The role of liquid-based preparation in the evaluation of endometrial cytology

The morphological characteristics and arrangements of cells in the liquid-based cytology preparation of patients with endometrial lesions

BACKGROUND

The accurate cytological diagnosis of endometrial carcinomas by minimally invasive method has a broad application. There are several articles described the morphological characteristics but not arrangements of endometrial lesion cells on LBC slides.

METHODS

A retrospective study was conducted using 175 endometrial samples obtained by direct negative pressure suction with disposable endometrial sampler. All lesions were diagnosed both cytologically and histologically, and the diagnostic results were compared and analyzed.

RESULTS

The cytological diagnoses of polyps, simple or complex hyperplasia, and atypical hyperplasia were highly consistent with the histological diagnosis. The cytological features of polyps and normal endometrium, as well as simple and complex hyperplasia, are the same. Among 82 cases of histologically confirmed adenocarcinoma, the cytological diagnosis were adenocarcinoma cells (46 cases, 56.10%), suspected for adenocarcinoma cells (22 cases, 26.83%), and false negative (14 cases,17.07%). Retrospective reviewing the slide suggest diagnostic parameters such as significantly enlarged nuclei, multistage papillary arrangements, large and numerous nucleoli, and large vacuoles containing neutrophils in the cytoplasm are reliable diagnostic criteria for endometrial carcinoma cells; on the other hand, ignorance of lobulated arrangements and escaped arrangements are the main reasons for missed diagnosis.

CONCLUSIONS

The cytological diagnosis of endometrial lesions not only depends on the morphological characteristics of cells, but also need careful observations of the cellular arrangements.

Advances in diagnostic liquid-based cytology

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

Fractal Dimension, Circularity, and Solidity of Cell Clusters in Liquid-Based Endometrial Cytology Are Potentially Useful for Endometrial Cancer Detection and Prognosis Prediction

Endometrial cancer (EC) in women is increasing globally, necessitating improved diagnostic methods and prognosis prediction. While endometrial histology is the conventional approach, liquid-based endometrial cytology may benefit from novel analytical techniques for cell clusters. A clinical study was conducted at the University of Fukui Hospital from 2012 to 2018, involving 210 patients with endometrial cytology. The liquid-based cytology images were analyzed using cell cluster analysis with Image J software. Logistic regression, ROC analysis, and survival analysis were employed to assess the diagnostic accuracy and prognosis between cell cluster analysis and EC/atypical endometrial hyperplasia (AEH). Circularity and fractal dimension demonstrated significant associations with EC and AEH, regardless of age and cytology results. The ROC analysis revealed improved diagnostic accuracy when combining fractal dimension with cytology, particularly in menopausal age groups. Lower circularity and solidity were independently associated with poor overall survival, while higher fractal dimension values correlated with poorer overall survival in Grades 2 and 3 endometrial cancers. The combination of circularity and fractal dimension with cytology improved diagnostic accuracy for both EC and AEH. Moreover, circularity, solidity, and fractal dimension may serve as prognostic indicators for endometrial cancer, contributing to the development of more refined screening and diagnostic strategies.

A review of the directly sampled endometrial cytology on LBC samples: Classification, microscopic criteria and beyond

The Yokohama System for Reporting Endometrial Cytology (TYS) has been proposed by an expert meeting under the auspices of the International Academy of Cytology (IAC) in May 2016 at the IAC in Yokohama. Since its introduction, the TYS has been receiving worldwide acceptance, and this review aims to assess its global impact. The adoption of endometrial cytology as a diagnostic procedure has been hampered in the past by difficulties arising in interpreting the cellular findings due to a number of factors (such as excess blood, cellular overlapping and the complex physiology of endometrium). Recently, the use of liquid-based cytology (LBC), with its ability to remove blood and mucus and to distribute cells uniformly in a thin layer on the slide, has provided an opportunity to re-evaluate the role of endometrial cytology. LBC is a useful tool in the cytologic diagnosis and follow-up of endometrial abnormalities, which remains complementary to the emerging molecular diagnostic cytopathology. The study of LBC from endometrial cytology could be challenging since it is affected by numerous look-alikes and diagnostic pitfalls. This review discusses these various entities and takes into consideration the ancillary techniques that may be useful in the diagnostic procedure. In conclusion, our review of the published data suggests that the TYS is a valid classification scheme that has been widely accepted by cytopathologists globally, is highly reproducible and makes a valuable contribution to clinical therapeutic management. At present, molecular cytopathology is a rapidly evolving field of modern cytopathology, which underlines the effective interplay between genomics and cytology. This review aims to provide a comprehensive review of the drawbacks of endometrial cytopathology, particularly in terms of endometrial cancer diagnosis and molecular testing.

