Cytologic-histologic correlation: Where are we now, and where are we going?

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.

A Combined Cyto- and Histopathological Diagnostic Approach Reduces Time to Diagnosis and Time to Therapy in First Manifestation of Metastatic Spinal Disease: A Cohort Study

Malignant spinal lesions (MSLs) are frequently the first manifestation of malignant disease. Spinal care, diagnostic evaluation, and the initiation of systemic therapy are crucial for outcomes in patients (pts) with advanced cancer. However, histopathology (HP) may be time consuming. The additional evaluation of spinal lesions using cytopathology (CP) has the potential to reduce the time to diagnosis (TTD) and time to therapy (TTT). CP and HP specimens from spinal lesions were evaluated in parallel in 61 pts (CP/HP group). Furthermore, 139 pts in whom only HP was performed were analyzed (HP group). We analyzed the TTD of CP and HP within the CP/HP group. Furthermore, we compared the TTD and TTT between the groups. The mean TTD in CP was 1.7 ± 1.7 days (d) and 8.4 ± 3.6 d in HP (p < 0.001). In 13 pts in the CP/HP group (24.1%), specific therapy was initiated based on the CP findings in combination with imaging and biomarker results before completion of HP. The mean TTT in the CP/HP group was 21.0 ± 15.8 d and was significantly shorter compared to the HP group (28.6 ± 23.3 d) (p = 0.034). Concurrent CP for MSLs significantly reduces the TTD and TTT. As a result, incorporating concurrent CP for analyzing spinal lesions suspected of malignancy might have the potential to enhance pts' quality of life and prognosis in advanced cancer. Therefore, we recommend implementing CP as a standard procedure for the evaluation of MSLs.

E-learning module for cytopathology education based on virtual microscopy

INTRODUCTION

In cytopathology education, Virtual Microscopy e-learning modules (VM-eLM) have achieved remarkable results in the improvement and personalization of learning. However, it remains to be determined whether these modules can significantly contribute to improving the accuracy of cytological diagnosis. The aim of this work was to create a VM-eLM for gynecologic cytopathology education designed to improve screening and interpretation skills in two groups of cytologists: experienced and nonexperienced.

MATERIALS AND METHODS

The module was designed in Moodle with both Whole Slide Images and Static Images taken from Papanicolaou smears that were diagnosed as: negative for intraepithelial lesion, low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, squamous cell carcinoma, or adenocarcinoma. We assessed the effectiveness of the module using 1) clinical quality indicators to measure skill development and 2) a user survey.

RESULTS

After training, participants significantly improved their cytological screening skills, decreasing their false negative diagnosis by 78% in the non-experienced group and eliminating them entirely in the experienced group. Nonexperienced participants also significantly increased their recognition of low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion by 31% and 50%, respectively. Participants positively evaluated the module, highlighting its novelty, the possibility to train remotely, the immediate feedback and the quality of the Whole Slide Images.

CONCLUSIONS

We designed, implemented and tested a VM-eLM for Gynecologic Cytopathology Education that improved cytological screening skills for both non-experienced and experienced cytologists, also increasing the diagnostic accuracy of preinvasive lesions by less experienced cytologists. The module was positively evaluated by participants, who perceived an improvement in their interpretive skills.

Liquid-Based Cervical Cytology: Monitoring the Laboratory Quality Indicators

Aim

Many developments in cervical cancer screening have happened in the past century, helping women in earlier detection of cervical cancer and its precursors. Cytology still holds the fort as being a specific test, though it suffers in sensitivity. As a part of the quality control program, the aim of the study is to determine the total number of abnormal liquid-based cervical cytology (LBC) at our center and correlate the abnormal LBC with histology and human papillomavirus (HPV) DNA test results.

Method

Retrospective analysis of 4286 LBC screening cases was carried out over a period of 5 years. For cytology-histology correlation, cervical biopsy and cytology test results were analyzed. The two-tier grading system for biopsy interpretation was used. HPV DNA test results wherever available were correlated.

