BackgroundUterine sarcomas are rare malignancies that resemble benign uterine leiomyomata. Uterine artery embolization is offered increasingly for treatment of uterine leiomyomata, which might lead to embolization of undiagnosed uterine sarcoma.CaseA 52-year-old woman, gravida 7, para 6, with perimenopausal menometrorrhagia was diagnosed with uterine leiomyomata after physical examination and transvaginal ultrasound. An endometrial biopsy was negative for malignancy. After medical treatment was unsuccessful, she had uterine artery embolization. She then passed a piece of tissue from her vagina, the pathology report of which was necrotic high-grade sarcoma. During surgery we confirmed that the tumor was confined to the uterus.ConclusionUterine sarcoma cannot be diagnosed except by pathologic examination of a resected specimen. Women considering uterine artery embolization for treatment of apparent leiomyomata should be counseled on the risk of decreased survival by delaying diagnosis and treatment of uterine sarcoma.