Efficacy of the Antigenicity-Retaining Ability of Fixative Solutions for Liquid-Based Cytology: Immunocytochemistry of Long-Term Storage

INTRODUCTION/OBJECTIVE

Liquid-based cytology (LBC) is advantageous as multiple stained specimens can be prepared and used for additional assays such as immunocytochemical and molecular-pathological investigations. Two types of preservative-fixative solutions (fixatives) are used for nongynecologic specimens used in the BD SurePath-LBC (SP-LBC) method, and their components vary. However, few studies have evaluated the differences in antigen-retaining ability between these fixatives. Therefore, we investigated and compared the antigen-retaining ability of the fixatives in immunocytochemical staining (ICC) under long-term storage conditions.

MATERIALS AND METHODS

Sediments of cultured RAJI cells (derived from Burkitt's lymphoma) were added to each fixative (red and blue) and stored at room temperature for a specified period (1 h; 1 week; and 1, 3, and 6 months). The specimens were then prepared using the SP-LBC method and subjected to ICC. Positivity rate was calculated using the specimens fixed at room temperature for 1 h as a control. Antibodies against Ki67 expressed in the nucleus and against CD20 and leukocyte common antigen (LCA) expressed on the cell membrane were used.

RESULTS

For CD20 and LCA, the positivity rate increased with time in the red fixative compared with that in the control. In the blue fixative, the positivity rate was highest at 1 h and was maintained at a high level throughout the storage period. In contrast, the Ki67 positivity rate was highest at 1 h in both red and blue fixatives and markedly decreased with time. Therefore, although refrigerated (8°C) storage was used, no improvement was noted.

CONCLUSIONS

Long-term storage is possible for cell membrane antigens at room temperature; however, it is unsuitable for intranuclear antigens. Therefore, we conclude that suitable fixative type and storage temperature differ based on antigen location. Further investigation is warranted.

An Efficacious Endometrial Sampler for Screening Endometrial Cancer

Recently, the research on early detection of precancerous change and endometrial carcinoma has been focusing on minimally invasive procedures for screening. On this basis, we aim to verify the feasibility of endometrial samplers for screening endometrial cancer using Li Brush. We recruited patients undergoing hysterectomy for different diseases from the Inpatient Department of the Department of Obstetrics and Gynecology. Before surgery, endometrial cells were collected by Li Brush. The cytopathologic diagnosis from Li Brush and the histopathologic diagnosis from hysterectomy in the same patient were compared to calculate sensitivity (Se), specificity (Sp), false-negative rate (FNR), false-positive rate (FPR), positive predictive value (PV+) %, and negative predictive value (PV-). The research enrolled 293 women into this self-controlled trial. According to the hypothesis test of paired four lattices, we obtained the following indicators: Se 92.73, Sp 98.15, FNR 7.27, FPR 1.85, PV+92.73, and PV−98.15%. The endometrial sampler Li Brush is an efficacious instrument for screening endometrial cancer.

Cytological features of uterine carcinosarcoma: A retrospective study of 20 cases with an emphasis on the usefulness of endometrial cytology

BACKGROUND

Carcinosarcoma of the endometrium is a relatively rare but aggressive neoplasm. Endometrial cytological features of this type of tumor have been rarely reported. This study aimed to clarify the usefulness of endometrial cytological examination in the diagnosis of endometrial carcinosarcoma.

METHODS

Patients histopathologically diagnosed with endometrial carcinosarcoma who underwent preoperative endometrial or endocervical cytological examination were enrolled. The endometrial and/or endocervical specimens were conventionally stained with Papanicolaou stain, and the cytological characteristics, including arrangement and shape of the neoplastic cells, and the nuclear and cytoplasmic features were reviewed.

