Uterine sarcomas are very rare. They are responsible for only 1 to 5 percent of all malignancies of the uterus
( see "Uterus: Endometrial Carcinoma" for the much more common cancer of the uterus) and account for less than 1 percent of all gynecologic malignancies ( see "Cancers of Female Pelvic Organs" ).
Uterine sarcomas are treated like other uterine cancers, but the rate of cure is not highó50 to 75 percent for early-stage disease and less than 10 percent for advanced sarcomas.
Symptoms are similar to those of endometrial carcinoma, but some women are first diagnosed as having a benign uterine tumor called a fibroid. After this rapidly growing, presumably benign fibroid is surgically removed, the pathologist finds that it is a cancerous tumor.
Types There are two general categories of tumors, pure and mixed. Those pure tumors arising from the smooth muscle of the uterine wall or from a benign fibroid are known as leiomyosarcomas and account for about 30 percent of all uterine sarcomas. Leiomyosarcomas are considered benign if there are less than 5 dividing cells on microscopic examination and malignant if there are more than 10 dividing cells. If there are between 5 to 10 dividing cells, they are considered low-grade malignancies.
