Abstract
Low-grade endometrial stromal sarcoma is uncommon. The distinction between the various subgroups of uterine sarcoma cannot be made on clinical grounds alone, but requires the help of a pathologist. The sonographic patterns of uterine sarcoma have also been shown to be indistinguishable from those of benign leiomyoma. We present some uncommon sonographic findings in a case of low-grade endometrial stromal sarcoma. The blood flow characteristic of the tumor detected by color Doppler suggested its malignant potential. This unique vascular characteristic aided in the differentiation from leiomyoma with cystic degeneration.