False-positive Papanicolaou (PAP) test rates in the College of American Pathologists PAP education and PAP proficiency test programs: evaluation of false-positive responses of high-grade squamous intraepithelial lesion or cancer to a negative reference diagnosis

An audit of 1632 routinely collected cervical cancer screening smears from 398 women in Germany: Results from the TeQaZ Study

OBJECTIVE

There is evidence in Germany that half of the cervical cancer (CC) cases had undergone screening frequently in the decade preceding their diagnosis, signaling cytology quality issues. This study investigates routine smear assessment accuracy in Germany.

METHODS

Within a population-based case-control study in 9 German states, we recruited cases (women with a histologically confirmed diagnosis of CC) and population controls (women with no history of CC or hysterectomy). Two independent expert cytologists audited Pap smears taken within the 10 years preceding CC diagnosis (cases)/study entry (controls). We report the prevalence of positive results, as well as routine assessment's accuracy, as sensitivity, specificity, false-positive and false-negative rates along with 95% confidence intervals (95% CI). We also examined cases' smear history, to investigate possible false-positive recurrence.

RESULTS

We audited 1632 smears of 392 women (18.9% cases, 81.1% controls). In the routine assessment, the overall prevalence of positive results was 4.5% (29.0% among cases). According to the expert audit, the overall prevalence of positive results was 7.7% (40.8% among cases). When restricting analyses to the 3 years preceding diagnosis/study entry, this prevalence increased to 11.9% overall (61.4% among cases). The overall sensitivity of the routine assessment was 54.9% (66.8% for cases).

CONCLUSION

As cytology remains an important part of CC screening, quality issues must be urgently addressed in Germany. Shifting to objective methods such as primary high-risk HPV screening followed by triaging may help CC elimination in Germany.

Challenging lesions in cervical cytology: The elusive HSIL

Cervical cytology has been an integral part of cervical cancer screening since the mid-20th century with the implementation of screening protocols utilising Pap testing. During that time, cervical cancer has gone from the leading cause of cancer deaths in women to not even appearing in the top 10 causes of US cancer deaths. However, despite its long and widespread use, cervical cytology remains a diagnostically challenging area in the practice of cytopathology. Of particular importance for diagnosticians is the accurate diagnosis of high-grade squamous intraepithelial lesions (HSILs), given the significant risk of progression to invasive cervical cancer and the importance to patient management. Therefore, this review is presented in order to highlight the diagnostic features of HSIL, its various appearances, and important benign and neoplastic differential considerations with an emphasis on morphological clues that can aid in distinguishing between these different processes.

Interpretation pitfalls and malignant mimics in cervical cytology

Cervical cytology has remained a diagnostically challenging area despite its long and widespread use. At least part of this challenge has stemmed from the cytomorphologic overlap between benign and neoplastic processes. The present review has highlighted select benign processes that present diagnostic pitfalls. For each of these, we have discussed the pertinent cytologic features and emphasized the morphologic clues that will aid in distinguishing the benign entities from the neoplastic processes they mimic.

Pattern of cervical biopsy results in cases with cervical cytology interpreted as higher than low grade in the background with atrophic cellular changes

Objective:

The cytomorphological changes associated with atrophic cellular pattern (ACP) in cervical cytology smears may mimic high-grade squamous intraepithelial lesion (HSIL). Due to this, there may be higher chances of cytomorphological overinterpretation in cases with ACP. Estrogen therapy (ET) (topical or systemic) would reverse the changes related to atrophy and repeat Pap smear after ET should correct the false positives. This approach would minimize the unindicated invasive interventions. However, performing immediate biopsies following “higher than low-grade squamous intraepithelial lesion (LSIL) (atypical squamous cells-cannot exclude HSIL, low-grade squamous intraepithelial lesions-cannot exclude HSIL, and HSIL) interpretations” in such cases, is a general trend. Pap smears with “higher than LSIL interpretations” in association with ACP over a period of 10 years were selected.

Materials and Methods:

A total of 657,871 cases over 10 years were reviewed, of which 188 Pap smears interpreted as higher than LSIL interpretations with ACP were selected randomly for this study.

Result:

Of these 188 cases, 67 underwent biopsies which were reviewed and compared with 67 biopsies performed for “higher than LSIL interpretation” cases without ACP. The follow-up biopsy material was reviewed including elective p16 immunohistochemistry with other clinical details including high-risk HPV test results as indicated.

Conclusion:

The findings demonstrated that Pap smears with ACP have higher false positives due to tendency for cytomorphologic overinterpretation as compared to non-ACP group.

