Cytohistologic Discrepancies

Cytologic-Histologic Correlation Practices for Nongynecologic Cytology Specimens: A Survey by the College of American Pathologists Cytopathology Committee

CONTEXT.—

Cytologic-histologic correlation (CHC) is a Clinical Laboratory Improvement Amendments-mandated requirement for gynecologic cytology, but no similar requirement exists for nongynecologic cytology. This study presents the findings from a College of American Pathologists survey of nongynecologic cytology practice patterns.

OBJECTIVE.—

To survey the current CHC practices for nongynecologic cytology.

DESIGN.—

Data were analyzed from a survey developed by the committee and distributed to participants in the Nongynecologic Cytopathology Education Program mailing.

RESULTS.—

Adoption of CHC for nongynecologic cytology cases is worldwide, with 88.5% of institutions performing CHC on these specimens, a substantial increase from previous years. Performance of CHC varied by institution type, with clinic or regional/local independent laboratories and national/corporate laboratories performing CHC significantly less frequently than hospitals, university hospitals/academic medical centers, and Veterans Administration/Department of Defense hospital institutions. Most CHC was performed concurrently in real time, when the corresponding surgical specimen was reviewed. Selection for real-time concurrent CHC was by the interpreting pathologist, the pathologist diagnosing the surgical biopsy sample or cytopathology case, or both. Sampling was by far the most common reason for discordance. A 2-step difference was the most frequent threshold for discordance between cytology and surgical specimens, but this criterion varied among institutions, with no majority definition. The positive predictive value of a positive cytology finding was calculated rarely in North American institutions but was calculated more frequently in international institutions.

CONCLUSIONS.—

CHC practices for nongynecologic cytopathology mirror those found for CHC of gynecologic cytopathology.

Cytology-histology correlation of cervical Papanicolaou smears and biopsies performed at a single institution compared to those performed at different institutions

OBJECTIVE

Cytology-histology correlation (CHC) is the gold standard of quality assurance in cytology laboratories to ensure appropriate patient treatment, and as an educational tool for cytology laboratory personnel. If cervical Pap smears (CPs) and cervical biopsies (CBs) are performed at different institutions, these benefits may be lost.

METHODS

All CBs performed at our institution from 1 January 2019 to 31 December 2019 with adequate CPs performed in the 6 months prior to the CB were included in this retrospective review. We compared the CHC for CPs and CBs performed at a single institution to the CHC for CPs and CBs performed at different institutions, with a focus on the proportion of overcalls on CPs, as those are the most challenging discrepant CHC to manage clinically. We used the American Society of Cytology guidelines for our discrepancy assessment grid. A Chi-squared test was used to compare the proportions of the populations. The P-value was set at < 0.05.

RESULTS

Of the 305 CBs in our study population, 69 had a CP performed at our institution and 236 had a CP performed at an outside institution. The CHC for CBs and CPs performed at a single institution showed statistically significantly less disagreement than the CHC for those performed at different institutions (P < 0.05). Further, CBs and CPs performed at a single institution had statistically significantly fewer overcalls than CBs and CPs performed at different institutions (P < 0.05).

CONCLUSION

This study further supports the use of CHC, and in light of our findings we recommend that a patient's CPs and CBs are performed at the same institution. If performing a CP and CB at the same institution is not feasible, a prospective consultation review of the CP by the institution performing the CB should be strongly considered. Further study, including an evaluation of the reason for the discrepancy in discordant cases may better elucidate the reasons for better CHC agreement when CP and CB are performed at the same institution.

Analytical and post analytical phase of an ISO 15189:2012 Certified cytopathology laboratory-a five year institutional experience

Objective:

Analytical and post analytical phase are integral part of total quality management system and include steps from submission of slides till reports are dispatched. The present study was conducted to analyze the analytical and post analytical phase of the ISO15189:2012 certified cytopathology laboratory. It was also intended to study the various errors which were encountered and steps taken to reduce these discrepancies.

Methods:

The study included all documents of quality program from 1 November 2014 till 31 Oct 2019 in medical institute situated in north Himalayan region of India. All the data was recorded and analyzed for analytical and post analytical phase.

Results:

The number of samples received in cytopathology lab was 21,566 with total quality errors of 5.19%. Out of these pre-analytical errors were 55%, analytical 10.5% and post analytical errors constituted 34.4%. The maximum errors detected were due to typographical errors followed by delayed turnaround time. Cyto-histopathological discordance was 10.5% in non-gynecological cases and 2.2% in gynecological cases.

Conclusion:

Analytical and post analytical phase analysis is essential to minimize the errors and improve the quality of cytopathology lab. Cyto-histopathological correlation is valuable for continuous data tracking in the cytopathology with analytical errors analysis. Maintenance of external, internal quality program, turnaround time with documentation, continuous training and communication with clinician is fundamental for quality improvement in any cytopathology lab. Acknowledgement of nonconformance with root cause analysis and sincere efforts to minimize them is the basic key for successful quality management.

