metastatic endometrial stromal sarcomaendometrial stromal sarcoma pathologyendometrial stromal sarcoma stage 4endometrial stromal cell sarcomaendometrial sarcomaendometrial stromalsarcoma uterine cancerendometrial carcinoma sarcomastromal sarcoma uterusundifferentiated endometrial sarcomametastatic endometrial sarcomaendometrial stromal tumor