Morphological Differences between Liquid-Based Cytology and Conventional Preparation in Endometrial Endometrioid Carcinoma Grade 1 and Grade 3, and the Differentiation of Grades in Each Method

Abstract

Introduction: Direct smearing preparation (conventional preparation [CP]) has been widely used for endometrial cytology in Japan. In CP, sampling and screening errors are problematic. In liquid-based cytology preparation (LBC), the problems of CP can be solved. But there is a problem that cytological findings of LBC are different from those of CP. The purpose of this study was to evaluate the differences of morphological findings of endometrial cytology between LBC and CP, and the usefulness of the endometrial LBC to differentiate endometrioid carcinoma grade 1 (G1) from grade 3 (G3). Methods: Thirteen cases of endometrioid carcinoma G1, and 5 cases of G3 collected by the Softcyte device and prepared by LBC and CP (split specimen) were used. We focused on the following items: (1) the number of clusters per cm2, (2) the number of layers of clusters, (3) area of clusters, (4) perimeter of clusters, (5) roundness of clusters, (6) complexity of clusters, (7) area of nucleus, (8) perimeter of nucleus, (9) roundness of nucleus, (10) complexity of nucleus, (11) area of nucleolus, and (12) nucleolus-nucleus ratio (N/N). Results: Compared with CP, the number of clusters and layers of the clusters in LBC were significantly larger in G1. The area and perimeters of the clusters and the nucleus were significant smaller, and the N/N ratio was greater in LBC than that in CP in both G1 and G3. Regarding morphological differences between G1 and G3 in LBC and CP, the number of layers was significantly larger in G1 than in G3 in LBC and CP. The area of the clusters in LBC was significantly larger in G1 than in G3. The area and perimeters of the nucleus in CP and the area of the nucleolus and N/N ratio in LBC and CP were significantly smaller in G1 than in G3. Conclusion: In the endometrial cytology, it became clear that the cell image was different between LBC and CP and between G1 and G3. By microscopic examination understanding the characteristics of the cell image in LBC, endometrial LBC could be useful to diagnose endometrial carcinoma.

Morphometrical Differences among Endometrial Endometrioid Carcinoma Grade 1, Grade 3, and Serous Carcinoma in Endometrial Liquid-Based Cytology Preparations

“…The roundness of cluster was G1>G3 and G1>Serous, and the complexity of cluster was G1<G3 and G1<Serous, both showing significant differences. By image analysis of endometrial LBC (SurePath) specimens collected with Softcyte, although the differences were not significant between the grades of EC, a tendency similar to the results of our present study was observed [20]. The roundness was higher in G1 than in G3, and the complexity was higher in G3 than in G1, probably reflecting that G1 consists of rounder papillary clusters and that G3 consists of more complex clusters, which are loosened due to weakened cell binding.…”

“…There is a report that the N/N ratio between G1 and G3 was G1<G3. In this report, the N/N ratio was G1 (0.056 ± 0.002)<G3 (0.068 ± 0.002), because the area of nucleus was nearly the same between G1 and G3 due to the marked nuclear shrinkage in G3 while the size of nucleolus was G1<G3 [20]. The N/N ratio between G3 and Serous was G3<Serous because the nucleus enlargement rate of Serous relative to G3 was 1.30 (70.9/54.6), but the nucleolus enlargement rate was higher at 1.43 (4.70/3.27).…”

“…The diameter of nucleolus has also been reported to be G1<G3<Serous [19]. There is also a similar report that the area of nucleolus was G1 (2.57 ± 0.08 μm 2 )<G3 (3.27 ± 0.12 μm 2 ) [20]. In our present study, also, the size of nucleolus differed widely among the histological types, and as it can be readily evaluated by microscopy, it is considered to contribute to the differential determination of histological types.…”

“…Using the whole slide image preparation systems TOCO or FINO (Path Imaging, Tokyo, Japan), each cell cluster was photographed by multilayer scanning under the conditions of an object lens magnification ×40, Z axis layer thickness of 0.25 μm, and maximum light intensity (255). In all the images obtained, (1) number of layers of cluster, (2) area of cluster (µm 2 ), ( 3) perimeter of cluster (µm), (4) roundness of cluster, (5) complexity of cluster, (6) area of nucleus (µm 2 ), (7) perimeter of cluster (µm), ( 8) roundness of nucleus, (9) complexity of nucleus, (10) 11) nucleolus/nucleus ratio (N/N) were measured as in a previous study [20].…”

“…However, by these methods, malignant neoplasms are lumped together as adenocarcinoma, and histological distinction among different grades of EC and Serous is not made. Recently, morphological differences of the nucleus and nucleolus in G1, G3, and Serous by image analysis using endometrial LBC specimens collected by the brush [19] and morphological differences of the cell cluster, nucleus, and nucleolus in G1 and G3 by image analysis using endometrial LBC specimens collected by the Softcyte device [20] have been reported. We, therefore, conducted this study to objectively clarify morphometrical differences of the cell cluster, nucleus, and nucleolus of G1, G3, and Serous in endometrial LBC by analyzing whole slide images.…”