Question: are uterine fibroid tumors cancerous?
Answer: Fibroids are almost always benign (not cancerous). Rarely (less than one in 1,000) a cancerous fibroid will occur. This is called leiomyosarcoma. (leye-oh-meye-oh-sar-KOH-muh) Doctors think that these cancers do not arise from an already-existing fibroid.