Trends in Thyroid Fine-Needle Aspiration Cytology Practices: Results From a College of American Pathologists 2016 Practice Survey

CONTEXT.—

The College of American Pathologists periodically surveys laboratories to determine changes in cytopathology practices. We report the results of a 2016 survey concerning thyroid fine-needle aspiration (FNA).

OBJECTIVE.—

To provide a cross-sectional survey of thyroid cytology practices in 2016.

DESIGN.—

In 2016, a survey was sent to 2013 laboratories participating in the College of American Pathologists Non-Gynecologic Cytology Education Program (NGC-A) requesting data from 2015-2016 on several topics relating to thyroid FNA.

RESULTS.—

A total of 878 laboratories (43.6% of 2013) replied to the survey. Radiologists performed the most thyroid FNA procedures in most laboratories (70%; 529 of 756), followed by endocrinologists (18.7%; 141 of 756), and most of these were performed under ultrasound guidance (92.1%; 699 of 759). A total of 32.6% of respondents (251 of 769) provided feedback on unsatisfactory rates for nonpathology providers who performed FNA. Intraprocedural adequacy assessment was primarily performed by attending pathologists (77.4%; 490 of 633) or cytotechnologists (28.4%; 180 of 633). Most laboratories used the Bethesda System for Reporting Thyroid Cytopathology (89.8%; 701 of 781) and performed molecular testing based on clinician request (68.1%; 184 of 270) rather than FNA diagnosis. Correlation of thyroid excisions with prior cytology results most often occurred retrospectively (38.4%; 283 of 737) and was used for pathologist interpretive quality assurance purposes.

CONCLUSIONS.—

These survey results offer a snapshot of national thyroid FNA cytology practices in 2016 and indicate that standardized cytology terminology is commonly used; pathologists perform most immediate adequacy assessments for thyroid FNA; laboratories use correlation statistics to evaluate pathologists' performance; and molecular tests are increasingly requested for indeterminate interpretations, but reflex molecular testing is rare.

Estimate of false-positive breast cancer diagnoses from accuracy studies: a systematic review

Background

False-positive histological diagnoses have the same consequences of overdiagnosis in terms of unnecessary treatment. The aim of this systematic review is to assess their frequency at needle core biopsy (CB) and/or surgical excision of the breast.

Methods

PubMed, Embase, Cochrane Library were systematically searched up to 30 October 2015. Eligibility criteria: cross-sectional studies assessing diagnostic accuracy of CB compared with surgical excision; studies assessing reproducibility of pathologists reading the same slides. Outcomes: false-positive rates; Misclassification of Benign as Malignant (MBM) histological diagnosis; K statistic. Independent reviewers extracted data and assessed quality using an adapted QUADAS-2 tool.

Results

Sixteen studies assessed CB false-positive rates. In 10 studies (41 989 screen-detected lesions), the range of false-positive rates was 0%–7.1%. Twenty-seven studies assessed pathologists' reproducibility. Studies with consecutive, random or stratified samples of all the specimens: at CB the MBM range was 0.25%–2.4% (K values 0.83–0.98); at surgical excision, it was 0.67%–1.2% (K values 0.86–0.94). Studies with enriched samples: the MBM range was 1.4%–6.2% (K values 0.57–0.86). Studies of cases selected for second opinion: the MBM range was 0.29%–12.2% (K values 0.48 and 0.50).

Conclusions

High heterogeneity of the included studies precluded formal pooling estimates. When considering studies of higher sample size or methodological quality, false-positive rates and MBM are around 1%. The impact of false-positive histological diagnoses of breast cancer on unnecessary treatment, as well as that of overdiagnosis, is not negligible and is of importance in clinical practice.

Interpretive Diagnostic Error Reduction in Surgical Pathology and Cytology: Guideline From the College of American Pathologists Pathology and Laboratory Quality Center and the Association of Directors of Anatomic and Surgical Pathology

CONTEXT

Additional reviews of diagnostic surgical and cytology cases have been shown to detect diagnostic discrepancies.

OBJECTIVE

To develop, through a systematic review of the literature, recommendations for the review of pathology cases to detect or prevent interpretive diagnostic errors.

DESIGN

The College of American Pathologists Pathology and Laboratory Quality Center in association with the Association of Directors of Anatomic and Surgical Pathology convened an expert panel to develop an evidence-based guideline to help define the role of case reviews in surgical pathology and cytology. A literature search was conducted to gather data on the review of cases in surgical pathology and cytology.

RESULTS

The panel drafted 5 recommendations, with strong agreement from open comment period participants ranging from 87% to 93%. The recommendations are: (1) anatomic pathologists should develop procedures for the review of selected pathology cases to detect disagreements and potential interpretive errors; (2) anatomic pathologists should perform case reviews in a timely manner to avoid having a negative impact on patient care; (3) anatomic pathologists should have documented case review procedures that are relevant to their practice setting; (4) anatomic pathologists should continuously monitor and document the results of case reviews; and (5) if pathology case reviews show poor agreement within a defined case type, anatomic pathologists should take steps to improve agreement.

CONCLUSIONS

Evidence exists that case reviews detect errors; therefore, the expert panel recommends that anatomic pathologists develop procedures for the review of pathology cases to detect disagreements and potential interpretive errors, in order to improve the quality of patient care.

