A malignant mesenchymal neoplasm that affects the uterine corpus, and rarely, the ovaries, cervix, and vagina. In the uterine corpus it is classified as low grade or high grade endometrial stromal sarcoma. In the remainder of the anatomic sites it is classified as low grade endometrioid stromal sarcoma. The disease is MONDO_0006745 (endometrioid stromal sarcoma). Also known as: ESS, Empty Sella Syndrome, endometrial stromal sarcoma, endometrial stromal sarcoma, high grade, endometrial stromal sarcomas, ess, sarcomas, endometrial stromal, stromal sarcoma of the corpus uteri.