Mesonephric Adenocarcinoma Arising From The Uterine Corpus：Case Reports and Literature Review

Abstract

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Background</jats:bold> Mesonephric adenocarcinoma (MNAC) is a rare carcinoma which arises from the mesonephric remnant of the gynecologic tract. It mainly occurs in the uterine cervix, barely locates in the uterine corpus, ovarian and vagina. To date, only a few cases of MNAC arising from of the uterine body (UB-MNAC) have been reported, and the clinicopathologic and molecular characteristics of UB-MNAC remain limited. A recent report suggested that series of UB-MNAC should be defined as Mesonephric-like adenocarcinoma carcinomas (MLAC), for they exhibited the classic morphologic features and immunophenotype of mesonephric carcinoma, but occurring outside of the cervix and without convincing mesonephric remnants. Thus, the histogenesis of UB-MNAC is not yet clear, they may originate in Müllerian tissue and exhibits the mesonephric differentiation phenotype, or arise from the mesonephric remnants in the uterine wall.<jats:bold>Case presentation </jats:bold>To better understand the histogenesis of UB-MNAC, we presented three UB-MNAC cases from west china second university hospital, which exhibited typical morphologic, histologic as well as the immunohistochemical characteristics of MNAC. Notably, among the three cases, two cases arising from the myometrium layer of the uterine corpus found mesonephric remnants around the tumor. By reviewing the published UB-MNAC and UB-MLAC, we found that to our knowledge ,it is the first time finding mesonephric remnants around the MNAC cells in the reported literature, except one case that found mesonephric remnants in the cervix, and the tumors of the three cases were all arising from the myometrium layer, without endometrium involved. Then we compared the clinical characteristics of the UB-MNAC cases arising from the myometrium and endometrium, and the results showed that the two subgroups had most in common in the clinical characteristics except the myometrium subgroup had a higher elevated CA125 level, and this result was in consistent with the Kaplan-Meier survival analysis, which indicated that the myometrium subgroup had a poorer prognosis than the endometrium group. But this need more data and further study such as the molecular analysis.<jats:bold>Conclusion Though</jats:bold> the pathogenesis of MLAC or MNAC of the uterine corpus is still under debate, according to our cases and the published literatures, We hypothesize two different pathways involved: the MNAC arising from the myometrium not affecting the endometrium may directly develop from the mesonephric remnant, the one occurred in the endometrium may not real mesonephric adenocarcinoma, but more likely arising from mesonephric transformation of Müllerian adenocarcinoma, and is better referred as MLAC. Besides, the two kinds of adenocarcinomas may have different clinical prognosis, while the MNAC arising from the myometrium may have a poorer prognosis than the MLAC originating from the endometrium, although they have identical morphologic and histologic characteristics.</jats:p>