Diagnostic ability and factors affecting accuracy of endoscopic ultrasound-guided fine needle aspiration for pancreatic solid lesions: Japanese large single center experience

BACKGROUND

Several studies have investigated the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for pancreatic lesions, but they have included only limited patient populations. This study aimed to clarify the diagnostic accuracy of EUS-FNA in a large number of pancreatic lesions, and to describe the factors that influence it.

METHODS

From March 1997 to May 2010, 944 consecutive patients who had undergone EUS-FNA for pancreatic solid lesions were evaluated retrospectively. Factors affecting EUS-FNA accuracy were then analyzed.

RESULTS

A total of 996 solid pancreatic lesions were sampled by EUS-FNA. The overall sampling adequacy and diagnostic accuracy of these lesions were 99.3 % (989/996) and 91.8 % (918/996), respectively. The sensitivity and specificity for differentiating malignant from benign lesions were 91.5 % (793/867) and 97.7 % (126/129), respectively. The diagnostic performance was significantly higher when both cytological and cell-block examinations were carried out than with only cytological examination. In multivariate analysis, final diagnosis, location of lesion, lesion size, availability of on-site cytopathological evaluation, and experience of EUS-FNA procedure were independent factors affecting the accuracy of EUS-FNA. On-site cytopathological evaluation and lesion size were found to be the most weighted factors affecting diagnostic accuracy.

CONCLUSIONS

EUS-FNA for pancreatic solid lesions yielded a high accuracy and low complication rate. Both cytological and cell-block preparations and on-site cytopathological evaluation contributed to improve the accuracy. The diagnostic ability of EUS-FNA was less for smaller lesions, and repeated procedures may be needed if malignancy is suspected.

Expression of neuronal markers in the endometrium of women with and those without endometriosis

STUDY QUESTION

How do the expression patterns of neuronal markers differ in the endometrium of women with and without endometriosis?

SUMMARY ANSWER

The neuronal markers, PGP9.5, NGFp75 and VR1, are expressed in the endometrium at levels that do not differ between women with and without endometriosis.

WHAT IS KNOWN ALREADY

Aberrant neuronal growth within the uterus may contribute to abnormal fertility and uterine dysfunction. However, controversy still exists as to whether aberrant innervation in the endometrium is associated with gynaecological pathology such as endometriosis. This may reflect the use of subjective methods such as histology to assess the innervation of the endometrium. We, therefore, employed a quantitative method, western blotting, to study markers of endometrial innervation in the presence and absence of endometriosis.

STUDY DESIGN, SIZE, DURATION

This study included 45 women undergoing laparoscopic examination for the diagnosis of endometriosis. Endometrial samples were analysed by western blot for the expression of neuronal and neurotrophic markers, PGP9.5, VR1 and NGFp75.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Endometrial pipelle biopsies were obtained from patients with (n = 20, study group) and without (n = 25, control group) endometriosis. Tissue was analysed by immunohistochemistry and western blot analysis for the expression of pan-neuronal marker, PGP9.5, sensory nociceptive marker, TPVR1, and low-affinity neurotrophic growth factor receptor, NGFRp75.

MAIN RESULTS AND THE ROLE OF CHANCE

PGP9.5, NGFp75 and VR1 were expressed in the endometrium of women, independent of the presence of endometriosis. Furthermore, the expression level of PGP9.5, VR1 and NGFp75 did not alter between the two cohorts of women.

LIMITATIONS, REASONS FOR CAUTION

Studies of this nature are subject to the heterogeneous nature of patient population and tissue samples despite attempts to standardize these parameters. Hence, further studies using similar methodology will be required to confirm our results.

WIDER IMPLICATIONS OF THE FINDINGS

Our results highlight that sensory neuronal markers are present in women with and without endometriosis. Future work will assess what the targets of the endometrial nerves are and investigate their function, their impact on endometrial biology and, in particular, whether aberrant neuronal function, rather than the mere presence of neuronal function, could be the root cause of subfertility and/or pain affecting many endometriosis sufferers. Our results do not, however, confirm the previous paradigm of increased innervation in the endometrium of women with endometriosis, nor the use of nerve cell detection from pipelle biopsies to diagnose endometriosis.

Quality control in cervicovaginal cytology by cytohistological correlation

OBJECTIVE

Frequent studies attest to the correlation of cytological interpretations with defined histopathological entities. Nevertheless, as part of quality control, cytology laboratories are required to compare Papanicolaou smear reports with those of cervical biopsies to search for discrepancies. We have attempted to determine and categorize the causes of existing discrepancies in our laboratory in order to clarify the source of errors.

METHODS

We reviewed 670 cervical smears that were paired with subsequent punch biopsy or endocervical curettage samples, obtained within 2 months of the cytology, and found out that 60 smear-biopsy pairs were discrepant regarding the diagnosis. These cases were categorized into four error groups after careful re-evaluation of the original smear and biopsy slides.

