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

Staining Pattern of Alcian Blue in Endometrial Cytology: Utility in Distinguishing Grade 1-Endometrial Endometrioid Carcinoma from Endometrial Glandular Stromal Breakdown

Background and Objective

In endometrial cytology, differentiating endometrial glandular stromal breakdown (EGBD) from endometrial endometrioid carcinoma (G1-EEC) is often difficult. In this study, we provided a new focus on chondroitin sulfate (CS), a major substrate component of the endometrial stroma, and assessed the diagnostic utility of Alcian Blue (AB) staining in the differential diagnosis in liquid-based cytological (LBC) samples.

Materials and Methods

LBC specimens from 19 patients with a proliferative endometrium, 36 with EGBD, and 30 with G1-EEC who underwent endometrial cytology were stained with AB (pH 1.0), and their reactivity was observed. In addition, immunocytochemical staining of CS and CD31 was performed for five cases each to evaluate their interrelationship with blood vessels.

Results

Regarding the 30 G1-EEC cases, at least one of the three representative staining patterns was observed by AB staining: dot-like, microtubular, and finely branched linear patterns. Moreover, the inner portion of the tubular material observed by AB staining expressed CD31. Conversely, in the 36 EGBD cases, only five metaplastic clusters with irregular protrusions and condensed stromal clusters (CSCs) showed a dot-like positive pattern, and background CSCs did not show reactivity to AB staining in any of the cases. Furthermore, the vascular structure expressing CD31 in cell clusters was also unclear.

Conclusions

We demonstrated that AB staining shows different staining patterns in G1-EEC and EGBD, reflecting their different tissue structures. Our data provide new insights into endometrial cell diagnosis changes and demonstrate that AB staining is a potential new diagnostic aid tool for the differentiation of G1-EEC from EGBD.

Novel cytological model for the identification of early oral cancer diagnostic markers: The carcinoma sequence model

Most oral squamous cell carcinomas (OSCCs) arise from a premalignant lesion, oral epithelial dysplasia; however, useful markers for the early detection of OSCC are lacking. The present study aimed to establish a novel experimental model to observe changes in the sequential expression patterns of mRNAs and proteins in a rat model of tongue cancer using liquid-based cytology techniques. Cytology specimens were collected at 2, 5, 8, 11, 14, 17 and 21 weeks from rats treated with 4-nitroquinoline 1-oxide to induce tongue cancer. The expression of candidate biomarkers was examined by performing immunocytochemistry and reverse transcription-quantitative PCR. The percentage of positively stained nuclei was calculated as the labeling index (LI). All rats developed OSCC of the tongue at 21 weeks. The mRNA expression levels of bromodomain protein 4 (Brd4), c-Myc and Tp53 were upregulated during the progression from negative for intraepithelial lesion or malignancy to squamous cell carcinoma (SCC). Brd4- and c-Myc-LI increased in low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion and SCC specimens. p53-LI was significantly increased in SCC specimens. This novel experimental model allowed the observation of sequential morphological changes and the expression patterns of mRNAs and proteins during carcinogenesis. Combining immunocytochemistry with cytology-based diagnoses may potentially improve the diagnostic accuracy of OSCC.

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.

Microscale endometrial sampling biopsy in detecting endometrial cancer and atypical hyperplasia in a population of 1551 women: a comparative study with hysteroscopic endometrial biopsy

BACKGROUND

Endometrial cancer is one of the most common malignancies of the reproductive system. Effective and cost-effective screening method for populations at high risk is not available. This study aimed to investigate specimen adequacy and the influencing factors in microscale endometrial sampling biopsy and to evaluate the diagnostic accuracy and medical cost of biopsy in endometrial cancer and atypical hyperplasia screenings in comparison with hysteroscopic endometrial biopsy.

METHODS

A total of 1551 patients at high risk for endometrial lesions who required hysteroscopic endometrial biopsy from November 2017 to August 2018 were included. Microscale endometrial sampling biopsy was performed, followed by hysteroscopic endometrial biopsy. We evaluated the specimen adequacy and influencing factors of microscale endometrial sampling. Diagnostic consistency between microscale endometrial sampling biopsy and hysteroscopic endometrial biopsy was evaluated. The sensitivity, specificity, positive predictive value, and negative predictive value of microscale endometrial sampling biopsy in screening for endometrial cancer and atypical hyperplasia were analyzed, and the medical costs of the two procedures were compared.

