Comparison of immunohistochemical characteristics of endometriomas with non-endometriotic benign ovarian cysts

The aim of the study was to investigate the existence of neuroendocrine cells and to compare the density of those in normal ovarian tissue, endometriotic and non-endometriotic benign ovarian cysts.

Twenty patients with the diagnosis of endometrioma and 30 control subjects consisting of ovarian serous cystadenoma (n=10), ovarian mucinous cystadenoma (n=10) and normal ovarian tissue (n=10) were included. The tissues were prepared and assessed according to staining density by using the H-score method.

Tissues with mucinous cystadenoma were significantly more stained with PAS and VanGieson, when compared to women with endometrioma. Macrophage deposition was higher in cyst samples with endometrioma and in normal ovarian tissue when compared to serous cystadenoma and mucinous cystadenoma. Normal ovarian tissue was significantly more stained with PGP9.5, NSE and SYN when compared to endometrioma and non-endometriotic benign ovarian cyst. PGP9.5 staining was higher in normal ovarian tissue when compared with endometriotic lesions (p<.001). Endometrioma samples were significantly more stained with p53 when compared to non-endometriotic cysts and normal ovarian tissue. c-Kit staining was mild and not statistically significant among all groups.

During endometrioma transformation, expression intensity of neuroendocrine markers decreases compared to normal ovarian tissue and other benign ovarian cysts.