopathologists on the 50 x 50 grids. However, the performance in the comparison task was much higher, with an almost perfect classification for grids of equal size even when the proportions only differed by 5%.

CONCLUSIONS

Histopathologists can estimate proportions of objects in an image with a reasonable degree of accuracy in this abstract test system. All observers, whether histopathologists or not, can discriminate between proportions that are only 5% different in equal sized image grids. This suggests that the generation and use of carefully calibrated reference images could greatly improve the accuracy and reliability of semiquantitative scoring of immunohistochemical or any other staining.

Audit and internal quality control in immunohistochemistry

AIMS

Although positive and negative controls are performed and checked in surgical pathology cases undergoing immunohistochemistry, internal quality control procedures for immunohistochemistry are not well described. This study, comprising a retrospective audit, aims to describe a method of internal quality control for immunohistochemistry. A scoring system that allows comparison between cases is described.

METHODS

Two positive tissue controls for each month over a three year period (1996-1998) of the 10 antibodies used most frequently were evaluated. All test cases undergoing immunohistochemistry in the months of April in this three year period were also studied. When the test case was completely negative for a given antibody, the corresponding positive tissue control from that day was examined. A marking system was devised whereby each immunohistochemical slide was assessed out of a possible score of 8 to take account of staining intensity, uniformity, specificity, background, and counterstaining. Using this scoring system, cases were classified as showing optimal (7-8), borderline (5-6), or unacceptable (0-4) staining.

RESULTS

Most positive tissue controls showed either optimal or borderline staining with the exception of neurone specific enolase (NSE), where most slides were unacceptable or borderline as a result of a combination of low intensity, poor specificity, and excessive background staining. All test cases showed either optimal or borderline staining with the exception of a single case stained for NSE, which was unacceptable.

CONCLUSIONS

This retrospective audit shows that immunohistochemically stained slides can be assessed using this scoring system. With most antibodies, acceptable staining was achieved in most cases. However, there were problems with staining for NSE, which needs to be reviewed. Laboratories should use a system such as this to evaluate which antibodies regularly result in poor staining so that they can be excluded from panels. Routine evaluation of immunohistochemical staining should become part of everyday internal quality control procedures.

Identity testing in cervical carcinoma in case of suspected mix-up

The histopathologic diagnosis is the cornerstone of modern oncology. But mix-ups of specimens can occur at any stage. The resection of a 1.2 cm polypoid cervical mass in a 25-year-old woman showed a poorly differentiated adenocarcinoma prospectively staged as T1b1 (International Federation of Gynecology and Obstetrics IB1). Even after complete embedding and serial sectioning of the whole cervix of the hysterectomy specimen after radical hysterectomy, only adenocarcinoma in situ, but no invasive tumor, was seen. To exclude a mix-up of the specimens, identity testing of the paraffin-embedded material was performed by microsatellite analysis. For both materials, we established identical results after testing the microsatellite loci HumTH01, HumVWA, HumFGA, HumACTBP2, HumF13B, and HumD8S1132. The resulting probability of identity came to 99.9999%, excluding a mix-up of the specimens. Archival paraffin-embedded specimens can be used to establish identity and can prevent the wrong patient from having major surgery.

What levels of agreement can be expected between histopathologists assigning cases to discrete nominal categories? A study of the diagnosis of hyperplastic and adenomatous colorectal polyps

AIMS

To assess the levels of agreement between histopathologists for a two-class nominal categorization process--the discrimination between hyperplastic and adenomatous colorectal polyps.

METHODS

Fifty hyperplastic and 50 adenomatous polyps received consecutively in the laboratory were categorized by nine histopathologists, and the level of agreement between all observers and the original diagnosis was assessed using kappa statistics.

RESULTS

For the eight observers with 11 months or more experience in histopathology, there was a high level of agreement with kappa statistics ranging from 0.84 to 0.98. This process was performed rapidly with an average of 13 to 22 seconds spent on each case. One observer with only 6-weeks' experience of histopathology had a lower overall level of agreement with kappa statistics ranging from 0.46 to 0.54, but the performance on the later cases was much higher.

CONCLUSIONS

The level of agreement in the distinction between hyperplastic and adenomatous colorectal polyps is high among histopathologists with at least moderate amounts of experience in histopathology. The one virtually naïve observer showed a marked learning response during the study without feedback on case outcome. This suggests that histopathologists are very reliable in assigning cases to distinct nominal categories and that learning of these processes occurs early in a histopathologist's career.

Prevalence of inter-institutional anatomic pathology slide review: a survey of current practice

Multiple studies have demonstrated discrepancy rates between original and review histopathologic diagnoses of up to 30% with a mean of approximately 10%. In view of these rates of discrepancy, several authorities, including the Association of Directors of Anatomic and Surgical Pathology, have recommended in-house review of all outside materials before commencement of therapy. We used a mail survey to determine the degree of compliance with these recommendations among pathology groups in the United States. Mail surveys were sent to six randomly selected hospitals from each state (300 total). The survey included demographic questions, including surgical pathology caseload, size of hospital (beds), and type of hospital (community-general, non-academic-tertiary care, or academic-tertiary care). The survey asked whether the hospital required review of all outside slides before the performance of surgery. If not, was such a policy encouraged but not required. The survey also asked whether in-house review of outside cases had disclosed any significant differences in pathologic diagnoses. Finally, the survey questioned whether any discrepancies between an internal and external surgical pathology diagnosis had been discovered following radical surgery. One hundred twenty-six usable responses were obtained. Fifty-five of these were from hospitals self-described as community-general, seven were from hospitals describing themselves as non-academic-tertiary care, and the remaining 61 hospitals described themselves as academic-tertiary care institutions. Sixty-three institutions stated they had a requirement for in-house review of outside material, with 46 of 61 academic-tertiary centers having such a requirement. Thirty-seven of 55 community-general hospitals did not require in-house review of outside material before surgery could be performed. One hundred ten of the 126 institutions returning surveys either encouraged or required review of outside material. Ninety-five institutions reported that they had at least one outside case in which their diagnosis was significantly discordant with that rendered by the referring pathologist. Sixty (48%) of the 126 institutions reported at least one case in which a discrepancy was found between the outside biopsy diagnosis and the internal diagnosis rendered on material obtained by radical surgery. Approximately half of all responding institutions have a requirement for in-house review of outside material prior to surgery. A majority of institutions requiring such review have found discrepancies between the in-house diagnoses and those rendered by referring laboratories.