RESULTS

The specimen adequacy was 81.2%. Patient age, menopausal status, endometrial thickness, and endometrial lesion type were correlated with specimen adequacy. There was good consistency in distinguishing benign and malignant endometrial diseases between microscale endometrial sampling biopsy and hysteroscopic biopsy (kappa 0.950, 95% CI 0.925-0.975). The sensitivity, specificity, positive predictive value, and negative predictive value of microscale endometrial sampling biopsy were 91.7%, 100.0%, 100.0%, and 99.3% for endometrial cancer screening, respectively, and 82.0%, 100.0%, 100.0%, and 99.4% for atypical hyperplasia screening. The medical cost of endometrial sampling biopsy was only 22.1% of the cost of hysteroscopic biopsy.

CONCLUSIONS

Microscale endometrial sampling biopsy is a minimally invasive alternative technique for obtaining adequate endometrial specimens for histopathological examination. It has the potential to be used in detecting endometrial cancer and atypical hyperplasia with high efficiency and low cost.

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.

Evaluation of the benefit and use of the new terminology in endometrial cytology reporting system

OBJECTIVE

The introduction and establishment of a new classification system for endometrial cytology, the "New Terminology in Endometrial Cytology (NTEMC) system," which is based on the Bethesda System for uterine cervical cytology, has recently been reported. However, the clinical management for new categories in the NTEMC system, particularly atypical endometrial cells (ATEC), has not been clarified. The objective of the present study is to determine how the ATEC category should be treated and whether the introduction of the system has decreased the number of unnecessary endometrial biopsies.

METHODS

Fifty-nine cases were diagnosed as "suspicious positive" according to the three-tier reporting (TTR) system, which was adopted in Japan. The specimens were re-evaluated according to the NTEMC system. Thirty-seven of the 59 patients underwent endometrial biopsy. We correlated the pathological diagnosis with the NTEMC system category.

RESULTS

The 59 cases were classified according to the NTEMC system as follows: 36 cases were classified as ATEC of undetermined significance (ATEC-US), 21 cases were classified as ATEC for which atypical endometrial hyperplasia or worse cannot be excluded (ATEC-A), and 2 cases were classified as endometrial hyperplasia. The ratio of atypical endometrial hyperplasia or malignancy in ATEC-US category was significantly lower than that in ATEC-A category. Fifteen cases in ATEC-US category did not show atypical endometrial hyperplasia lesions or malignancy after 3 months.

CONCLUSIONS

These data suggest that patients with ATEC-US results can be followed up for at least three months, and the introduction of the NTEMC system decreased the number of unnecessary endometrial biopsies.

Internal quality control in an academic cytopathology laboratory for the introduction of a new reporting system for endometrial cytology

BACKGROUND

To evaluate reproducibility of a reporting system for endometrial cytology.

METHODS

Cytologic slides from 49 patients, prepared via liquid based cytology, were blindly examined by five cytopathologists of various experience levels, applying a recently introduced reporting system as previously reported. The agreement among cytopathologists was evaluated via Kappa (κ) statistics and the Kendall's Coefficient of Variation (W); cytologic results were compared with the relevant histologic report.

RESULTS

Substantial agreement among all five raters was found in the benign, ACE-L and malignant categories, fair agreement in inadequate and ACE-H categories, whereas only slight agreement in ACE-U. For the three more experienced cytopathologists, an almost perfect agreement was found in inadequate, benign, and ACE-L categories, substantial agreement in ACE-H and malignant categories and fair agreement in ACE-U category. Overall agreement for all five cytopathologists and for all categories was moderate, whereas it was very high for the three senior raters. Using the Kendall's test, both five cytopathologists (W = 0.81) and the three senior ones (W = 0.93) had very high agreement. Sensitivity: 83.33-92.59%, specificity: 83.33-94.74%, ROC area: 71.72-90.3%.

CONCLUSION

Application of appropriate statistical tests shows that integration of a new reporting cytologic system is effective with an overall accuracy around 90%. Both statistical tests applied disclosed lower agreement rates among both all five raters and the three most experienced ones in the intermediate categories constituting the gray zone, thus delineating the need for better training of cytopathologists to correctly identify diagnostic criteria for classification of a given case into these categories.