What Is a Uterine Cyst?

A uterine cyst, also called a uterine fibroid, myoma, or fibromyoma, is a growth in the uterus. These growths are very common and up to 75 percent of women at some point during their child-bearing years. Uterine cysts are usually not cancerous or cause for major concern, though they can cause pelvic pain, fertility problems, heavy or prolonged menstrual bleeding, and bladder problems. The cysts often require no treatment unless symptoms are severe, and many women are unaware they have a cyst until it shows up on an ultrasound or during a pelvic examination.

Uterine cysts that grow inside the uterus are known as submucosal fibroids. This type of cyst may cause heavy bleeding during the menstrual period and may make it difficult for women to get pregnant. Subserosal fibroids are cysts that develop outside the uterus. These cysts can press on the bladder or rectum, causing urinary incontinence or constipation. Subserosal fibroids occasionally cause back pain if they grow on the back of the uterus and press on the nerves surrounding the spinal cord.

The precise cause of cysts in the uterus is unknown, but genetic abnormalities, hormonal fluctuations, and a familial history of cysts can contribute to the condition. Women who experience menstrual problems, including abnormally heavy bleeding or bleeding for more than seven days, should see a doctor to determine if they have a uterine cyst. Severe pelvic pain, bowel, and bladder problems with no other apparent cause should also be evaluated.

Doctors diagnose these cysts with various imaging studies. The most common way to diagnose these fibroids is through an ultrasound, which allows the doctor to see an image of the uterus and identify any abnormal masses. In some cases, doctors insert a small, lighted instrument through the vaginal cavity and cervix to examine the uterus in a procedure called a hysteroscopy. This allows the physician to examine the openings of the fallopian tubes, which is helpful if a woman with a uterine cyst is having difficulties getting pregnant.

Most cysts in the uterus are not cancerous and may not require treatment. For patients whose symptoms do not improve, doctors often prescribe medications to shrink the fibroids and improve symptoms. These medications include androgens and nonsteroidal anti-inflammatory drugs. Intrauterine devices and hormonal contraceptives help control menstrual-related symptoms, though they do not shrink the actual cysts.

In severe cases where a cyst causes symptoms that cannot be controlled with medications, doctors may elect to remove the fibroid through a surgical procedure. Most of these procedures are minimally invasive and use a laparoscope, a small instrument with a camera and light on the end, to help the surgeon navigate around the cyst to cut it away, freeze it with liquid nitrogen, use an electric current to destroy fibroids inside the uterus, or inject chemicals or particles into the cyst to cut off the blood flow and force them to shrink. The only permanent solution for uterine cysts is a hysterectomy, which completely removes the uterus. This option is usually a last resort because it prevents the woman from having children and may initiate menopause if the ovaries are also removed.