Mesonephric carcinosarcoma involving uterine cervix and vagina: report of 2 cases with immunohistochemical positivity For PAX2, PAX8, and GATA-3.

Mesonephric carcinomas are rare tumors predominantly arising in the uterine cervix from mesonephric remnants. Although the tumor has classic morphologic features, some cases can mimic Müllerian adenocarcinoma and be misdiagnosed, especially those with significant ductal pattern. Moreover, there is an overlap in immunohistochemical results with endometrial and endocervical carcinomas. In this study, we report 2 cases of mesonephric carcinosarcoma, originally diagnosed as Müllerian carcinomas, 1 presenting in the vagina; review immunohistochemical results including positivity for GATA-3, not previously reported and comment on the proposed panel of PAX8, p16, and estrogen receptors as discriminators of Müllerian adenocarcinoma (endocervical or endometrial) versus mesonephric carcinoma.