HPV Infection Significantly Accelerates Glycogen Metabolism in Cervical Cells with Large Nuclei: Raman Microscopic Study with Subcellular Resolution

Using Raman microscopy, we investigated epithelial cervical cells collected from 96 women with squamous cell carcinoma (SCC) or belonging to groups I, IIa, IIID-1 and IIID-2 according to Munich III classification (IIID-1 and IIID-2 corresponding to Bethesda LSIL and HSIL groups, respectively). All women were tested for human papillomavirus (HPV) infection using PCR. Subcellular resolution of Raman microscopy enabled to understand phenotypic differences in a heterogeneous population of cervical cells in the following groups: I/HPV⁻, IIa/HPV⁻, IIa/HPV⁻, LSIL/HPV⁻, LSIL/HPV⁺, HSIL/HPV⁻, HSIL/HPV⁺ and cancer cells (SCC/HPV⁺). We showed for the first time that the glycogen content in the cytoplasm decreased with the nucleus size of cervical cells in all studied groups apart from the cancer group. For the subpopulation of large-nucleus cells HPV infection resulted in considerable glycogen depletion compared to HPV negative cells in IIa, LSIL (for both statistical significance, ca. 45%) and HSIL (trend, 37%) groups. We hypothesize that accelerated glycogenolysis in large-nucleus cells may be associated with the increased protein metabolism for HPV positive cells. Our work underlines unique capabilities of Raman microscopy in single cell studies and demonstrate potential of Raman-based methods in HPV diagnostics.

The Differential Diagnosis of Reparative Changes and Malignancy: Performance in the College of American Pathologists Pap Education and Proficiency Testing Programs

Context.—

Repair is a challenging diagnosis and a significant source of false-positive (FP) interpretations in cervical cytology. No large-scale study of performance of repair in the liquid-based era has been performed.

Objective.—

To evaluate the performance of repair in the College of American Pathologists Pap Education and Proficiency Testing (PT) programs.

Design.—

The FP rate for slides classified as repair was evaluated by preparation type, participant type (cytotechnologist, pathologist, or laboratory), and program. The specific misdiagnosis category and individual slide performance were also evaluated. The rate of misclassification of slides as repair by participants for other diagnostic categories in the Pap Education program was assessed.

Results.—

The overall FP rate was 1700 of 12 715 (13.4%). There was no significant difference by program or preparation type. Within the Education program there was no difference by participant type, but pathologists' FP rate in the PT program (47 of 514, 9.1%) was significantly better than cytotechnologists in the PT program (51 of 380, 13.4%) and pathologists in the Education program (690 of 4900, 14.1%). High-grade squamous intraepithelial lesions/cancers (HSIL+) accounted for 1380 of 1602 FP interpretations (86%) in Education, but 43 of 98 (43.9%) in PT. Most slides had a low rate of misclassification, but a small number were poor performers. False-negative diagnosis of HSIL+ as repair was less common, ranging from 0.7% to 1.8%.

Conclusions.—

Despite initial indications that liquid-based cytology might reduce the rate of misclassification of repair, FP interpretations remain common and are no different by preparation type. Misclassification is most commonly as HSIL or carcinoma, potentially resulting in significant patient harm.

Systemic cervical cytology training and quality control programs can improve the interpretation of Papanicolaou tests

INTRODUCTION

There is no national cervical screening program or national standards for cervical cytology quality control in China. Since 2013, systematic training and quality control programs were implemented in the Papanicolaou testing process at Jinan KingMed Diagnostics. Pathologists were required to complete 1 year of cytology study in the KingMed Diagnostics Cytology School, including 6 months of a diagnostic course and 6 months of practical training in the clinical laboratory. In this study, we compared the Papanicolaou abnormal reporting rates before and after the implementation systematic training and quality control programs.

MATERIALS AND METHODS

Systematic cytology training and quality control (QC) programs were implemented in 2013. Results from 997,162 cases of liquid-based cytology (LBC) and 100,066 cases of conventional Papanicolaou smears (CPS) rendered between 2008 and 2015 at Jinan KingMed Diagnostics were collected and analyzed.

RESULTS

After implementation of training and programs, the abnormal reporting rates of atypical squamous cells of unknown significance (ASC-US), low-grade squamous intraepithelial lesions (LSIL), atypical squamous cells cannot exclude HSIL (ASC-H), atypical glandular cells (AGC), and high-grade squamous intraepithelial lesions (HSIL) in LBC were significantly increased. Similar trends were also observed in CPS reporting, except for ASC-H, squamous cell carcinoma, and AGC, probably due to the small percentages of these categories.

CONCLUSIONS

The study demonstrates the importance of the formal cytology training and QC programs to ensure standardized and effective cervical cancer screening in undeveloped countries, which account for the largest percentage of the world's annual incidence of cervical cancer and with a largely unscreened population.

