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

Aims: We compared the immunohistochemical profiles of the rete ovarii and e ndometriosis in order to identify a panel which distinguishes between these structures. The immune profiles of the epoophoron. Fallopian tube and ovar ian surface epithelium were also studied. Materials and methods: Twenty-four women with no evidence of endometriosis and seven who had endometriosis in the uterine adnexae were studied using n ine antibodies to intermediate filament proteins and cell surface markers. None of the structures studied shared an identical profile of immunohistoch emical reaction. The immunoprofile of endometriosis showed some similaritie s to that of the Fallopian tube, but differed from that of the rete ovarii, epoophoron and ovarian surface epithelium Conclusions: A panel including Ca-125, epithelial membrane antigen and the epithelial glycoprotein BerEp4 would permit the distinction between endomet riosis and the rete ovarii in problematic cases. The study showed some comm onality in reaction between endometriosis and the Fallopian tube which indi cates that they may share a common (paramesonephric) origin. There was litt le commonality in the immunoprofile of endometriosis and the ovarian surfac e epithelium implying that endometriosis is unlikely to develop as a result of serosal metaplasia.