Endometrial cytopathology. An image analysis approach using the Ki-67 biomarker

To investigate the different identity and biological behaviour of endometrial benign epithelial and endometrial adenocarcinoma cell categories.

For this study, the imprint smears from three groups, 10 cases of disordered proliferative/benign hyperplastic endometrium, 21 cases of low-grade and eight cases of high-grade endometrial adenocarcinoma, were examined using image analysis and the Ki-67 biomarker. The plastic stem cell model was also applied.

Among the examined groups, the nuclear area major axis ranged statistically different in the digitally measured Ki-67 positive endometrial epithelial and adenocarcinoma cells (P<.0001). Moreover, higher values of the cycling nuclear area major axis were observed in high-grade, as compared with the low-grade endometrial adenocarcinomas (P<.0001) and the cases of disordered/benign hyperplastic endometrium (P<.0001). Additionally, a Ki-67 increase pathway was observed in the benign endometrial lesions, and a relatively stable pathway was noticed in low- and high-grade endometrial adenocarcinomas.

The different range of the nuclear area major axis among cycling endometrial epithelial and adenocarcinoma cells may correlate with their specific identity and biological behaviour. The different values of the cycling nuclear area major dimension may also be connected with the biological behaviour of the three examined groups. Moreover, the endometrial epithelial cells may follow a Ki-67 increase pathway, instead of the relatively stable pathway which the rapidly proliferating adenocarcinoma cells may use. Finally, the studied cell categories may exhibit different biology, because their stem cells may reside in different states of stemness.