RESULTS

In 51 (85%) of 60 cervical smear-biopsy pairs with reports that disagreed, the initial diagnoses of both cervical smear and biopsy were confirmed by the review opinion; in these cases, cytology and biopsy 'sampling errors' were responsible for 40 and 11 instances of discrepancy, respectively. Seven cases (11.1%) were discrepant due to 'smear interpretation errors' and consisted of five cases with initial under-diagnosis and two cases with initial over-diagnosis. One case (1.7%) was due to 'screener error'. In another case, discordance was due to cervical 'biopsy interpretation error', with initial over-diagnosis as squamous intraepithelial lesion.

CONCLUSION

In this retrospective study, we determined the causes of cytohistological discrepancies in cervical samples. The main explanation for discrepancy was 'sampling error'.

False-positive EUS-guided FNA cytology for solid pancreatic lesions

BACKGROUND

The currently accepted paradigm is that the false-positive (FP) rate for EUS-guided fine-needle aspiration (EUS-FNA) cytologic analysis of a pancreatic lesion is less than 1%.

OBJECTIVE

To assess the FP rate of EUS-FNA in patients who underwent surgical resection for presumed pancreatic cancer.

DESIGN

Retrospective study.

SETTING

Tertiary-care referral center.

PATIENTS

This study involved 367 patients with solid pancreatic lesions in whom EUS-FNA cytology results were interpreted as positive or suspicious for malignancy, which resulted in subsequent surgical resection.

INTERVENTION

Surgical resection.

MAIN OUTCOME MEASUREMENTS

The FP diagnosis was defined as EUS-FNA cytology specimens being reported as "positive" or "suspicious for malignancy" but that were later proven to be benign on surgical pathology.

RESULTS

The FP rate for EUS-FNA was 4 of 367 (1.1%) when only "positive" cytology findings were interpreted as malignant and 14 of 367 (3.8%) when both suspicious and positive cytology findings were interpreted as malignant. Among the 4 cases falsely interpreted as positive, 1 was falsely diagnosed cytologically as a neuroendocrine tumor and 3 as adenocarcinomas. All FP specimens showed chronic pancreatitis on surgical pathology. The incidence of discordance between cytology and surgical pathology did not change over time (2000-2006: 8/188 [4.3%] vs 2007-2010: 6/179 [3.4%]; P = .79).

LIMITATIONS

Retrospective study at a single center.

CONCLUSION

In a retrospective cohort trial, the FP rate for EUS-FNA of solid pancreatic lesions was 1.1%. Findings of the current study are in line with previous studies that have evaluated the FP cytology rates with EUS-FNA of solid lesions. FP cases transpired primarily as a result of cytologic misinterpretation in the setting of chronic pancreatitis.

Diagnostic Concordance of Histologic Lung Cancer Type Between Bronchial Biopsy and Cytology Specimens Taken During the Same Bronchoscopic Procedure

Context.—The diagnosis of lung cancer is often confirmed by cytology and biopsy specimens obtained during a bronchoscopic procedure. At our institution, these specimens are read by different pathologists, and the rate of concordance was not known.

Objectives.—To evaluate the concordance rate in the diagnosis of lung cancer types between cytology and biopsy specimens and to correlate discordance with patient outcome.

Design.—Specimens obtained during the same procedure, between January 1, 2000, and December 31, 2005, were identified. Cases with cytology and biopsy specimens positive for cancer were evaluated for concordance of histologic type, small cell versus non–small cell lung carcinoma. Cases with different types were considered discordant, and slides were reviewed.

Results.—Of 231 cases, 225 (97.4%) had concordant diagnoses. Discordance was the result of misinterpretation of undifferentiated carcinoma, overinterpretation of squamous dysplasia, interpretation of suboptimal specimens with necrosis and crush artifact, and sampling error.

Conclusions.—Even though the cytology and biopsy specimens were reviewed by different pathologists, the concordance rate for histologic type at our institution was high, emphasizing that this is a safe practice. The few discordant cases did not affect the patient's outcome.

Limiting the Use of Atypical/Inconclusive as a Category in Nongynecologic Cytology Specimens

Context.—Atypical has served as a descriptive term in cytology since the birth of the specialty by Dr Papanicolaou. This indeterminate diagnosis often results in repeat biopsies or additional tissue sampling and a needless delay in patient care if used inappropriately. Because of the definitional ambiguity of this term and the associated physician frustration, we have made a concerted effort at Methodist Hospital since 1995 to minimize the use of atypical as a diagnostic category.

Objective.—To evaluate whether the dissolution of the atypical category has increased our cytologic-histologic discordance rate to more than the published reference range.

Design.—From March 3, 2006, through December 31, 2008, all nongynecologic cases with atypical/indeterminate listed as the general diagnostic category were identified and retrieved from our laboratory data files. We then assessed the cytologic-histologic correlation rate during the corresponding time frame.

Results.—A total of 48 atypical cases (0.2%) from 19 347 nongynecologic specimens were identified. Of the atypical cases, 52% (25 of 48) had intradepartmental consultation, 58% (28 of 48) had additional preparations examined, and 29% (14 of 48) documented limitations because of poor preservation. Our cytologic-histologic discrepancy rate for the period was 5.5% (214 of 3912 cases), with 89.3% (191 of 214 cases) resulting from sampling issues. On review of the small percentage of cytologic interpretative discrepancies, only one case was unhampered by less than 10% tumor cellularity or poor preservation.

