The risk of sarcoma developing in a fibroid uterus is approximately

Though uterine sarcoma is rare--with the annual incidence of leiomyosarcomas at approximately 0.4 to 0.64 per 100,000 women--it has been estimated that approximately 1:8300 to 1:352 women undergoinguterine surgery for presumedfibroids have unsuspected sarcoma.