Histopathologic evaluation of the inflammatory factors and stromal cells in the endometriosis lesions: A case-control study

Endometriosis is a multifaceted gynecological disorder defined as a benign estrogen-dependent chronic inflammatory process in which endometrial glands and stroma-like tissues are located outside the uterine cavity. It affects around 2-10% of all women during their reproductive years.  

This study aimed to evaluate the traffic of mesenchymal stem cells and inflammatory factors toward the lesions.

10 samples of normal endometrium and eutopic endometrium were studied as a control group and 10 ectopic samples were considered as a case group. Hematoxylin and eosin staining was used to evaluate stromal cells and inflammatory cells. Immunohistochemical staining was performed to show the presence of proliferating cell nuclear antigen in the lesions. The cells were digested and cultured in the laboratory to study cell proliferation. The number of cells and vessels were counted with Image J software, and data analysis was performed with Prism software.

Data analysis showed that the number of stromal cells and vessels in ectopic tissue were significantly higher than the control group (p < 0.001). Also, the number of inflammatory cells, including neutrophils, monocytes, lymphocytes, and macrophages, in the ectopic group was much higher than in the control group (p < 0.005).

By expanding the number of blood vessels, blood flow increases, and cell migration to tissues is facilitated. The accumulation of inflammatory cells, especially macrophages, stimulates the growth of stem cells and helps implant cells by creating an inflammatory process.