Conclusions.—Not using atypical as a diagnostic category, unless defined by Bethesda guidelines, has not affected our cytologic-histologic correlation rate.

Clinical performance of human papillomavirus E6 and E7 mRNA testing for high-grade lesions of the cervix

Infection with high-risk (HR) human papillomavirus (HPV) is the major cause of cervical cancer. However, relatively few infections progress to malignant disease. Progression to malignancy requires the overexpression of the E6 and E7 genes in the integrated HPV genome. It follows that the E6 and E7 transcripts could be useful markers of disease progression. The study presented here tests this possibility, using data from colposcopy and from cytological and histological tests to compare RNA assays for the E6 and E7 genes with DNA testing. A total of 180 women underwent colposcopy, cytology, and biopsy of suspected lesions (143 cases). Cervical brush specimens were analyzed for HPV DNA and for E6 and E7 mRNA. DNA from HR HPV was found in 57.8% of the specimens; E6 and E7 transcripts were found in 45%. The rates of detection of HPV DNA and of E6 and E7 transcripts were 33.3% and 25%, respectively, for specimens with normal findings; 51.4% and 31.9%, respectively, for specimens with cervical intraepithelial neoplasia grade 1 (CIN1); and 61.1% and 44.2% for specimens with CIN2, respectively. All specimens with CIN3 and 95.5% of specimens from patients with squamous cell carcinoma were positive by both assays. Thirty-seven patients with normal colposcopy findings did not undergo biopsy. HPV DNA and mRNA transcripts were found in 32.4% and 18.9% of these cases, respectively. Comparisons with cytological tests produced similar results. Overall, the mRNA tests showed a higher specificity than the DNA tests for high-grade lesions (72.7% and 56.2%, respectively) and a higher positive predictive value (59.3% and 49.0%, respectively). These findings suggest that mRNA assays could be more powerful than DNA testing for predicting the risk of progression and offer a strong potential as a tool for triage and patient follow-up.

RNA (E6 and E7) assays versus DNA (E6 and E7) assays for risk evaluation for women infected with human papillomavirus

In the majority of cases, high-risk human papillomavirus (HR HPV) infections regress spontaneously, with only a small percentage progressing to high-grade lesions. Current screening methods are based on DNA detection. An alternative would be to monitor expression of the E6 and E7 viral oncogenes continuously expressed by malignant phenotypes. In the work reported in this paper, we compared the two methods for a group of women with high-risk HPV infections. Cervical specimens from 400 women, previously found to be HPV DNA positive, were analyzed for HPV DNA by a liquid hybridization assay and typed by multiplex PCR (for types 16, 18, 31, and 33). Identification of HR HPV E6 and E7 RNA transcripts was performed using real-time reverse transcription-PCR and nucleic acid sequence-based amplification assays. Results were compared with concurrent cytological data. HR HPVs were found in 61.2% of patients. The most common genotype was HPV type 16 (HPV-16) (47.1%), followed by HPV-18, HPV-31, and HPV-33. Nine percent of cases involved other genotypes. Among 223 HPV DNA-positive samples, only 118 were positive in the RNA test. Among HPV DNA-positive patients with normal cytology, we detected E6 and E7 RNA transcripts in two cases (18.2%). The rate of detection increased gradually with the grade of the observed lesions, rising from 20% for patients with atypical squamous cells of undetermined significance to 48.1% for women with low-grade squamous intraepithelial lesions and 86.3% for those with high-grade squamous intraepithelial lesions. These results suggest that testing for HPV E6 and E7 transcripts could be a useful tool for screening and patient management, providing more accurate predictions of risk than those obtained by DNA testing.

Laboratory medicine quality indicators: a review of the literature

We summarize information on quality indicators related to laboratory testing from published literature and Internet sources to assess current gaps with respect to stages of the laboratory testing process, the Institute of Medicine (IOM) health care domains, and quality measure evaluation criteria. Our search strategy used various general and specific terms for clinical conditions and laboratory procedures. References related to a potential quality indicator associated with laboratory testing and an IOM health care domain were included. With the exception of disease- and condition-related indicators originating from clinical guidelines, the laboratory medicine quality indicators reviewed did not satisfy minimum standard evaluation criteria for quality or performance measures (ie, importance, scientific acceptability, and feasibility) and demonstrated a need across the total laboratory testing process for consistently specified, useful, and evidence-based, laboratory-related quality and performance measures that are important to health outcomes and meaningful to health care stakeholders for which laboratories can be held accountable.

The effect of continuous monitoring of cytologic-histologic correlation data on cervical cancer screening performance

CONTEXT

The use of Papanicolaou (Pap) test cytologic-histologic correlation in quality improvement activities is not well studied.

OBJECTIVE

To determine if continuous monitoring of correlation data improves performance.