RESULTS

Twenty patients were enrolled in the study. In the endometrial specimens, carcinomatous component was detected in almost all cases (94.4%), including those suspicious of carcinoma despite a small volume of carcinomatous cells. Sarcomatous component was observed in 6 of 18 cases (33.3%) and was significantly more frequently detected in the heterologous type (5 of 9 cases) compared to the homologous type (1 of 9 cases) (P = 0.046). In the endocervical specimens, carcinomatous component was present in 76.5% of cases, but sarcomatous component was detected in only 17.6% of cases.

CONCLUSION

Although endocervical cytology can detect the carcinomatous component in more than 50% of endometrial carcinosarcoma cases, it has lesser capability to detect sarcomatous component. In conclusion, endometrial cytological examination is a more useful and accurate method to detect sarcomatous component of endometrial carcinosarcoma, particularly in the heterologous type, compared to endocervical cytological examination.

Efficacy of liquid-based genetic diagnosis of endometrial cancer

Although liquid-based cytology (LBC) has increased the sensitivity of cytological diagnosis of endometrial cancer (EC) compared with conventional smear cytology, the sensitivity of LBC for the detection of EC is between 70% and 96% and remains unsatisfactory. In the present study, we compared the efficacy of LBC with liquid-based genetic diagnosis (LBGDx) by amplicon sequencing of five genes including PTEN, PIK3CA, CTNNB1, KRAS, and TP53 in 48 LBC subjects who underwent endometrial screening. Consequently, LBC classified 15 samples as "positive or suspicious for malignancy" and the 15 were later confirmed as EC. However, LBC failed to identify five cases who were diagnosed as EC by additional transvaginal ultrasound and endometrial curettage, indicating that the sensitivity of cytology alone was 75% (15/20). LBGDx identified 11 pathogenic PTEN variants in 10 subjects, six PIK3CA variants in nine, three CTNNB1 variants in five, two KRAS variants in four, and three TP53 variants in three. Collectively, at least one pathogenic variant was identified in 19 subjects, which included 17 EC (15 endometrioid carcinoma and 2 endometrial carcinosarcomas), and one cervical adenocarcinoma. However, LBGDx did not identify any pathogenic mutations in three of the 20 EC, indicating that the sensitivity of LBGDx alone was 85% (17/20). Although five EC were negative for malignancy by LBC and three were negative for pathogenic mutations by LBGDx, the combination of LBC and LBGDx would successfully diagnose all 20 EC. These data suggested that LBGDx is a useful strategy to improve the sensitivity of screening of EC by LBC.

Cytological assessment of endometrial washings obtained with Karman cannula using a liquid-based preparation method for the detection of endometrial pathologies

OBJECTIVE

The aim of this study was to evaluate the diagnostic efficacy and utility of liquid-based cytology in ThinPrep (Cytyc Corporation, Boxborough, MA) for endometrial lesions in patients presenting with abnormal uterine bleeding.

MATERIALS AND METHODS

Two hundred and thirteen women scheduled for dilatation and curettage because of abnormal uterine bleeding were enrolled in the study. After providing informed consent, all the women proceeded sequentially to endometrial cytology and then dilatation and curettage.

RESULTS

In the premenopausal group, cytological failure was 4.8%, histopathological failure was 2.4%; cytologic insufficiency in the postmenopausal group was 2.1%, and histopathologic insufficiency was 19.6%. When cytologic and histopathological sufficiency rates were compared in all cases, cytologic insufficiency was 4.2% and histopathologic insufficiency was 6.1%. This difference was statistically significant (p < 0.039). The diagnostic accuracy, sensitivity, specificity, PPV, and NPV of the liquid-based endometrial cytology for premenopausal patients were 96.79, 58.33, 97.92, 70, and 96.58%, respectively. In the postmenopausal cases, the accuracy of diagnosis of endometrial cytology was 97.30%, sensitivity 100%, specificity 96.67%, PPV 87.50%, and NPV 100%. When cytologic and histopathologically inadequate cases were excluded, no cytologic and histopathological abnormal findings were found in endometrial thickness cutoff ≤ 5 mm for all patients.

