Uterine fibroids

Uterine fibroids (leiomyomata, singular leiomyoma) are the most common neoplasm in females, and may affect about of 25 % of white and 50% of black women during the reproductive years. They are a major indication for a hysterectomy.

Pathology and histology

Leiomyomas grossly appear as round, well circumscribed (but not encapsulated), solid nodules that are white, or tan whorled. The size varies, from microscopic to lesions of considerable size. Typically lesions the size of a grapefruit or bigger are felt by the patient herself through the abdominal wall. Microscopically, tumor cells resemble normal cells (elongated, spindle-shaped, with a cigar-shaped nucleus) and form bundles with different directions (whirled). These cells are uniform in size and shape, with scarce mitoses. There are three benign variants: bizarre (atypical); cellular; and mitotically active.

Estrogen dependence

Leiomyomas are estrogen sensitive and have estrogen receptors. They may enlarge rapidly during pregnancy presumably due to increased estrogen levels. As estrogen levels decline with menopause, fibroids tend to regress after menopause. Hormonal therapy takes advantage of the fact that lack of estrogens leads to shrinkage of fibroids.

Symptoms

Fibroids, particularly when small, may be entirely asymptomatic. Generally, symptoms relate to the location of the lesion and its size. Important symptoms include abnormal gynecological hemorrhage , pain, infertility, dysuria and urinary frequency. During pregnancy they may be the cause of abortion, bleeding, premature labor, or interference with the position of the fetus.

Location

Fibroids may be single or multiple. Most fibroids start in an intramural location,- that is the layer of the muscle of the uterus. With further growth, some lesion may develop towards the outside of the uterus (subserosal or pedunculated), some towards the cavity (submucosal or intracavitary). Lesions affecting the cavity tend to bleed more and interfere with pregnancy. Secondary hanges that may be develop within fibroids are hemorrhage, necrosis, calcification, and cystic changes. Less frequently, leiomyomas may occur at the lower uterine segment, [[cervix], or uterine ligaments .

Diagnosis

Diagnosis is usually accomplished by bimanual examination, better yet by gynecologic ultrasonography. Sonography will depict the fibroids as focal masses with a heterogeneous texture, which usually cause shadowing of the ultrasound beam. In cases where a more precise assay of the fibroid burden of the uterus is needed, also magnetic resonance imaging (MRI) can be used to generate a depiction of the size and location of the fibroids within the uterus. While no imaging modality can clearly distinguish between the benign uterine leiomyoma and the malignant uterine leiomyosarcoma, the rarity of the latter and the prevalence of the former make it, for practical purposes, a non-issue unless evidence of local invasion is present. For this reason, biopsy is rarely performed.

Treatment

The presence of a fibroid does not mean that it needs to be treated, many lesions are followed expectantly. Treatment of uterine fibroids that cause problems can be accomplished by:

1. Surgery: Hysterectomy or myomectomy can be performed. Based on the size and location of the lesion different approaches can be considered: laparotomy, laparoscopy, or hysteroscopy.
2. Uterine artery embolisation (UAE): Using interventional radiology, the physician occludes both uterine arteies and thus interferes with the blood support of the fibroid(s).
3. Medical therapy: This involves the use of medication to reduce estrogens in an attempt to create a medical menopause-like situation. Gonadotropin-releasing hormone analogs are used for this.
4. HIFUS: High frequency focused ultrasound sonography is a targetted application of external sonographic waves to destroy fiboid lesions

Malignancy

Very few lesions are maligant. Signs that a fibroid may be malignat are rapid growth or growth after menopause. Such lesions are typically a leiomyosarcoma.

See also

• leiomyoma