Also called myomas, fibromyomas, and fibroids, uterine leiomyomas are the most common benign tumors in women. These smooth-muscle tumors usually occur in multiples in the uterine corpus, although they may appear on the cervix or on the round or broad ligament.

Uterine leiomyomas are often called fibroids, but this term is misleading because they consist of muscle cells and not fibrous tissue. Uterine leiomyomas occur in 20% to 25% of women of reproductive age and affect three times as many blacks as whites. The tumors become malignant (leiomyosarcoma) in less than 0.1% of patients.