CONCLUSION

The use of liquid-based cytology with TVS may contribute to increasing the diagnostic accuracy of the test and reduce unnecessary D&C for women. When TVS is used as a triage indicator, regardless of menopausal status in ≤ 5 mm endometrial thickness cases, endometrial cytology is an absolutely reliable method for detecting cancer.

Practical usefulness of atypical endometrial cell categories within the new classification of endometrial cytology when applied to conventional smears

OBJECTIVE

Endometrial cytology has been widely used as a screening tool in Japan. Traditionally, a three-tier reporting system, consisting of 'negative', 'suspicious' and 'positive' categories, has been used. However, a more descriptive system, the New Terminology in Endometrial Cytology (NTEMC), which is based on the Bethesda System for uterine cervical cytology, was introduced recently. The objective of this study was to validate the NTEMC criteria.

METHODS

Endometrial cytology specimens that had been categorised as 'suspicious' were collected in our hospital between 2003 and 2013, and from these, 106 specimens with corresponding histological results, were re-evaluated according to the NTEMC criteria. Diagnostic categories were assigned based on that chosen by the majority of the examining members.

RESULTS

Negative, atypical endometrial cells, of undetermined significance (ATEC-US), atypical endometrial cells for which atypical endometrial hyperplasia or worse cannot be excluded (ATEC-A), endometrial hyperplasia, atypical endometrial hyperplasia and malignancy were selected as the diagnostic categories for 9 (8.5%), 34 (32.1%), 17 (16%), 34 (32.1%), 5 (4.7%) and 7 (6.6%) specimens, respectively. Corresponding histological categories of benign, endometrial hyperplasia, atypical endometrial hyperplasia and malignancy were established in 28 (82.4%), 1 (2.9%), 2 (5.9%) and 3 (8.8%) ATEC-US specimens, respectively, and in 6 (35.3%), 3 (17.6%), 2 (11.8%) and 6 (35.3%) ATEC-A specimens, respectively. The histological category distribution differed significantly (P = 0.001), and there was a significant correlation between corresponding cytological and histological categories (P = 0.005).

CONCLUSION

The ATEC category of NTEMC system works well in a practical setting and resembles the Bethesda reporting system ASC (atypical squamous cells) category for cervical cytology.

Cytological Characteristics of Endometrial Phasing Using the Specimens Prepared with the Liquid-Based Procedure: Comparison with the Conventional Procedure

OBJECTIVE

To evaluate whether or not the liquid-based procedure (LBP) for endometrial cytology is as worthwhile for endometrial phasing as conventional slides.

MATERIALS AND METHODS

The subjects were 81 women who underwent endometrial cytology and were defined as negative. The specimens obtained by either Endocyte® or Masubuchi aspiration tube® were processed first with the conventional procedure and then with LBP using TACAS™.

RESULTS

(1) The number of subjects diagnosed by the conventional method as having proliferative, mid-, middle-secretory and late-secretory and atrophic phases was 40, 11, 10, 0 and 20, respectively. The rate of agreement with those using LBP was 87.7%. (2) Incidences of large clusters, ductal clusters, palisade arrangement, uneven staining and dirty mucous background detected were significantly higher with the conventional method, whereas with LBP clean background, inconspicuous bonding of cells, scattered solitary glandular cells, clear well-stained cytoplasm and cell compactness were higher. (3) Especially in the proliferative phase, clusters tended to be smaller and lose their architectural structures, and scattered solitary columnar cells were present. (4) Cells in the mid-phase tended to have loose contact and to mimic other phases.

CONCLUSIONS

Cytodiagnosis of endometrial phasing prepared with LBP is feasible to perform when some modifications are implemented.

Inter-observer reproducibility of endometrial cytology by the Osaki Study Group method: utilising the Becton Dickinson SurePath™ liquid-based cytology

OBJECTIVE

The purpose of the present study was to evaluate the reproducibility of the cytological diagnosis of endometrial lesions by the Osaki Study Group (OSG) method of new cytological diagnostic criteria using BD SurePath^™ (SP)-liquid-based cytology (LBC).