Results

Of the 4286 LBC cases, 157 samples (3.7%) were unsatisfactory for evaluation, 3915 samples (91.3%) were negative for intra-epithelial lesion or malignancy, and 214 samples (5%) showed epithelial cell abnormality. ASC-US was reported in 60 cases (1.4%), ASC-H in 35 cases (0.8%), LSIL in 47 cases (1.1%), HSIL in 41 cases (1.0%), squamous cell carcinoma in a single case (0.02%), and atypical glandular cells in 30 cases (0.7%). The ASC/SIL ratio was 1.07:1. The CHC major discrepancy was calculated as 16.2%. The concordance of HSIL on cytology and biopsy as a measure of PPV is 94.4%. Of the epithelial cell abnormalities, 24 cases were positive for high-risk HPV (hrHPV). Molecular test results of 2737 samples showed HPV detected in 50 cases, of which 24 cases were positive for hrHPV.

Conclusion

The study helped us to analyze the quality parameters of our cytopathology laboratory which are within the acceptable limits.

Use of nongynecologic cytologic-histologic correlation to identify patterns of error: An institutional experience

BACKGROUND

Quality management practices empower cytology laboratories to deliver consistent, high-quality patient care. Monitoring of key performance indicators is one way by which laboratories can identify patterns of error and focus their improvement activities. Cytologic-histologic correlation (CHC) identifies error by retrospectively reviewing cytology cases when discordant surgical pathology diagnoses are reported. Analysis of CHC data can elucidate patterns of error and direct quality improvement initiatives.

METHODS

CHC data of nongynecologic cytology specimens were reviewed over a 3-year period (2018-2021). Errors were separated by anatomic site and classified as either sampling or interpretive errors.

RESULTS

A total of 364 discordant cases were identified out of 4422 cytologic-histologic pairs (a discordant rate of 8%). The majority (272; 75%) were sampling errors, with fewer interpretive errors (92; 25%). Sampling errors were found to occur most commonly in lower urinary tract and lung. Interpretive errors were most commonly found in lower urinary tract and thyroid.

CONCLUSIONS

Nongynecologic CHC data can be a valuable resource for cytology laboratories. By studying the types of errors, quality improvement activities can be targeted toward problem areas.

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.

A Deep Learning System to Predict the Histopathological Results From Urine Cytopathological Images

Background

Although deep learning systems (DLSs) have been developed to diagnose urine cytology, more evidence is required to prove if such systems can predict histopathology results as well.

Methods

We retrospectively retrieved urine cytology slides and matched histological results. High-power field panel images were annotated by a certified urological pathologist. A deep learning system was designed with a ResNet101 Faster R-CNN (faster region-based convolutional neural network). It was firstly built to spot cancer cells. Then, it was directly used to predict the likelihood of the presence of tissue malignancy.

Results

We retrieved 441 positive cases and 395 negative cases. The development involved 387 positive cases, accounting for 2,668 labeled cells, to train the DLS to spot cancer cells. The DLS was then used to predict corresponding histopathology results. In an internal test set of 85 cases, the area under the curve (AUC) was 0.90 (95%CI 0.84-0.96), and the kappa score was 0.68 (95%CI 0.52-0.84), indicating substantial agreement. The F1 score was 0.56, sensitivity was 71% (95%CI 52%-85%), and specificity was 94% (95%CI 84%-98%). In an extra test set of 333 cases, the DLS achieved 0.25 false-positive cells per image. The AUC was 0.93 (95%CI 0.90-0.95), and the kappa score was 0.58 (95%CI 0.46-0.70) indicating moderate agreement. The F1 score was 0.66, sensitivity was 67% (95%CI 54%-78%), and specificity was 92% (95%CI 88%-95%).

Conclusions

The deep learning system could predict if there was malignancy using cytocentrifuged urine cytology images. The process was explainable since the prediction of malignancy was directly based on the abnormal cells selected by the model and can be verified by examining those candidate abnormal cells in each image. Thus, this DLS was not just a tool for pathologists in cytology diagnosis. It simultaneously provided novel histopathologic insights for urologists.

Recognition of cervical precancerous lesions based on probability distribution feature guidance

INTRODUCTION:

Cervical cancer is a high incidence of cancer in women and cervical precancerous screening plays an important role in reducing the mortality rate.

