Structural and cell surface antigen expression in the rete ovarii and epoophoron differs from that in the Fallopian tube and in endometriosis

We compared the immunohistochemical profiles of the rete ovarii and endometriosis in order to identify a panel which distinguishes between these structures. The immune profiles of the epoophoron, Fallopian tube and ovarian surface epithelium were also studied.

Twenty-four women with no evidence of endometriosis and seven who had endometriosis in the uterine adnexae were studied using nine antibodies to intermediate filament proteins and cell surface markers. None of the structures studied shared an identical profile of immunohistochemical reaction. The immunoprofile of endometriosis showed some similarities to that of the Fallopian tube, but differed from that of the rete ovarii, epoophoron and ovarian surface epithelium

A panel including Ca-125, epithelial membrane antigen and the epithelial glycoprotein BerEp4 would permit the distinction between endometriosis and the rete ovarii in problematic cases. The study showed some commonality in reaction between endometriosis and the Fallopian tube which indicates that they may share a common (paramesonephric) origin. There was little commonality in the immunoprofile of endometriosis and the ovarian surface epithelium implying that endometriosis is unlikely to develop as a result of serosal metaplasia.