DESIGN

Participants in the College of American Pathologists Q-Tracks program (213 laboratories) self-reported the number of Pap test-histologic biopsy correlation discrepancies every quarter for up to 8 years. A mixed linear model determined if the length of participation in the Q-Tracks program was associated with improved performance. Main outcome measures were predictive value of a positive Pap test, Pap test sensitivity, sampling sensitivity, and proportion of positive histologic diagnoses following a Pap test diagnosis of atypical squamous cells or atypical glandular cells.

RESULTS

Institutions evaluated 287,570 paired Pap test-histologic correlation specimens and found 98,424 (34.2%) true-positive Pap test correlations, 19,006 (6.6%) false-positive Pap test correlations, and 6575 (2.3%) false-negative Pap test correlations. The mean predictive value of a positive Pap test, sensitivity, screening and interpretive sensitivity, sampling sensitivity, and proportion of positive histologic diagnoses following a Pap test diagnosis of atypical squamous or glandular cells were 83.6%, 93.7%, 99.2%, 94.2%, 60.3%, and 38.8%, respectively. Longer participation was significantly associated with a higher predictive value of a positive Pap test (P = .01), higher Pap test sensitivity (P = .002), higher Pap test sampling sensitivity (P = .03), and higher proportion of positive histologic diagnoses for a Pap test diagnosis of atypical squamous cells (P < .001).

CONCLUSIONS

Long-term monitoring of cytologic-histologic correlation is associated with improvement in cytologic-histologic correlation performance.

Higher diagnostic accuracy with the ThinPrep method in a simulated intraoperative environment

OBJECTIVE

To compare the accuracy of intraoperative fine needle aspiration cytology samples prepared by the ThinPrep method to conventional cytological methods. Specimen adequacy and turn around time (TAT) were also assessed.

METHODS

Fifty consecutive fresh tumours submitted for histological analysis were aspirated and each prepared as follows: (i) direct smear with H&E stain, (ii) direct smear with Pap stain, (iii) ThinPrep slide with H&E stain, and (iv) ThinPrep slide with Pap stain. The slides were randomly distributed to three cytopathologists for interpretation. The quality of the preparation, the diagnosis and the time needed for interpretation were recorded.

RESULTS

Accuracy was measured as the percentage of absolute agreement between the cytological and the histopathological diagnoses of the lesions. Histologically, there were 43 malignant and six benign lesions and one atypical lipoma. The TAT began when the slides/cytolyte specimens arrived at the lab and ended with the pathologist's diagnosis.

CONCLUSIONS

In terms of accuracy and specimen adequacy, ThinPrep slides with Pap stain is the best procedure. This advantage however is offset by the longer testing time.

Use of a new method in reaching consensus on the cause of cytologic-histologic correlation discrepancy

Pathologists exhibit very poor agreement in adjudicating the cause of cytologic-histologic correlation discrepancies, which contributes to problems in designing interventions to reduce discrepancy frequency. In this observational study, we developed a visual method of adjudicating discrepancy cause, termed the No-Blame Box method, which consisted of initially assessing specimen interpretability by separately evaluating specimen quality and the presence of tumor. Five pathologists blindly adjudicated the cause of discrepancy in pulmonary specimens from 40 patients. The kappa statistic of all pathologist pairs in adjudicating discrepancy cause using the No-Blame Box method ranged from 0.400 to 0.796, indicating acceptable to excellent agreement. Pathologists ranged in their assessment of specimen interpretability from 13% to 20%, and in no case did all 5 pathologists concur that a specimen was interpretable. Most discrepancies resulted from pathologists diagnosing noninterpretable samples. Pathologists who used the No-Blame Box showed significant agreement in the adjudication of discrepancy cause.

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.

Variability of practice in anatomic pathology and its effect on patient outcomes

Variability in the delivery of medical care negatively affects patient outcomes and contributes to escalating health care costs. Such heterogeneity exists on geographic, provider-related, institutional, and financial levels. Efforts to reduce it have resulted in the development of evidence-based clinical practice guidelines that have been only inconsistently adopted. Testing patterns in anatomic pathology (AP) also manifest considerable inconsistency, further contributing to suboptimal health outcomes and increased costs. Test variability in AP can be identified in its clinician-dependent preanalytic aspect and in the analytic phase as well, including the gross prosection of specimens, their processing, and reporting formats. To address selected facets of these issues, pathologists have developed practice guidelines that generally are based on "expert" opinion, representing the weakest form of evidence. Interpretative variability in AP has been investigated in numerous published studies that have measuring the "kappa statistic." Few of those analyses have addressed the impact of diagnostic disagreement on patient care; in addition, proposed and effective methods to reduce interpretative variability have only rarely been included.

The "Big Dog" effect: variability assessing the causes of error in diagnoses of patients with lung cancer

PURPOSE

The frequency of diagnostic error in patients who have a lung mass and a pathology specimen is as high as 15%. This study examined the role of inter-pathologist agreement in identifying the cause of error in these patients.

METHODS

Pathologists from six institutions reviewed the slides of 40 patients who had a pulmonary specimen false-negative diagnosis. The initial assessment of error cause arose from cytologic-histologic correlation slide review of discrepant diagnostic samples in patients who had both a bronchial brushing cytologic and surgical specimen. The cause of error was attributed either to clinical sampling (diagnostic material obtained in one but not the other sample) or interpretation (pathologist failed to identify the salient diagnostic features). The pairwise kappa (kappa) statistic was used to calculate interobserver agreement between the review and original diagnoses and between the separate review diagnoses.

