Uterine leiomyomas (fibroids) are benign, hormone-sensitive uterine neoplasms. These tumors are classified as either submucosal (beneath the endometrium), intramural (within the muscular uterine wall of the uterus), or subserosal (beneath the peritoneum). Symptoms depend on the location, size, and number of myomas, and include menstrual abnormalities (menorrhagia), features of mass effects (e.g., back/abdominal/pelvic pain or bladder and bowel dysfunction), and infertility. Physical examination and sonohysterography are used to establish the diagnosis. Treatment for symptomatic patients includes surgery (myomectomy or hysterectomy) as well as interventional (uterine artery embolization) and/or medical therapy (GnRH agonists).
- A benign, hormone-sensitive smooth muscle tumor of the uterus
- Can be submucosal, intramural, or subserosal
- Arises from a single myometrial cell (monoclonal growth) and causes:
- Results in an overgrowth of smooth muscle cells and connective tissue (often multiple tumors)
- The myometrium also develops vascular changes (e.g., increased arterioles and venules, dilated veins).
- The most common tumor of the female genital tract.
- Early menarche (< 10 years old)
- Age: 25–45 years
- Increased incidence in African American individuals
- Family history
Leiomyomas are classified according to their location within the uterus:
- Subserosal leiomyoma: localized in the outer uterine wall beneath the peritoneal surface
- Intramural leiomyoma (most common): growing from within the myometrium wall
- Submucosal leiomyoma: localized directly below the endometrial layer (uterine mucosa)
- Diffuse uterine leiomyomatosis: The uterus is grossly enlarged due to the presence of numerous fibroids.
Most women have small, asymptomatic fibroids. Symptoms depend on the number, size, and location of leiomyomas.
- Abnormal menstruation
- Features of mass effect
- Reproductive abnormalities
- Ultrasound (best initial test)
- Hysteroscopy: to assess submucosal fibroids
- MRI: to evaluate the uterus and ovaries for potentially complicated surgical cases and visually differentiate between leiomyomas, adenomyomas, and adenomyosis
- Grayish-white surface
- Homogeneous; tissue bundles on cross-section partly in a whorled pattern
- Some leiomyomas may involve regressive changes: scar formation, calcification, and cysts
- Microscopic: Smooth muscle tissue in a whorled pattern with well-demarcated borders, consisting of monoclonal cells interspersed with connective tissue
- Uterine fibroids, adenomyosis, and endometriosis may be present simultaneously in the same patient.
- See also , , and
|Differential diagnosis of uterine leiomyoma|
|Factors||Uterine leiomyoma (fibroids)||Uterine polyps||Uterine leiomyosarcoma |
|Risk factors|| |
|Uterine findings|| || || || || |
|Pathology|| || || |
The differential diagnoses listed here are not exhaustive.
Treatment should only be considered in symptomatic patients because of the side effects of medical therapy and surgery. The goal is to relieve symptoms. Perimenopausal women warrant expectant management in most cases.
- Do not require treatment
- Frequent follow-ups (approx. every 6–12 months) with pelvic ultrasonography; and symptom monitoring
- Patients should be counseled to contact their physician if new symptoms develop.
Gonadotropin-releasing hormone (GnRH) agonists: e.g., leuprolide, goserelin, nafarelin
- Optimal treatment prior to surgery; but not suited for long-term monotherapy (> 6 months) because they cause osteoporosis, hot flushes, depression
- Decrease size of leiomyomas
- Suppress growth of new leiomyomas
- Decrease tumor vascularization
- Induce amenorrhea and thereby improve anemia
- Leiomyomas grow back once therapy is discontinued (rebound growth)
- Progestin-releasing (IUD): controls heavy and painful bleeding but does not treat fibroids themselves (only for fibroids that do not distort the inside of the uterus)
- Selective progesterone receptor modulator: ulipristal
- Gonadotropin-releasing hormone (GnRH) agonists: e.g., leuprolide, goserelin, nafarelin
- Antifibrinolytics (e.g., tranexamic acid): reduce heavy bleeding
- Androgenic agonists (e.g., danazol): suppress growth of fibroids but have many side effects (e.g., acne, edema, hair loss, etc.)
- NSAIDs: : for dysmenorrhea
Uterine fibroid embolization: uterine artery embolization
- Procedure: injection of polyvinyl alcohol (PVA) into the arteries that supply blood to the fibroid, causing it to shrink; ¼ of patients may require further invasive treatment
- Continued heavy bleeding and/or severe pain with insufficient response to medical treatment
- Contraindications to surgery or personal preference to avoid surgery
- No wish to conceive in the future
- Indications: rapidly growing fibroid, recurrent refractory bleeding: secondary to medical therapy, severe symptoms
- Iron deficiency anemia (due to heavy menstrual bleeding)
- Fibroid torsion
- Very rare: malignant transformation to uterine leiomyosarcoma
We list the most important complications. The selection is not exhaustive.
Special patient groups
Uterine leiomyomas during pregnancy
- Elevated concentrations of progestin and estrogen foster the growth of leiomyomas.
- Pain may be caused by:
- Premature contractions
- Depending on location and size:
- Cervical leiomyoma: obstruction of the birth canal is an indication for cesarean delivery
- Postpartum: atonic hemorrhages
- Puerperium: fibroid regression accompanied by calcification