A Diagnostic Approach to Endometrial Cytology by Means of Liquid-Based Preparations

Utility of Pipet Curet Cytology and Biopsy as a Diagnostic Method for Endometrial Endometrioid Carcinoma

INTRODUCTION

We aimed to determine the utility of Pipet Curet cytology (PCC) and Pipet Curet biopsy (PCB) for diagnosing uterine endometrial endometrioid carcinoma (EEC).

METHODS

We divided 77 patients with EEC into two groups per Federation of Gynecology and Obstetrics (FIGO) grades: G1 (n = 44) and G2/3 (n = 33) and compared the diagnostic sensitivity of PCC, PCB, and PCC and PCB combined, retrospectively. Next, we investigated any diagnostic discordance between PCC-based and PCB-based diagnoses per FIGO grade group.

RESULTS

The diagnostic sensitivity of PCC, PCB, and the two modalities combined was significantly higher for G2/3 EECs than for G1 EECs (72.7% vs. 45.5%, p = 0.0209; 84.8% vs. 63.6%, p = 0.0434; and 93.9% vs. 65.9%, p = 0.0046, respectively), likely due to more friable cancer cells in higher grade EEC cases. Among our 77 EEC patients, there were 4 patients (5.19%) with PCC-based concordant but PCB-based discordant results against EEC, in the G2/3 group predominantly. Diagnostic sensitivity of all cases increased from 72.7% (56/77) by PCB alone to 77.9% (60/77) by use of both modalities combined.

CONCLUSION

Cytologic evaluation can reduce the number of false-negative histologic diagnoses. By providing complementary information, the two modalities combined from the Pipet Curet procedure would be valuable as a diagnostic method for EEC.

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.

Endometriosis first presenting in pleural fluid cytology

Most patients with thoracic endometriosis present with catamenial pneumothorax, a rare condition in which recurrent episodes occur within 72 h before or after the start of menstruation. We report a case of thoracic endometriosis presenting with recurrent bloody pleural effusions without pneumothorax diagnosed on pleural fluid cytology. We describe the cytomorphology and immunoprofile of thoracic endometriosis and discuss the differential diagnoses, including neoplastic processes. We also highlight the importance of communication with clinicians for timeliness of diagnosis and treatment, especially when thoracic endometriosis is not suspected.

Endometrial Cytology in Diagnosis of Endometrial Cancer: A Systematic Review and Meta-Analysis of Diagnostic Accuracy

BACKGROUND

Because the incidence of endometrial cancer has been increasing every year, it is important to identify an effective screening method for it. The endometrial cytology test (ECT) is considered to be the more acceptable technique compared to invasive endometrial sampling.

METHODS

The study followed the Priority Reporting Project for Systematic Evaluation and Meta-Analysis (PRISMA-DTA) protocol. This systematic rating searched EMBASE and Web of Science databases for studies on ECT for endometrial cancer from the databases' dates of inception to 30 September 2022. All literature screening and data extraction were performed by two researchers, while the methodological quality of the included studies was assessed against defined inclusion criteria. And a third researcher resolves the disagreements.

RESULTS

Twenty-six studies were eventually included in this final analysis. Meta-analysis results showed that the diagnostic accuracy characteristics of ECT for endometrial cancer were as follows: combined sensitivity = 0.84 [95% confidence interval (CI) (0.83-0.86)], combined specificity = 0.98 [95% CI (0.98-0.98)], combined positive likelihood ratio = 34.65 [95% CI (20.90-57.45)], combined negative likelihood ratio = 0.21 [95% CI (0.15-0.30)], and area under the summary receiver operating characteristic curve = 0.9673.

CONCLUSIONS

ECT had the ability to detect endometrial cancer with strong specificity, although some studies have demonstrated significant differences in sensitivity.

