Abstract High-grade undifferentiated sarcomas (HGUSs) are rare uterine malignancies arising from the endometrial stroma. They are poorly differentiated sarcomas composed of cells that do not resemble proliferative-phase endometrial stroma. High-grade undifferentiated sarcomas are characterized by aggressive behavior and poor prognosis. Cyclin D1 has been reported as a diagnostic immunomarker for high-grade endometrial stromal sarcoma with an YWHAE-FAM22 rearrangement. YWHAE-FAM22 endometrial stromal sarcomas (ESS) represent a clinically aggressive subtype of ESS classified as high-grade endometrial sarcomas, and its distinction from the usual low-grade ESS with JAZF1 rearrangement and from HGUS with no identifiable molecular aberration may be important in guiding clinical management. Median age of the patients is between 55 and 60 years. The most common symptoms are vaginal bleeding, abdominal pain, and increasing abdominal girth.

Disease is usually advanced with approximately 70% of the patients staged III to IV according to the International Federation of Gynecology and Obstetrics classification. Preferential metastatic locations include peritoneum, lungs, intra-abdominal lymph nodes, and bone. Median progression-free survival ranged from 7 to 10 months, and median overall survival ranged from 11 to 23 months. There is no clear prognostic factor identified for HGUS, not even stage. The standard management for HGUS consists of total hysterectomy and bilateral salpingo-oophorectomy. Systematic lymphadenectomy is not recommended. Adjuvant therapies, such as chemotherapy and radiotherapy, have to be discussed in multidisciplinary staff meetings.