Immunohistochemical Expression of Estrogen Receptors in Pleomorphic Adenoma and Normal Salivary Gland Tissue

Abstract

Background: The expression of estrogen receptors (ERs) in salivary gland tissue has been observed in some studies. Considering the histological similarity of salivary glands and breast tissue, as well as the prominent role of this receptor in the pathogenesis, treatment, and prognosis of breast tumors, this study aimed to compare the immunohistochemical expression of ERs in pleomorphic adenoma (PA) and normal salivary gland tissue and assess its possible role in salivary gland tumors. Methods: In this descriptive-analytical study, 26 samples of PA (16 females, and 10 males) and 12 samples of normal salivary gland tissue were selected. Immunohistochemical staining was performed by the standard EnVision method for ERs. The results were evaluated semi-quantitively as the percentage of the nuclear and cytoplasmic staining were analyzed independently by Mann-Whitney, Kruskal-Wallis, and Fisher’s exact tests. Results: All PA samples showed negative nuclear staining for ERs. ER expression was observed in the cytoplasm of the ducts in 27% of tumors and 59% of normal salivary gland tissue samples, but the difference was not statistically significant. In addition, no association was found between ER expression and independent variables, such as age, sex, the type of stroma, or the degree of cellularity in PA, and the location of the specimen. Conclusion: It seems that the expression of ERs does not play an effective role in the development and progression of PA. However, its occurrence in the normal salivary gland ducts is considerable, and further studies in this field seem to be necessary.