Tadao K. Kobayashi

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

AbstractIntroductionThis 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.MethodsSP‐LBC specimens were prepared by the following three methods: (1) using the BD PrepMateTM (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.ResultsSignificantly 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.ConclusionsRetention 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

AbstractIntroductionThe 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.ConclusionsCD10 is a very useful immunomarker for distinguishing between G1‐EEC and the metaplastic changes of EGBD in LBC samples.

Evaluation of Diagnostic Accuracy of Directly Sampled Endometrial Cytology Using ThinPrep for Endometrial Malignancies: Comparison With Existing Endometrial Liquid‐Based Cytology

ABSTRACTObjectiveThe aim of this study was to evaluate the accuracy of detecting malignancies by directly sampled endometrial cytology using globally adopted ThinPrep with a novel preparation technique.MethodsMedical records and reports of pathology and cytology from June 2019 to March 2022 were reviewed. We selected 112 endometrial cytology specimens using ThinPrep with the novel preparation technique, where the clinical course or pathological samples confirmed negative or positive results. Eight cytotechnologists or cytopathologists examined the cytology specimens and provided reports based on standardised criteria from the descriptive reporting system for endometrial cytology (the Yokohama System).ResultsThe 112 specimens were evenly smeared and well prepared, featuring high quality, with no issues hindering microscopic examination. Examiners unfamiliar with endometrial cytology using ThinPrep showed high diagnostic accuracy, demonstrating that this modality of preparation for endometrial cytology is feasible for clinical use.ConclusionsThe novel preparation method using ThinPrep successfully provided high‐quality, standardised specimens. Furthermore, employing the Yokohama System enabled high accuracy in detecting endometrial malignancies, even for examiners with minimal experience with this cytological technique. This suggests that ThinPrep‐based endometrial cytology can be globally adopted with ease, potentially contributing significantly to the early detection of endometrial cancer.

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

AbstractThe 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.