Uterine fibroids are benign tumors that originate in the uterus (womb). Although they are composed of the same smooth muscle fibers as the uterine wall (myometrium), they are much denser than normal myometrium. Uterine fibroids are usually round. Uterine fibroids are often described based upon their location within the uterus. Fibroids are located along the lining of the uterus.
Early pregnancy decreases the likelihood that fibroids will develop. Fibroids have not been observed in girls who have not reached puberty, but adolescent girls may rarely develop fibroids. An increased risk of developing fibroids include having the first menstrual period (menarche) prior to age 10, consumption of alcohol, uterine infections and elevated blood pressure.
Uterine fibroids are diagnosed by pelvic exam and even more commonly by ultrasound. Often, a pelvic mass cannot be determined to be a fibroid on pelvic exam alone, and ultrasound is very helpful in differentiating it from other conditions such as ovarian tumors. MRI and CT scans can also play a role in diagnosing fibroids, but ultrasound is the simplest, cheapest, and best technique for imaging the pelvis. Occasionally, when trying to determine if a fibroid is present in the uterine cavity (endometrial cavity), a hysterosonogram (HSG) is done. In this procedure, an ultrasound exam is done while contrast fluid is injected into the uterus through the cervix.
Non-surgical techniques are usually hormonal in nature and include the use of drugs that turn off the production of estrogen from the ovaries. These medications are given for three to six months. When successful, they can shrink the fibroids by as much as 50%.
Side effects of these drugs are similar to the symptoms of menopause and can include hot flashes, sleep disturbance, vaginal dryness, and mood changes. Bone loss leading to osteoporosis after long-term (6 to 12+ months) use is one complication.