RESULTS

The pairwise kappa statistic ranged widely from -0.154 to 1.0, and the pairwise kappa statistic of the slides from one institution was undetermined because that institutional pathologist never made the assessment that error was secondary to interpretation. Agreement for observers within the same institution was better than agreement between observers from different institutions.

CONCLUSION

Pathologists exhibit poor agreement in determining the cause of error for pulmonary specimens sent for cancer diagnosis. We developed a psychosocial hypothesis (the "Big Dog" Effect) that partially explains biases in error assessment. This lack of agreement precludes confident targeting of these errors for quality improvement interventions with prospects of success across a variety of institutions.

Improving Patient Safety Through Quality Assurance

Context.—Anatomic pathology laboratories use several quality assurance tools to detect errors and to improve patient safety.

Objective.—To review some of the anatomic pathology laboratory patient safety quality assurance practices.

Design.—Different standards and measures in anatomic pathology quality assurance and patient safety were reviewed.

Main Outcome Measures.—Frequency of anatomic pathology laboratory error, variability in the use of specific quality assurance practices, and use of data for error reduction initiatives.

Results.—Anatomic pathology error frequencies vary according to the detection method used. Based on secondary review, a College of American Pathologists Q-Probes study showed that the mean laboratory error frequency was 6.7%. A College of American Pathologists Q-Tracks study measuring frozen section discrepancy found that laboratories improved the longer they monitored and shared data. There is a lack of standardization across laboratories even for governmentally mandated quality assurance practices, such as cytologic-histologic correlation. The National Institutes of Health funded a consortium of laboratories to benchmark laboratory error frequencies, perform root cause analysis, and design error reduction initiatives, using quality assurance data. Based on the cytologic-histologic correlation process, these laboratories found an aggregate nongynecologic error frequency of 10.8%. Based on gynecologic error data, the laboratory at my institution used Toyota production system processes to lower gynecologic error frequencies and to improve Papanicolaou test metrics.

Conclusion.—Laboratory quality assurance practices have been used to track error rates, and laboratories are starting to use these data for error reduction initiatives.

Clinical impact and frequency of anatomic pathology errors in cancer diagnoses

BACKGROUND

To the authors' knowledge, the frequency and clinical impact of errors in the anatomic pathology diagnosis of cancer have been poorly characterized to date.

METHODS

The authors examined errors in patients who underwent anatomic pathology tests to determine the presence or absence of cancer or precancerous lesions in four hospitals. They analyzed 1 year of retrospective errors detected through a standardized cytologic-histologic correlation process (in which patient same-site cytologic and histologic specimens were compared). Medical record reviews were performed to determine patient outcomes. The authors also measured the institutional frequency, cause (i.e., pathologist interpretation or sampling), and clinical impact of diagnostic cancer errors.

RESULTS

The frequency of errors in cancer diagnosis was found to be dependent on the institution (P < 0.001) and ranged from 1.79-9.42% and from 4.87-11.8% of all correlated gynecologic and nongynecologic cases, respectively. A statistically significant association was found between institution and error cause (P < 0.001); the cause of errors resulting from pathologic misinterpretation ranged from 5.0-50.7% (the remainder were due to clinical sampling). A statistically significant association was found between institution and assignment of the clinical impact of error (P < 0.001); the aggregated data demonstrated that for gynecologic and nongynecologic errors, 45% and 39%, respectively, were associated with harm. The pairwise kappa statistic for interobserver agreement on cause of error ranged from 0.118-0.737.

CONCLUSIONS

Errors in cancer diagnosis are reported to occur in up to 11.8% of all reviewed cytologic-histologic specimen pairs. To the authors' knowledge, little agreement exists regarding whether pathology errors are secondary to misinterpretation or poor clinical sampling of tissues and whether pathology errors result in serious harm.

Improving Papanicolaou test quality and reducing medical errors by using Toyota production system methods

OBJECTIVE

The objective of the study was to determine whether the Toyota production system process improves Papanicolaou test quality and patient safety.

STUDY DESIGN

An 8-month nonconcurrent cohort study that included 464 case and 639 control women who had a Papanicolaou test was performed. Office workflow was redesigned using Toyota production system methods by introducing a 1-by-1 continuous flow process. We measured the frequency of Papanicolaou tests without a transformation zone component, follow-up and Bethesda System diagnostic frequency of atypical squamous cells of undetermined significance, and diagnostic error frequency.

RESULTS

After the intervention, the percentage of Papanicolaou tests lacking a transformation zone component decreased from 9.9% to 4.7% (P = .001). The percentage of Papanicolaou tests with a diagnosis of atypical squamous cells of undetermined significance decreased from 7.8% to 3.9% (P = .007). The frequency of error per correlating cytologic-histologic specimen pair decreased from 9.52% to 7.84%.

CONCLUSIONS

The introduction of the Toyota production system process resulted in improved Papanicolaou test quality.

