Insulin‐like growth factor‐II mRNA‐binding protein 3 immunocytochemical expression in direct endometrial brushings: Possible diagnostic help in endometrial cytology

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.

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.

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.

Nuclear morphometry as an adjunct to cytopathologic examination of endometrial brushings on LBC samples: A prospective approach to combined evaluation in endometrial neoplasms and look alikes

OBJECTIVE

In this study, we aimed to retrospectively investigate and confirm whether atypical nuclear findings in endometrial cytology are useful when assessed by image morphometry in liquid-based cytology (LBC) and compared with microscopic evaluation.

METHODS

In total, 53 cases were selected for this study, including 11 presenting proliferative endometrium, 12 with surface papillary syncytial change with endometrial glandular and stromal breakdown (EGBD-SPSC), 10 endometrioid carcinoma grade 1 (G1-EEC), 10 EEC grade 3 (G3-EEC), and 10 endometrial serous carcinomas (ESC). Nuclear image morphometry for nuclear geometric features (area, grey value, aspect ratio, internuclear distance, nucleolar diameter) was performed using ImageJ computer software. For assessing nucleoli, 3861 nuclei were measured, and for nuclear findings, except for nucleoli, 4036 nuclei were measured in total.

RESULTS

(a) Compared with G1-EEC, G3-EEC and ESC presented a marked increase in all six parameters (nuclear enlargement, anisonucleosis, nuclear shade, nuclear shape, irregularity of nuclear arrangement, and nucleolar size). (b) EGBD-SPSC presented a marked increase in two parameters (nuclear shade, nuclear shape) when compared with G1/G3-EEC and ESC. (c) Compared with EGBD-SPSC, EEC and ESC demonstrated a marked increase in nucleolar size (≥2.0 μm). (d) ESC presented a marked increase in nucleolar size (≥3.0 μm) when compared with G3-EEC.

CONCLUSIONS

Here we confirmed that atypical nuclear findings evaluated by image morphometry are as useful as microscopic evaluations in endometrial cytology. We believe that the objective evaluation of nucleolar size could contribute to an accurate diagnosis of endometrial-LBC samples.

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

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 reevaluate the role of endometrial cytology. LBC samples are easier to screen compared to conventional ones, due to a smaller screening area and an excellent quality of cell preparations. LBC by using peculiar cytoarchitectural features is a useful tool in the cellular diagnosis and follow-up of abnormalities, which, however, remains complementary to histopathology and to the emerging molecular diagnostic cytopathology. This review discusses these various entities and takes into consideration the ancillary techniques that may be useful in the diagnostic procedure. Herein, we also summarize the process and rationale by which updates were made to the standardized terminology in 2018 and outline the contents of the new Bethesda-style classification (the Yokohama system) for the endometrial cytology.