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