Uterine fibroids, also known as uterine leiomyomas or fibroids, are benign smooth muscle tumors of the uterus. Most women have no symptoms while others may have painful or heavy periods. If large enough, they may push on the bladder causing a frequent need to urinate. They may also cause pain during sex or lower back pain. A woman can have one uterine fibroid or many of them. Occasionally, fibroids may make it difficult to get pregnant, although this is uncommon.
Fibroids, particularly when small, may be entirely asymptomatic. Symptoms depend on the location and size of the fibroid. Important symptoms include abnormal uterine bleeding, heavy or painful periods, abdominal discomfort or bloating, painful defecation, back ache, urinary frequency or retention, and in some cases, infertility.There may also be pain during intercourse, depending on the location of the fibroid. During pregnancy, they may also be the cause of miscarriage,bleeding, premature labor, or interference with the position of the fetus.
While fibroids are common, they are not a typical cause for infertility, accounting for about 3% of reasons why a woman may not be able to have a child. The majority of women with uterine fibroids will have normal pregnancy outcomes. In cases of intercurrent uterine fibroids in infertility, a fibroid is typically located in a submucosal position and it is thought that this location may interfere with the function of the lining and the ability of the embryo to implant.Also, larger fibroids may distort or block the fallopian tubes.
While palpation used in a pelvic examination can typically identify the presence of larger fibroids, gynecologic ultrasonography (ultrasound) has evolved as the standard tool to evaluate the uterus for fibroids. Sonography will depict the fibroids as focal masses with a heterogeneous texture, which usually cause shadowing of the ultrasound beam. The location can be determined and dimensions of the lesion measured. Also magnetic resonance imaging (MRI) can be used to define the depiction of the size and location of the fibroids within the uterus.
Imaging modalities cannot clearly distinguish between the benign uterine leiomyoma and the malignant uterine leiomyosarcoma, however, the latter is quite rare. Fast growth or unexpected growth, such as enlargement of a lesion after menopause, raise the level of suspicion that the lesion might be a sarcoma. Also, with advanced malignant lesions there may be evidence of local invasion. Biopsy is rarely performed and if performed, is rarely diagnostic. Should there be an uncertain diagnosis after ultrasounds and MRI imaging, surgery is generally indicated.Other imaging techniques that may be helpful specifically in the evaluation of lesions that affect the uterine cavity are hysterosalpingography or sonohysterography.