EP663 Correlation between adenomyosis and endometrial cancer: 6-year experience of a single center

Introduction/Background Adenomyosis often co-exist in the pathological reports, after surgery for endometrial cancer. The aim of this study is to describe the clinicopathological and oncological characteristics of these patients and further investigate the malignant transformation of the adenomyotic tissue. Methodology We retrospectively reviewed the medical records of all patients that underwent hysterectomy for endometrial cancer (January 2012 - December 2017) in our clinic. The pathological reports were reviewed and when adenomyosis co-existed, the pathological slides were re-examined in order to discover any malignant change in the adenomyotic tissue. The clinicopathological characteristics and oncological results were described. Results Out of 229 cases of endometrial cancer, 64 (28%) patients had concurrently endometrial cancer and adenomyosis. Among these 64 patients, 7 (11%) had malignant transformation of adenomyosis. The mean age of patients suffering from both endometrial cancer and adenomyosis was 63.2 years old and 57 (89%) of these patients, had early endometrial cancer (FIGO stage IA–IB). Out of these patients, 22 (34.4%) had grade I, 36 (56.2%) grade II and only 6 (9.4%) had grade III tumors. Moreover, in this special group of patients with concurrent endometrial cancer and adenomyosis, 25 (39%) patients presented in the pathological report fibroids and 2 (3%) endometriosis. Concerning the patients with malignant transformation of adenomyosis, their mean age was 65 years old with no premenopausal case. There was only 1 case of recurrence and none death due to cancer. Conclusion Adenomyosis, as a benign disease, is described in the last decades, but its malignant transformation is not fully researched, due to the low incidence of this entity and the relative diagnostic problems. Further investigation is needed in order to clarify the pathologic progression of adenomyotic lesions to endometrial cancer and the associated prognosis of this disease. Disclosure Nothing to disclose.