The uterus is made up of muscle cells. In fact, it is one big muscle. This muscular construction allows the uterus to relax and expand to accommodate a baby as well as to contract back down to size after delivery.
Fibroids, or leiomyomas (myomas for short), occur when one of these smooth muscle cells divides more rapidly than those around it. As a result, a lump (or tumor) that is distinct from the surrounding cells develops.
Symptoms of Uterine Fibroids
It is estimated that nearly three out of four women will eventually develop one or more fibroids in their lifetime, although most of them will go unrecognized because they do not produce any symptoms.
Other fibroids, because of their size or because of their location, can produce symptoms including irregular or heavy bleeding, pain with periods or with intercourse, or problems with conceiving or carrying a pregnancy.
Fibroids that are located in the outer part of the uterine wall (subserosal) generally do not produce symptoms unless they become large enough to take up so much space that they put pressure on surrounding organs or tissues. Fibroids that are located close to the inner cavity of the uterus (submucosal) frequently cause irregular or heavy bleeding and cramping. These often protrude into the uterine cavity and may interfere with pregnancy, causing difficulties conceiving or even miscarriages. Those fibroids located within the uterine wall itself can cause pain or heavier periods, but unless they actually distort the uterine cavity or become quite large, they are generally thought to have little effect on the ability of the uterus to carry a pregnancy.
While it is possible for a fibroid to be malignant, this is rare. Only three to seven women out of every 100,000 will be diagnosed with a malignant fibroid.
Fibroids that are large enough to cause symptoms or are located in a position that may affect the ability to carry a pregnancy should be treated. Most fibroids are treated with surgical removal, which allows them to be examined for malignant potential. The uterus is a resilient organ and, in most cases, is able to successfully carry a pregnancy even after the removal of multiple fibroids.
Another option for treatment is embolization. With this treatment, the blood vessels that supply the fibroid are plugged with small particles that cause the fibroid to shrink and die from lack of blood supply. While this avoids major incisions, it still usually requires hospitalization for pain control. Additionally, there are concerns that some of the particles may travel to the ovaries and negatively affect their function in women still wanting pregnancy. Fortunately, surgery for fibroids is increasingly being performed via minimally invasive techniques such as hysteroscopy or robotic surgery.
Which method of treatment is best for you will depend upon the size, number and location of the fibroids and whether or not a future pregnancy is desired. Your doctor will determine the correct course during your initial consultations.