Utility of thin‐layer preparations in endometrial cytology: Immunocytochemical expression of PTEN, beta‐catenin and p53 for benign endometrial lesions

This article focuses on the characteristic features of morphology and molecular biology of PTEN, beta-catenin, and p53 immunocytochemistry in normal endometrium (proliferative, secretory, and atrophic) and endometrial glandular and stromal breakdown (EGBD) using thin-layer specimens. During a 6-month period, 120 endometrial samples were collected directly using the Uterobrush and a thin-layer specimen was prepared. Immunocytochemical expression of PTEN, beta-catenin, and p53 were investigated using 30 cases each of proliferative endometrium (PE), secretory endometrium (SE), atrophic endometrium (AE), and EGBD.PTEN expression of normal endometrial glandular epithelial cells changes with the hormonal status; PE produce very high expression, SE creates attenuation or disappearance of PTEN expression and AE diminished more in comparison with SE. PTEN expression of EGBD showed a tendency towards attenuation compared with PE, but showed high expression in comparison with SE and AE. As for the immunoreactivity of beta-catenin, in all phases (PE, SE, AE, and EGBD), it was observed in the cytoplasm of glandular epithelial cells, but not nuclei, and showed strong membranous staining. As for the p53 immunoreactivity, p53 positivity was not observed in the glandular epithelial cells in all phases (PE, SE, AE, and EGBD) with the exception of some metaplastic cells. The presence of p53 immunoreactivity of a weak, low ratio in metaplastic cells was unexpected. In the current study, the expression manner of PTEN, beta-catenin, and p53 immunocytochemistry was observed in the normal endometrium (PE, SE, and AE) and EGBD.