Diagnostic value of endometrial cytology and related technology

BACKGROUND

Endometrial cytology is not much popular in the world, but is commonly used in a few countries. Although cytomorphological evaluation of endometrial cytology is complicating, recent advance in technology helps improve diagnostic accuracy. In addition, new reporting system, The Yokohama System, has been introduced as a standard reporting system resembling The Bethesda System of the uterine cervical cytology. Although sample standardization is one of the causes in diagnostic problem, it was solved by liquid-based cytology (LBC) technology. In addition, standardized diagnostic algorithm by cytomorphological assessment of LBC samples, the Osaki Study Group (OSG) method, was recently proposed as a reliable and reproducible method. LBC can be utilized for ancillary methods. Application of immunocytochemistry and molecular technology on endometrial cytology samples has been studied to improve diagnostic accuracy. Recent progress of molecular technology has revealed many driver gene mutations in endometrial cancer and its precursors. Surprisingly, many studies revealed that even normal endometrial tissue had driver gene mutations.

CONCLUSION

Based on the recent advance in knowledge of molecular profile of endometrial lesions and normal endometrial tissue, endometrial cytology will gain much power in clinical usefulness.

A study on preserving endometrial glandular architecture during preparation using BD SurePath™ liquid-based cytology reagents: Cellular fixation with preservative fluid requires at least 18 h

INTRODUCTION

This study aimed to determine the causes of disruption of the three-dimensional architecture of endometrial glands prepared using BD SurePath™ liquid-based cytology (SP-LBC) reagents. One sample preparation method for endometrial cytology is presented in which this three-dimensional architecture can be retained.

METHODS

SP-LBC specimens were prepared by the following three methods: (1) using the BD PrepMate^TM (PrepMate) System after cellular fixation for 1-6 h (method A); (2) without using the PrepMate System after cellular fixation for 1-6 h (method B); and (3) using the PrepMate System after cellular fixation for at least 18 h (method C). Size and numbers of endometrial cell clusters and numbers of solitary scattered cells were then evaluated.

RESULTS

Significantly higher numbers of cell clusters with a major axis of 200 μm or more were yielded by method C (71.3 ± 57.2) than methods A (9.3 ± 5.9, P < 0.001) or B (44.3 ± 28.8, P < 0.05). Method B yielded significantly higher numbers of cell clusters than method A (P < 0.001). Method A (132.2 ± 107.7, p < 0.001) yielded significantly higher numbers of solitary scattered cells than methods B (29.1 ± 14.8) and C (35.7 ± 23.3). No significant difference in solitary cell numbers was found between methods B and C.

CONCLUSIONS

Retention of endometrial glandular architecture is rendered possible by allowing sample fixation times of 18 h or more when preparing specimens using the PrepMate System.

The expression pattern of CD10 and CD31 identifies fine fibrovascular stroma of grade 1-endometrial endometrioid carcinomas in cytology

INTRODUCTION

The objective of this study was to assess the diagnostic utility of CD10 in the differential diagnosis of grade 1-endometrial endometrioid carcinoma (G1-EEC) and the metaplastic changes associated with the endometrial glandular and stromal breakdown (EGBD) on liquid-based cytological (LBC) samples.

METHODS

(1) The type and distribution of CD10-positive cells in EGBD and G1-EEC patients were evaluated. (2) Based on the results from (1), histological and cytological specimens were double-immunostained with CD31 and CD10 to confirm whether CD10-positive tubular-canalicular material found in (1) was represented by fine threads of endometrial-type fibrovascular stroma. (3) Based on the results from (2), additional immunostaining of histological specimens was performed for CD146 and αSMA as markers of perivascular cells.

RESULTS

(1) CD10 positive cells showed two main patterns of expression: cytoplasmic immunoreactivity in the form of dense brown granules in EGBD and tubular-canalicular branching patterns in G1-EEC. (2) The tubular-canalicular material observed in cytological specimens of G1-EEC samples co-expressed CD10 and CD31, and was interpreted as representing fine threads of endometrial fibrovascular stroma in the corresponding histological samples. Conversely, metaplastic changes in EGBD cases, only a few CD31-positive signals were found inside the condensed stromal clusters with CD10-positive. (3) Cells surrounding the CD31-positive vascular endothelial cells expressed CD146 and αSMA; moreover, some of the thin CD10-positive fibrous stromal strands also co-expressed αSMA.

