Rapid growth of a fibroid is not a predictor of leiomyosarcoma. In women undergoing surgery for fibroids approximately 1 in 400 (0.25%) is at risk of having a leiomyosarcoma. However, growth and/or new onset of symptoms post-menopause should carry a higher index of suspicion for malignancy. Incidental uterine leiomyosarcomas have been encountered during routine resectoscopic myomectomy, though their incidence appears to be lower than that reported following hysterectomy (0.13%). Leiomyomas and leiomyosarcomas cannot reliably be distinguished clinically or by any imaging technique.
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