Leiomyomas are also known as fibroids.  Fibroids are muscle tumors of the uterus that are very common in the general population.  They arise from a single smooth muscle cell that has lost the proper signaling to stop growing.  Over time the muscle tumors get larger and may start to cause problems.  Women may have more that one fibroid.  Most of the fibroids are benign and cause no problems other than the problems caused by their location and size.  Large fibroids have been implicated in pelvic pain, low back pain, increased abdominal size, irregular bleeding, increased menstrual discomfort, and infertility.  Their role in infertility is not clearly understood.  There is speculation that the fibroids compress the lining of the uterus (the endometrium) or interfere with the blood supply to the endometrium.  Some fibroids are in locations that may cause blockage of the cervix or fallopian tubes.  They have also been implicated in preterm labor and early pregnancy loss.  Again, their exact mechanism of infertility is not clear and is likely different depending on the size and location of the tumor(s).

 

A view of a large fibroid uterus. The ovaries and tubes are seen on both sides. Click the image for a larger view.

The simple presence of leiomyomas does not warrant surgery in all cases. Patients with symptoms, a history of infertility, or large fibroids may benefit from surgery.  The surgical removal of fibroids is known as a myomectomy.

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There are several ways to determine if fibroids are present.  A pelvic exam is a very common way physicians evaluate the uterine size and contour.  Ultrasound also reveals abnormalities which may be suggestive of uterine leiomyomas.  Pelvic CT scanning and MRI are helpful but usually not necessary.  Many leiomyomas are discovered as patients begin their fertility evaluation.

Leiomyomas may occur in tissues outside of the uterus.  Ligaments and connective tissues in the pelvis also contain muscle fibers that may give rise to leiomyomas.   These tumors usually will not cause problems with fertility, though they are often removed for diagnostic purposes as they present as a solid mass.   Uterine leiomyomas tend to be more of a problem seen in reproductive age women and will usually regress after menopause.  Women with multiple leiomyomas are likely at higher risk for recurrence after a myomectomy.

Lupron has been used to reduce the size of fibroids and decrease abnormal bleeding associated with fibroids prior to surgery.  There is a common belief among surgeons that this therapy can make the procedure slightly more difficult and may shrink some myomas to the point they are missed at surgery.  The most common use of Lupron, therefore, is to control abnormal bleeding prior to surgery.  After discontinuation of the Lupron, the myomas resume their previous volume within several months.  There are several investigational therapies for removing myomas which include: freezing, morcellating, and embolizing.   Many physicians feel these do not offer a significant advantage to directly removing the leiomyomas and any smaller myomas that may increase a woman’s chances for a recurrence.