Quality assurance in cytology. Rescreening of previously negative smears from high grade squamous intraepithelial lesions

Five-year retrospective review in gynecologic cytopathology: is it time to amend?

INTRODUCTION

According to the Clinical Laboratory Improvement Amendments 1988 regulations, 5-year retrospective review (5YRR) of normal Papanicolaou tests in patients with a newly diagnosed high grade squamous intraepithelial lesion or above (HSIL+) is mandatory. Since this mandate has been in place, a multitude of changes have taken place in the screening and management guidelines of cervical cancer. The aim of this study is to assess the role of this mandate in our laboratory and to investigate the lessons learned.

MATERIAL AND METHODS

The cytopathology electronic database and institutional quality assurance records at Loyola University Medical Center were searched from January 2009 to December 2019 to identify all Papanicolaou tests diagnosed as new "HSIL and above" (HSIL+). Major discrepancy (2+) was defined as initial negative diagnosis changed to HSIL+.

RESULTS

A total of 153,083 Papanicolaou tests were performed during this period; out of these, 1452 (0.94%) were diagnosed as HSIL+. A total of 695 HSIL+ Papanicolaou tests had a negative prior Papanicolaou and in 615 of 695 there was agreement with the initial negative diagnosis. In 61 Papanicolaou tests, the initial diagnosis was changed from negative and they were reclassified on review as 3 HSIL, 9 ASC-H, 7 AGC, and 42 ASCUS or LSIL. Major discrepancy rate was calculated as 3 of 695 (0.43%). None required an amended report.

CONCLUSIONS

It is important to revisit the 5YRR as a method of implementing the quality indicators in gynecologic cytology so that the process retains its value without overburdening cytology laboratories and personnel.

Prospective and retrospective review of gynecologic cytopathology: findings from the College of American Pathologists Gynecologic Cytopathology Quality Consensus Conference working group 2

CONTEXT

Two quality metrics for gynecologic cytology are the subject of this review: "prospective rescreening" and "retrospective rescreening."

OBJECTIVE

To offer consensus best practice approaches based on the College of American Pathologists' laboratory-based survey funded by the Centers for Disease Control and Prevention.

DESIGN

The College of American Pathologists submitted a paper-based survey to 1245 laboratories. After review of initial results, follow-up Web-based survey results, and a literature review, consensus best practice statements were presented at a national consensus conference. These statements were discussed and voted upon by conference participants. Results.-A total of 541 laboratories responded to survey questions about prospective and retrospective rescreening. Most laboratories (>85%) prospectively rescreen more than 10% of Pap tests interpreted as negative for intraepithelial lesion or malignancy. Most (72%) report inclusion of less than 20% high-risk cases. Most laboratories use multiple measures to define "high risk." Most laboratories (96.2%) retrospectively rescreen Pap tests from the preceding 5 years only. In most laboratories (71.4%) only Pap test results with high-grade squamous intraepithelial lesion or worse prompt retrospective review.

CONCLUSIONS

The number of Pap tests from high-risk patients should be maximized in prospective and retrospective rescreening. Unsatisfactory Pap tests should also be included. All readily identifiable high-risk human papillomavirus-positive cases with an interpretation of negative for intraepithelial lesion or malignancy should be prospectively rescreened. Cervical biopsy results with high-grade cervical intraepithelial neoplasia or worse (CIN 2+) should trigger retrospective rescreening. Regular feedback should be provided to cytotechnologists and cytopathologists. Upgraded diagnoses from negative for intraepithelial lesion or malignancy to atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion, should be monitored.

Preceding cervical cytology in women with high-grade squamous intraepithelial lesion

OBJECTIVE

To evaluate the preceding cervical cytology and factors leading to cytohistologic discrepancy in women with high-grade squamous intraepithelial lesion (HSIL) histology.

METHODS

The records of women who were found to have histologically confirmed HSIL without any associated invasive and glandular lesions, at Chiang Mai University Hospital between January 2005 and May 2009, were reviewed. Cytohistological discrepancy was defined as HSIL histology preceded by low-grade squamous intraepithelial lesion (LSIL) and atypical squamous cells of undetermined significance (ASC-US) smears.

