Fig. 1.

Schema for study design. Prior studies examined (i) endometrial cancer coexisting with adenomyosis (EC-A) compared to endometrial cancer without adenomyosis (EC w/o A), (ii) endometrial cancer arising in adenomyosis (EC-AIA) compared to endometrial cancer regardless of adenomyosis status. However, the relation between EC-AIA and EC-A is still unknown. EC-AIA defined as follows: (1) the carcinoma must not be situated in the endometrium or elsewhere in the pelvis, (2) the carcinoma must be seen to arise from the epithelium of adenomyosis and not to have invaded from another source, (3) endometrial stromal cells should be surrounding the aberrant glands to support the diagnosis of adenomyosis