METHOD:

- In this study, we proposed a multichannel feature extraction method based on the probability distribution features of the acetowhite (AW) region to identify cervical precancerous lesions, with the overarching goal to improve the accuracy of cervical precancerous screening. A k-means clustering algorithm was first used to extract the cervical region images from the original colposcopy images. We then used a deep learning model called DeepLab V3+ to segment the AW region of the cervical image after the acetic acid experiment, from which the probability distribution map of the AW region after segmentation was obtained. This probability distribution map was fed into a neural network classification model for multichannel feature extraction, which resulted in the final classification performance.

RESULT:

Results of the experimental evaluation showed that the proposed method achieved an average accuracy of 87.7%, an average sensitivity of 89.3%, and an average specificity of 85.6%. Compared with the methods that did not add segmented probability features, the proposed method increased the average accuracy rate, sensitivity, and specificity by 8.3%, 8%, and 8.4%, respectively.

CONCLUSION:

Overall, the proposed method holds great promise for enhancing the screening of cervical precancerous lesions in the clinic by providing the physician with more reliable screening results that might reduce their workload.

Cervical Cytology–Histology Correlation Based on the American Society of Cytopathology Guideline (2017) at the Russian National Medical Research Center for Obstetrics, Gynecology, and Perinatology

Recent evidence suggests that a cytology–histology correlation (CHC) with discrepancy detection can both evaluate errors and improve the sensitivity and specificity of the cytologic method. We aimed to analyze the errors in cytologic–histologic discrepancies according to the CHC protocol guideline of the American Society of Cytopathology (2017). This retrospective study included 273 patients seen at the National Medical Research Center of Obstetrics, Gynecology and Perinatology (Moscow, Russia) between January 2019 and September 2021. The patients’ mean age was 34 ± 8.1 years. The cytology–histology agreement was noted in 158 cases (57.9%). Major discrepancies were found in 21 cases (7.6%), while minor discrepancies were noted in 93 cases (34.1%). The reason for 13 (4.8%) discrepancies was a colposcopy sampling error and, in 46 (16.8%) cases, the reason was a Papanicolaou (PAP) test sampling error. The discrepancy between primary and reviewed cytology was due interpretive errors in 13 (4.8%) cases and screening errors in 42 (15.4%) cases. We demonstrated that the ASC guidelines facilitate cervical CHC. A uniform application of these guidelines would standardize cervical CHCs internationally, provide a scope for the inter-laboratory comparison of data, and enhance self-learning and peer learning.

Quality metrics in cervical cytopathology: A single institutional study

OBJECTIVES

Implementation of quality control measures ensures acceptable performance by a laboratory. This study aims to assess the quality of cervical cytopathology reporting using quality metrics like atypical squamous cells (which include both atypical squamous cells of undetermined significance and atypical squamous cell -cannot rule out high grade squamous intraepithelial lesion)/squamous intraepithelial lesion (ASC/SIL), cytohistological correlation (CHC) and positive predictive value (PPV) of Papanicolaou (Pap) smears for squamous lesions of cervix.

METHODS

A retrospective study of Pap smears from 2015 to 2020 was performed. The quality metrics analysed include diagnoses of ASCUS, ASC-H and ASCUS/SIL ratio, CHC and PPV. Cases with cervical biopsies/hysterectomy were included for CHC, and discrepancy was defined as discordance in diagnostic category between cytology and histology in the CHC.

RESULTS

A total of 22,695 cervical cytology smears were reported. Unsatisfactory smears (n = 290) were excluded. Squamous lesions were reported in 233 smears, and the Bethesda system of nomenclature was followed. A definitive diagnosis (SILs and SCC) was given in 74% of cases. ASCUS and ASC-H were reported in 47 and 14 cases, respectively. The most common lesion on Pap smear was high-grade squamous intraepithelial lesion (HSIL; n = 92), followed by low-grade squamous intraepithelial lesion (LSIL; n = 64), and two were ungradable SIL. Squamous cell carcinoma (SCC) was reported in 14 smears. The ASC/SIL ratio was 0.38. CHC (n = 139) was 100% for ASC-H, LSIL, SCC and 84.7% for HSIL. A review of discrepant cases suggested sampling and interpretational discrepancy in five and one cases, respectively. The PPV of Pap smear for squamous lesions was 96.4%.