RESULTS

The records of 436 HSIL cases were reviewed. The mean age of the women was 45.0 ± 9.3 years. The preceding smear abnormalities were as follows: 275 (63.1%) with HSIL; 50 (11.5%) with atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (ASC-H); 40 (9.2%) with squamous cell carcinoma; 35 (8.0%) with LSIL; 32 (7.3%) with ASC-US; and 4 (0.9) with glandular abnormality smears. Overall, the rate of cytohistological discrepancy was 15.4% (95% CI 12.1-19.1%). The small size of HSIL and presence of coexisting LSIL are significant independent predictors for cytohistologic discrepancy.

CONCLUSION

Approximately 15% of HSIL cases are under-diagnosed by cytology. Significant factors leading to cytohistologic discrepancy are lesion size and the presence of coexisting LSIL.

A simple model for potential use with a misclassified binary outcome in epidemiology

STUDY OBJECTIVE

Error in determination of disease outcome occurs in epidemiology, but such error is not usually corrected for in statistical analysis. A method of correction of risk estimates for misclassification of a binary disease outcome is developed here.

METHODS

The method is a simple, closed form correction to the logistic regression estimate. A closed form variance estimate is also developed.

SETTING

The method is illustrated in two studies, a cross sectional survey of cervicitis in Iran in 1996-97, as determined by inflammation on cervical smear specimens, and a case-cohort study of benign proliferative epithelial disease of the breast, in Canada 1980-88.

MAIN RESULTS

The method provides corrected odds ratio estimates and corrects the spurious precision conferred by misclassification.

CONCLUSIONS

The method is easy to apply and potentially useful, although potential failures of the assumptions involved should be borne in mind. It is necessary to give careful consideration to the plausibility or otherwise of the assumptions in the context of the individual study. Correction for misclassification of disease outcome may become more common with the development of readily applicable methods.

Role of Pap Test terminology and age in the detection of carcinoma invasive and carcinoma in situ in medically underserved California women

Our goals were to evaluate Pap Test findings classified by the Bethesda system, and follow up biopsies from participants in the California Breast and Cervical Cancer Control Program (Ca-BCCCP) for: 1) correlation in the detection of carcinoma in situ (CIS) and carcinoma invasive (CI), and 2) age-related trends, with discussion in the context of the 2001 ASCCP Management Guidelines. Women (n = 52,339) who had their initial screening Pap Tests with Ca-BCCCP between January 1995-December 1999 were followed for diagnostic services through December 2000. Descriptive and analytical methods were used in the analysis. Of the Pap results, 81.9% were negative, 10.6% showed infection, 4.7% showed an epithelial abnormality as defined by the Bethesda system (atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesion (LSIL), or high-grade squamous intraepithelial lesion (HSIL)), 0.1% showed squamous-cell cancer (SCC), and 2.7% showed other or unsatisfactory. Subsequent to the initial Pap Test, follow-up results of carcinoma in situ (CIS) and carcinoma invasive (CI) accounted for 0.36% and 0.05% of the population, respectively. Among HSIL Pap Tests (n = 285), 40.7% had follow-up showing CIS. Among SCC Pap Tests, 17.9% had follow-up results of CIS and 28.6% CI. Of the 191 patients with CIS as a follow-up finding, the initial Pap smear showed: HSIL 60.7%, SCC 2.6%, LSIL 10.5%, ASCUS 13.6%, and negative or infection 9.9%. Of the 27 patients with CI, the initial Pap Test showed: HSIL 40.7%, SCC 29.6%, LSIL 7.4%, ASCUS 7.4%, and negative or infection 11.1%. Pap diagnoses of other or unsatisfactory accounted for 2.6% of the Pap results from patients with CIS and 3.7% of Pap results from patients with CI. Except for LSIL, there was an increasing age trend in the number of cases in each of Pap results, with the exception of age 65+ yr. However, the ratio of LSIL and ASCUS to negative cases decreased with age. (P < 0.0001 and 0.0293, respectively). HSIL Pap results indicate a reasonably high probability of CIS and CI. However, approximately 1/3 of patients with CIS and 1/4 of patients with CI presented with Pap diagnoses of less severity than HSIL. When a negative Pap Test result is chosen as reference group, there is a negative age trend for LSIL and ASCUS, and no age trend for other results. These findings all have important implications in the design of follow-up strategies, and support the 2001 ASCCP Consensus Guidelines for the Management of Women with Cervical Abnormalities.

Cervical smear interpretations in women with a histologic diagnosis of severe dysplasia: factors associated with discrepant interpretations

BACKGROUND

Because most low-grade squamous intraepithelial lesions (LSIL) regress spontaneously, the appropriate follow-up of women with a cytologic diagnosis of LSIL has engendered discussion. This retrospective study was undertaken to assess the feasibility of limiting colposcopy to women with cytologic interpretations of high-grade squamous intraepithelial lesions (HSIL) in a high-risk population.