CONCLUSIONS

CD10 is a very useful immunomarker for distinguishing between G1-EEC and the metaplastic changes of EGBD in LBC samples.

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.

Direct next-generation sequencing analysis using endometrial liquid-based cytology specimens for rapid cancer genomic profiling

BACKGROUND

Genomic examination of cytology specimens is often performed on cell blocks or conventional smears rather than on liquid-based cytology (LBC) specimens. Since LBC specimens preserve high-quality DNA, cancer genome profiling using next-generation sequencing (NGS) is also attainable from residual LBC specimens. One of the advantages of using LBC specimens for NGS is that it allows direct extraction of DNA from residual specimens, avoiding a sacrifice of smear slides and minimizing genomic profiling processing time.

METHODS

Endometrial LBC specimens were subjected to NGS analysis to validate the practicality of rapid cancer genomic profiling in a pathology laboratory. The extracted DNA was subjected to NGS using a customized cancer gene panel comprising 56 genes and 17 microsatellite regions. The workflow strategy was defined, and the processing time estimated for specimen sampling, cell counting, NGS run, and genome profiling.

RESULTS

NGS analysis of most LBC specimens revealed somatic mutations, tumor mutation burden, and microsatellite instability, which were almost identical to those obtained from formalin-fixed paraffin-embedded tissues. The processing time for direct NGS analysis and cancer genomic profiling of the residual LBC specimens was approximately 5 days.

CONCLUSION

The residual LBC specimens collected using endometrial cytology were verified to carry a high tumor fraction for NGS analysis and could serve as an alternate source for rapid molecular classification and diagnosis of endometrial cancers, as a routine process in a pathology laboratory.

Methodologies of Primary HPV Testing Currently Applied for Cervical Cancer Screening

The human papillomavirus is one of the most common sexually transmitted viruses, and an infection from this virus may become persistent, leading to diseases such as cervical cancer. In the past, cytology-based methods such as the Papanicolaou (Pap) test were imperative to identify the disease at a stage where it can be treated. However, since the 1980s where the etiological association of HPV and cervical cancer was identified, new tests began emerging directed towards identifying the virus. Furthermore, as the biology of HPV along with the relationships with its host are elucidated, these tests and treatments further advance. Recently in Europe, there is a movement towards the implementation of HPV testing methodologies in national screening programs to precede cytological testing. These screening strategies are recommended by the European guidelines and the World Health Organization. This review presents the current HPV testing methodologies, their application in organized population-based cervical cancer screening programs based on the most recent European guidelines, and their implementation status in countries in Europe.

Next-generation sequencing analysis of endometrial screening liquid-based cytology specimens: a comparative study to tissue specimens

Background

Liquid-based cytology (LBC) is now a widely used method for cytologic screening and cancer diagnosis. Since the cells are fixed with alcohol-based fixatives, and the specimens are stored in a liquid condition, LBC specimens are suitable for genetic analyses.

Methods

Here, we established a small cancer gene panel, including 60 genes and 17 microsatellite markers for next-generation sequencing, and applied to residual LBC specimens obtained by endometrial cancer screening to compare with corresponding formalin-fixed paraffin-embedded (FFPE) tissues.

Results

A total of 49 FFPE and LBC specimens (n = 24) were analyzed, revealing characteristic mutations for endometrial cancer, including PTEN, CTNNB1, PIK3CA, and PIK3R1 mutations. Eight cases had higher scores for both tumor mutation burden (TMB) and microsatellite instability (MSI), which agree with defective mismatch repair (MMR) protein expression. Paired endometrial LBC, and biopsied and/or resected FFPE tissues from 7 cases, presented almost identical mutations, TMB, and MSI profiles in all cases.

Conclusion

These findings demonstrate that our ad hoc cancer gene panel enabled the detection of therapeutically actionable gene mutations in endometrial LBC and FFPE specimens. Endometrial cancer LBC specimens offer an alternative and affordable source of molecular testing materials.