Discrepancy analysis, communication, and feedback for cytotechnologist quality improvement of nongynecologic cytopathology

The Clinical Laboratory Improvement Amendments of 1988 (CLIA '88) detail the requirements for the cytotechnologist (CT) who evaluates gynecologic cytopathology specimens. However, the role of the CT in nongynecologic cytopathology is not clearly defined. Furthermore, non gynecologic cytopathology cases are diverse and the screening, interpretative, and diagnostic issues may be quite different from the gynecologic cases. At our institution, the CT and pathologist review nongynecologic cytopathology cases. Since CLIA '88 does not require the CT to screen nongynecologic cytopathology cases, there are few guidelines for quality assessment or quality improvement for the CT regarding nongynecologic cytopathology cases. To provide better understanding of the expectations of the CT and the needs of the pathologist, we developed a system comparing the CT's interpretation to the pathologist's interpretation as a means for enhanced communication and feedback. Using our Laboratory Information System (LIS), we generate a daily report that lists all cases with discrepancy in diagnoses between the CT and pathologist. The general supervisor reviews this report for diagnostic discrepancy in each case. To determine the degree of discrepancy, numerical values are assigned to each primary interpretation. Minor discrepancies are defined as differences less than +/-2.0. Major discrepancies are defined as differences greater than or equal to +/-2.0. For the entire laboratory, the overall percentage of concordant cases was consistently above 80% for each of the 6 mo analysis. Regarding the monthly discrepancies, the proportion of minor discrepancies ranged from 11.09% to 15.44% and the proportion of major discrepancies ranged from 1.40% to 3.56%. The frequency distribution of discrepancies by degree approximates a normal (Gaussian) curve and serves as baseline information that may be used for comparison when there are changes in practice or personnel. The CTs attend slide review sessions conducted by the general supervisor for discussion of cases with major discrepancies. The discrepancy data from individual CTs are useful in counseling and recommending areas for improvement. As the CT and pathologist work cooperatively and in tandem, our system allows for a mechanism by which the expectations and needs of pathologist are communicated to the CT more effectively. We believe our process is a fundamental step in improving CT performance in Nongynecologic cytopathology and keeps the CT informed of complexities of nongynecologic cytopathology.

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.

Variability in Cytologic-Histologic Correlation Practices and Implications for Patient Safety

Context.—The Clinical Laboratory Improvement Amendments of 1988 require that laboratories perform cytologic-histologic correlation, although the optimal methods and the value of performing correlation have not been determined.

Objective.—To determine the similarities and differences in how laboratories perform cytologic-histologic correlation.

Design.—One hundred sixty-two American laboratories were sent a letter requesting copies of the materials they used in the cytologic-histologic correlation process. The returned materials were classified into the categories of forms, logs, and tally sheets. A checklist (derived from the College of American Pathologists Laboratory Accreditation Cytopathology Checklist) was developed to classify the “minimum expected” (15) and “additional” data points that laboratories collected when they performed a correlation.

Participants.—American pathology laboratories.

Main Outcome Measures.—Measures were percentage of laboratories that recorded minimum expected and additional data points and the frequency with which specific minimum expected data points were recorded.

Results.—The response frequency was 32.1%, and a total of 84 cytologic-histologic correlation materials were obtained. The only minimum expected variables recorded on forms or logs by more than 50% of laboratories were cytology case number, sign-out cytology diagnosis, surgical pathology case number, and sign-out surgical pathology diagnosis. Nine (17.3%) laboratories did not record data on forms, logs, or tally sheets. The mean number of minimum expected and additional variables recorded on forms was 6.5 and 8.7, respectively.

Conclusions.—Laboratories record data from the cytologic-histologic correlation process in a number of ways, indicating the lack of standardization of the data collection process.

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.

Cytologic-histologic correlation of nongynecologic cytopathology cases: separation of determinate from indeterminate cytologic diagnoses for analysis and monitoring of laboratory performance

Much of the literature on the quality-assurance aspect of cytologic-histologic correlation (CHC) has focused on gynecologic cytology. For nongynecologic cytopathology, the process is complicated by the use of determinate (positive for malignant cells, negative for malignant cells) and indeterminate (atypical, suspicious, or follicular lesion) diagnostic categories. Here, we illustrate our routine methodology for analyzing CHC data on nongynecologic cytopathology cases by separating determinate from indeterminate cases. A focused list of determinate and indeterminate cytopathology cases with surgical pathology correlation is generated each week. The determinate cases are ascertained as true positive (TP), true negative (TN), false positive (FP), or false negative (TN). The discrepant cases (FP and FN) are investigated to determine the cause (sampling, interpretation, or screening). For indeterminate cases, the surgical pathology outcome (benign, malignant) and suitability of the cytopathology category utilized are reviewed. For the focused period of 4 mo, sensitivity was 70% and specificity was 100%. The most common reason for false-negative diagnoses was a sampling problem in the cytologic specimen; there were no false-positive diagnoses. Malignant outcomes for follicular lesion, atypical, and suspicious diagnoses were 29%, 40%, and 76%, respectively. Data derived from regularly performed CHC are useful in reviewing the diagnostic performance of the laboratory.