Endocervicoscopy and Biopsy to Detect Cervical Intraepithelial Squamous Neoplasia in Nonvisible Squamocolumnar Junction With Unsatisfactory Colposcopy: A Pilot Study

The aim of this study was to investigate the practical utility of endocervicoscopy and targeted biopsy in high-risk human papilloma virus-positive women with abnormal squamous cells on cervical cytology and unsatisfactory colposcopy with nonvisible squamocolumnar junction. Seventy-seven high-risk human papilloma virus-positive patients with abnormal cervical cytology for squamous cells bearing type 3 transformation zone were enrolled. Endoscopic examination of the endocervical epithelium, with office-based continuous-flow hysteroscopy after application of acetic acid 5%, followed by targeted biopsies and consequent large loop excision of the transformation zone was carried out. Sensitivity, specificity, positive predictive value and negative predictive value of endocervicoscopy, and orientated biopsy were confronted with the results of large loop excision of the transformation zone (referral test). The sensitivity and specificity of endocervicoscopy and orientated biopsy for low-grade cervical intraepithelial neoplasia were 53% and 81%, respectively, while the sensitivity and specificity for high-grade cervical intraepithelial neoplasia were 64% and 47%, respectively. The positive predictive value for low-grade cervical intraepithelial neoplasia was 64% and for high-grade cervical intraepithelial neoplasia was 88%. The negative predictive value for low-grade cervical intraepithelial neoplasia was 87% and for high-grade cervical intraepithelial neoplasia was 41%. Endocervicoscopy is a safe, office-based technique. It is a reliable method to detect the transformation zone in patients with type 3 transformation zone and unsatisfactory colposcopy. It potentially allows target biopsy of the transformation zone but presents a relatively low specificity/negative predictive value to predict high-grade cervical intraepithelial neoplasia, thus negative biopsy results should be interpreted with caution.

Study of 2 years follow-up of referral patients with abnormal Pap smear

Background:

Abnormal Pap smear consists of premalignant or malignant cervical lesions. Many of premalignant cervical lesions will never progress to invasive malignancy, or even may regress over the time. Thus, there is always a risk of overtreatment of patients with an abnormal Pap smear. A long-term follow-up of these patients can reveal final events associated with each subtype of abnormal Pap smear, and, therefore, help us to prevent unnecessary interventions. The aim of our study was to present 2 years follow-up of referral patients with abnormal Pap smear.

Materials and Methods:

A total of 334 consecutive women aged more than 16 who were referred with an abnormal Pap smear were entered into the study. Patients were followed with biannual Pap smear and annual colposcopy and biopsy for 2 years.

Results:

At baseline, the majority of patients with abnormal Pap smear were normal on colposcopy and biopsy (68% and 86%, respectively). Six months after first abnormal Pap smear majority of patients in each group showed a significant regress to normal or less invasive lesion (P < 0.001). Twelve patients (4%) had no change in Pap smear, whereas 313 (94%) had at least one stage improvement. Only nine (3%) patients had deteriorated Pap smear after 6 months. All 308 patients who underwent colposcopy and biopsy had normal Pap smear 24 months after the first abnormal Pap smear.

Conclusion:

Pap smear is associated with a high rate of false-positive results. In addition, the majority of low-grade cervical lesions can spontaneously regress. A long-term follow-up of a patient with abnormal Pap smear can help us to avoid needless interventions.

Recommendations on Quality Control and Quality Assurance in Cervical Cytology

OBJECTIVE

We aimed to critically evaluate the importance of quality control (QC) and quality assurance (QA) strategies in the routine work of uterine cervix cytology.

STUDY DESIGN

We revised all the main principles of QC and QA that are already being implemented worldwide and then discussed the positive aspects and limitations of these as well as proposing alternatives when pertinent.

RESULTS

A literature review was introduced after highlighting the main historical revisions, and then a critical evaluation of the principal innovations in screening programmes was conducted, with recommendations being postulated.

CONCLUSIONS

Based on the analysed data, QC and QA are two essential arms that support the quality of a screening programme.

Mock gynecologic cytology proficiency testing as a milestone assessment tool for anatomic pathology residents

INTRODUCTION

One of the major aims of the Next Accreditation System is to move toward an outcomes-based evaluation system where each accredited medical residency program must demonstrate that its residents are competent in performing the essential tasks necessary for clinical practice. Because all pathologists who sign-out or screen Papanicolaou (Pap) tests are required to pass an annual 10-slide gynecologic cytology proficiency test (PT), we developed mock PT modules as a tool for assessing competency.

MATERIALS AND METHODS

In 2007, we introduced mock proficiency testing with 3 distinct modules, each consisting of 3 10-slide test sets (10 ThinPrep, 10 SurePath, and 10 conventional Pap slides). Each module was administered at 3 different time points. We evaluated the following parameters: (1) performance differences between Pap preparations; (2) performance over time; (3) performance before and after initiation of one-on-one teaching sessions with cytotechnologists in 2009; and (4) quality of test slides.

RESULTS

Residents showed improvement over time, and overall scores did not differ significantly among ThinPrep, SurePath, and conventional slide sets. The average score for the first test set was significantly higher for residents who received formal training by a cytotechnologist than for those who did not. Overall, 16 of 90 slides were misclassified by 40% or more of residents, half of which exhibited glandular abnormalities.

CONCLUSIONS

The objective assessment provided by mock PT is a useful tool for both faculty and residents.