METHODS

This cytological classification using the OSG method consists of six categories: (i) normal endometrium (NE), (ii) endometrial glandular and stromal breakdown (EGBD), (iii) atypical endometrial cells, cannot exclude atypical endometrial hyperplasia or more (ATEC-A), (iv) adenocarcinoma including atypical endometrial hyperplasia or malignant tumour (Malignancy), (v) endometrial hyperplasia without atypia (EH) and (vi) atypical endometrial cells of undetermined significance (ATEC-US). For this study, a total 244 endometrial samplings were classified by two academic cytopathologists as follows: 147 NE cases , 36 EGBD cases , 47 Malignant cases, eight ATEC-A cases, two EH cases and four ATEC-US cases. To confirm the reproducibility of the diagnosis and to study the inter- and intra-observer agreement further, a second review round followed at 3-month intervals, which included three additional cytopathologists.

RESULTS

The inter-observer agreement of NE classes improved progressively from 'good to fair' to 'excellent', with values increasing from 0.70 to 0.81. Both EGBD and Malignancy classes improved progressively from 'good to fair' to 'excellent', with values increasing from 0.62-0.63 to 0.84-0.95, respectively. The overall intra-observer agreement between the first and the second rounds was 'good to fair' to 'excellent', with values changing from 0.79 to 0.85. All kappa improvements were significant (P < 0.0001).

CONCLUSION

In this study, it seemed that the use of the OSG method as the new diagnostic criteria for SP-LBC preparation, may be a valid method to improve the precision (reproducibility) of endometrial cytology.

Liquid-Based Cytology Preparation Can Improve Cytological Assessment of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

OBJECTIVE

This study investigated whether liquid-based cytology (LBC) can improve diagnostic values of cytological assessment of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).

STUDY DESIGN

A cohort of 600 cases in West China Hospital was prospectively studied from June 2012 to September 2013. EBUS-TBNA was carried out in outpatients under local anesthesia and moderate sedation. The procedure was performed with an echobronchoscope (BF-UC160F-OL8, Olympus, Tokyo, Japan). Histological cores were stained with hematoxylin and eosin for further study. Additional immunohistological analysis was performed for establishing a reliable diagnosis when necessary. Aspirates were smeared on glass slides and separate aspirates were processed by the monolayer SurePath method.

RESULTS

In total, 480 malignant tumors and 120 benign lesions were confirmed by histological examination. The sensitivity of SurePath liquid-based preparations and conventional smears was 82.1 and 56%, and the specificity was 87.5 and 82.5%, respectively. The combined specificity was 100%. Positive predictive values of the two groups were 96.3 and 92.8%, whereas negative predictive values were 54.9 and 31.9%, respectively. The difference between the two groups was significant (p < 0.001).

CONCLUSIONS

LBC preparation can improve cytological assessment of EBUS-TBNA. Histological study is necessary in cases in which the cytological diagnosis is obscure.

Micronucleus evaluation of exfoliated buccal epithelial cells using liquid-based cytology preparation

OBJECTIVE

Micronuclei (MN) are biomarkers that can be applied to buccal epithelial cells to assess populations occupationally exposed to potentially carcinogenic agents. Liquid-based cytology (LBC) is a way to improve and refine the results obtained by this test.

STUDY DESIGN

Exfoliated buccal cells were collected from 40 subjects (20 construction workers from the Barretos Cancer Hospital and 20 administrative staff from the same institution). LBC and three stains (Feulgen/fast green, Papanicolaou and Giemsa) were used to prepare the slides. Student's t test was applied for statistical comparisons of the data. A p value of <0.05 was considered statistically significant.

RESULTS

Regardless of the stain employed, the frequency of MN was greater in the case group (Feulgen/fast green: 5.15; Papanicolaou: 29; Giemsa: 26) than in the control group (Feulgen/fast green: 2.30; Papanicolaou: 17; Giemsa: 15).

CONCLUSIONS

Using LBC to prepare slides and evaluate the frequency of MN potentially serves as a screening option for more comprehensive studies of cancer risk among populations occupationally exposed to potentially carcinogenic agents. In addition, the residual fluid enables the preparation of slides for DNA-specific stains that can be compared to those with Papanicolaou stain.