METHODS

The pathology computer files (including files from January to December 1997) of The University Hospital, University of Oklahoma Health Sciences Center, revealed 197 women whose histologic samples were coded as severe dysplasia. Of these, 138 had a cervical smear interpreted in our laboratory before the colposcopic visit. On review, the tissue samples of 119 women met consensus criteria for severe dysplasia.

RESULTS

Original cytologic diagnoses for 119 cytologic smears included 80 (62.7%) that were interpreted as HSIL. After retrospective review, 28 cases with LSIL or less were reclassified as HSIL and were considered to be discrepant for the purpose of this study. Major confounding factors in the original categorization include lack of consistency among the pathologists for the interpretation of metaplastic patterns and specimen adequacy, particularly air-drying artifact. Eleven cases (10.2%) did not have cells identifiable as HSIL because of sampling error and/or severe air-drying artifact.

CONCLUSIONS

These results indicate that a substantial number of histologically verified cases of severe dysplasia can have a smear interpretation of LSIL or less. The factors that hampered recognition of the true severity of the lesion in this series were identified and tabulated.

Is the human papillomavirus test in combination with the Papanicolaou test useful for management of patients with diagnoses of atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesions?

OBJECTIVE

To determine whether human papillomavirus (HPV) testing is useful in the evaluation of patients diagnosed with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL) and whether the HPV test is appropriate as an alternative screening method.

DESIGN

The results of Papanicolaou (Pap) tests and subsequent hybrid capture tube (HCT) II tests for high-risk-type HPV were analyzed for 457 patients. Among these tests, 208 histologic diagnoses were made and correlated with the results of Pap and HPV tests. The sensitivity and specificity of the Pap test, HPV test, and the combined method of Pap and HPV tests to detect cervical intraepithelial neoplasia (CIN) 2/3 and all CIN were also measured.

RESULTS

Sixty (63.8%) of 94 women with LSIL and 31 (26.3%) of 118 women with ASCUS tested positive for high-risk HPV. The sensitivity values for Pap tests in detecting all cases of CIN and CIN 2/3 were 91.4% and 92.9%, respectively. The sensitivity values of HCT II tests using the high-risk probe for detecting all cases of CIN and CIN 2/3 were 62.6% and 88.1%, respectively. Biopsies confirmed that 10 (22.7%) of 44 LSIL patients with high-risk HPV had CIN 2/3, but only 1 (4.5%) of 22 LSIL patients without high-risk HPV had CIN 2/3.

CONCLUSION

Testing for high-risk HPV with the HCT II test is useful in the detection of CIN 2/3 in LSIL groups and in the selection of patients for colposcopy in ASCUS groups, but it is not suitable for cervical cancer screening tests.

Accuracy of Pap tests reported as CIN I

Papanicolaou (Pap) tests reported as CIN I (cervical intraepithelial neoplasia, grade 1) may be subject to laboratory misclassification because of screening and interpretative errors. A peer-groupC consensus review was conducted to measure the misclassification rate of Pap tests reported as CIN I and to analyze the undercalled and overcalled tests for due cause. Four hundred and forty-nine Pap tests originally reported as CIN I were independently reviewed twice by a panel of four pathologists, and disagreements were resolved by consensus review. Results were based on the original screening for the first review and, following the removal of those markings, were based on a second, independent rescreening for the second review. A review result of low-grade squamous intraepithelial lesion (LSIL) and atypical squamous cells of undetermined significance (ASCUS) favoring LSIL was equated with the original CIN I result. Final classification was based on the second consensus review. Misclassified tests were categorized as screening or interpretative errors, based on a comparison of the review classifications. LSIL and ASCUS favoring LSIL were reported in 85.1% and 73.9% of the first and second reviews, respectively. In the final classification there were 362 (80.6%) LSIL and ASCUS-LSIL and 87 (19.4%) misclassifications: 31 (6.9%) undercalls and 56 (12.5%) overcalls. Screening error accounted for 35.5% of undercalled tests, and the remainder were interpretative errors, as were all those overcalled. In this study, Pap tests reported as CIN I were subject to misclassification because of a laboratory error in 19.4% of tests. Reductions in screening and interpretative errors were identified as mechanisms for improving accuracy. Diagn. Cytopathol. 1999;21:129-136.