CONCLUSION

It is essential to have good quality cytopathology reports for early identification, which enables appropriate management. The most commonly used quality indicator for cytopathology is the ASCUS/SIL ratio. This study suggests the inclusion of the CHC and PPV values as quality metrics for Pap smear, since these are easily measurable and serve as a good indicator of quality in cervical cytopathology reporting.

Use of micronucleus assays for the prediction and detection of cervical cancer: a meta-analysis

Cervical cancer (CC) is the fourth most common cancer in women; the survival rates depend strongly on its early detection. The Pap test is the most frequently used diagnostic tool, but due to its limited sensitivity/specificity, additional screening tests are needed. Therefore, we evaluated the use of micronucleus (MN) assays with cervical cells for the prediction and diagnosis of CC. MN reflects structural and numerical chromosomal aberrations. A search was performed in Pubmed, Scopus, Thomson ISI and Google Scholar. Subsequently, meta-analyses were performed for different grades of abnormal findings in smears and biopsies from patients which were diagnosed with CC. Results of 21 studies in which findings of MN experiments were compared with data from Pap tests show that higher MN frequencies were found in women with abnormal cells that are indicative for increased cancer risks. MN frequency ratios increased in the order inflammation (2.1) < ASC-US and ASC-H (3.3) < LGSIL (4.4) < HGSIL (8.4). Furthermore, results are available from 17 investigations in which MN were scored in smears from patients with neoplasia. MN rates increased with the degree of neoplasia [CIN 1 (4.6) < CIN 2 (6.5) and CIN 3 (10.8)] and were significantly higher (8.8) in CC patients. Our meta-analysis indicates that the MN assay, which is easy to perform in combination with Pap tests, may be useful for the detection/prediction of CC. However, standardization (including definition of the optimal cell numbers and stains) and further validation is necessary before the MN test can be implemented in routine screening.

Diagnosis of cervical precancerous lesions based on multimodal feature changes

To realize the automatic diagnosis of cervical intraepithelial neoplasia (CIN) cases by preacetic acid test and postacetic acid test colposcopy images, this paper proposes a method of cervical precancerous lesion diagnosis based on multimodal feature changes. First, the preacetic acid test and postacetic acid test colposcopy images were registered based on cross-correlation and projection transformation, and then the cervical region was extracted by the k-means clustering algorithm. Finally, a deep learning network was used to extract features and classify the preacetic acid test and postacetic acid test cervical images after registration. Finally, the proposed method achieves a classification accuracy of 86.3%, a sensitivity of 84.1%, and a specificity of 89.8% in 60 test cases. Experimental results show that this method can make better use of the multimodal features of colposcopy images and has lower requirements for medical staff in the process of data acquisition. It has certain clinical significance in cervical cancer precancerous lesion screening systems.

Moving forward-the 2019 ASCCP Risk-Based Management Consensus Guidelines for Abnormal Cervical Cancer Screening Tests and Cancer Precursors and beyond: implications and suggestions for laboratories

The 2019 ASCCP Risk Based Management Consensus Guidelines for prevention of cervical cancer promote clinical management recommendations aligned with our increased understanding of HPV biology and cervical carcinogenesis. They employ HPV-based testing as the basis for risk estimation, allow for personalized risk-based management by incorporating knowledge of current results with prior results, and streamline incorporation of new test methods as they are validated. They continue to support the principles of "equal management for equal risk" and "balancing harms and benefits" adopted in the 2012 version of the guidelines. These updated guidelines will be able to adjust for decreasing CIN3+ risks as more patients who received HPV vaccination reach screening age. Pathology organizations were closely involved in the development of these guidelines. Herein the pathologists who served as representatives to the 2019 ASCCP guidelines steering committee and workgroups, summarize the changes that are relevant to laboratories, pathologists, and cytotechnologists. Prior relevant screening and reporting recommendations that have not been widely and/or inconsistently adopted by laboratories are also discussed and considerations for modification of laboratory practices offered.