Endometrioid adenocarcinoma originating simultaneously from endometrium, sites of adenomyosis and ovarian endometriosis: A case report and review of our cancer database

Abstract Introduction Although adenomyosis is a common disease, it is a relatively rare site for cancer origin. On the other hand, chocolate cysts have the potential to develop into cancer. We report a case of endometrioid adenocarcinoma occurred at three sites simultaneously; uterine endometrium, adenomyosis and ovarian endometriosis. Presentation of case A 51-year-old woman underwent total hysterectomy and bilateral salpingo-oophorectomy after a diagnosis of corpus cancer (endometrioid adenocarcinoma, G1) stage IA. However, cancer was also found independently at the site of adenomyosis and in endometrioid cysts after a detailed postoperative histological investigation. There has been no sign of recurrence at 12 months after six cycles of chemotherapy with paclitaxel and carboplatin. Discussion We reviewed cases of corpus cancer between January 2011 and December 2015 from our cancer database. Two hundred thirty-three patients with corpus cancer were identified. Ovarian malignancies were found in nine cases and six cases of them were histologically the same with the corpus cancer, but ovarian endometriosis was found in only two cases. On the other hand, adenomyosis was found histologically in 30 of these cases, but the case presented here was the only one diagnosed with cancer at a site of adenomyosis. Conclusion The mechanism by which malignancy develops in the normal endometrial tissue is not clear, but if endometrial cancer is found in the uterus, it could also be present in ectopic endometrial tissues such as sites of adenomyosis or chocolate cysts.