Immunohistochemical examination of CD163 and TROP2 expression levels in ovarian endometriosis

Endometriosis is described as an estrogen-associated, chronic, inflammatory disorder characterized by ectopic endometrial glands and stroma. Ovarian endometriosis, or endometrioma, presents as cystic lesions lined by endometrial tissue, with associated fibrosis and inflammation. Although the roles of immune and inflammatory markers in endometriosis have been investigated, the relationship between trophoblast cell surface antigen 2 (TROP2) and CD163 expression in ovarian endometriosis remains unexplored. This study is intended to evaluate immunohistochemical expression degrees of TROP2 and CD163 in ovarian endometriosis compared to normal ovarian tissue. Ovarian tissues from 26 patients with histologically confirmed endometriosis and 26 control subjects were analyzed retrospectively using immunohistochemistry. Semi-quantitative evaluation was performed via H-score analysis. Results showed significantly higher expression of both CD163 and TROP2 in ovarian endometriosis tissues compared to controls. A moderate, positive correlation was observed between CD163 and TROP2 expression. The findings demonstrate, for the first time, increased TROP2 expression in ovarian endometriosis, suggesting a potential role in the disease’s pathophysiology. Additionally, elevated CD163 expression indicates enhanced M2 (alternatively activated) macrophage infiltration, reflecting the inflammatory microenvironment of endometriotic tissue. These results may contribute to understanding the immunopathogenesis of ovarian endometriosis and establish a framework for further research into diagnostic or therapeutic applications targeting TROP2 and CD163.