stromal sarcoma survivalmetastatic endometrial stromal sarcomaendometrial stromal sarcoma pathologyendometrial stromal sarcoma cancerendometrial stromal sarcoma stage 4endometrial stromal cell sarcomaendometrial sarcomaendometrial stromalstromal sarcoma uterusundifferentiated endometrial sarcomametastatic endometrial sarcomaendometrial stromal tumor