Mesonephric adenocarcinoma arising from the uterine corpus: case reports and literature review

Background: Mesonephric adenocarcinoma (MNAC) is a rare carcinoma arising from the mesonephric remnant of the gynecologic tract. It mainly occurs in the uterine cervix, barely locating in the uterine corpus, ovarian and vagina. The histogenesis of MNAC arising from of the uterine body (UB-MNAC) is not yet clear. They may originate in M & uuml;llerian tissue and exhibit the mesonephric differentiation phenotype, or arise from the mesonephric remnants in the uterine wall. We presented three cases diagnosed as UB-MNAC from the West China Second University Hospital. To our knowledge, it is the first time finding mesonephric remnants around the MNAC cells in the reported literature, and the tumors of the three cases were all arising from the myometrium layer, without endometrium involved. Case Description: Notably, two of the three cases found mesonephric remnants around the tumor, and interestingly, the two tumors were all arising from the myometrium layer of the uterine corpus. The three patients all received standard surgery and systematic chemotherapy after surgery, showing no signs of recurrence by now. Then, we reviewed the published MNAC and Mesonephric-like adenocarcinoma (MLAC) arising from the uterine corpus, and found that except one case finding mesonephric remnants in the cervix. Besides, we found the myometrium subgroup had a higher elevated CA125 and poorer prognosis than the endometrium group. Conclusions: Though the pathogenesis of MLAC or UB-MNAC is still under debate, we hypothesize two different pathways involved: the MNAC arising from the myometrium not affecting the endometrium may directly develop from the mesonephric remnant, but the one occurred in the endometrium may more likely arise from mesonephric transformation of M & uuml;llerian adenocarcinoma, and is better referred as MLAC. Besides, the two kinds of adenocarcinomas may have different clinical prognosis, while the myometrium subgroup may have a poorer prognosis than the endometrium subgroup. And better understanding of the histogenesis for the UB-MNAC and MLAC could fascinate the treatment and rehabilitation.