ambossIconambossIcon

Uterine leiomyoma

Last updated: February 6, 2025

Summarytoggle arrow icon

Uterine leiomyomas (also known as fibroids) are benign, hormone-sensitive uterine neoplasms. They are classified as either submucosal (beneath the endometrium), intramural (within the muscular uterine wall of the uterus), or subserosal (beneath the peritoneum) and can occur within the uterine corpus or the cervix. Symptoms depend on the location, size, and number of leiomyomas, and include menstrual abnormalities (e.g., menorrhagia), mass effect (e.g., back, abdominal, and/or pelvic pain; bladder and/or bowel dysfunction), and infertility. Ultrasound is typically used to establish the diagnosis. Treatment is selected using shared decision-making, taking into consideration the patient's desire for fertility and/or uterine preservation, menopausal status, and symptom severity. Asymptomatic patients can often be managed expectantly. Treatment for symptomatic patients may include surgery (myomectomy or hysterectomy), nonsurgical interventional treatments (e.g., uterine artery embolization), and/or pharmacotherapy, including gonadotropin-releasing hormone (GnRH) agonists, GnRH antagonists, intrauterine devices (IUDs), and/or oral contraceptives.

Icon of a lock

Register or log in , in order to read the full article.

Overviewtoggle arrow icon

Icon of a lock

Register or log in , in order to read the full article.

Etiologytoggle arrow icon

Predisposing factors [1][2]

Icon of a lock

Register or log in , in order to read the full article.

Classificationtoggle arrow icon

Leiomyomas are classified according to their location. [3]

  • Subserosal leiomyoma: located in the outer uterine wall beneath the peritoneal surface
  • Intramural leiomyoma (most common): growing from within the myometrium wall
  • Submucosal leiomyoma: located directly below the endometrial layer (uterine mucosa)
  • Cervical leiomyoma: located in the cervix
  • Diffuse uterine leiomyomatosis: The uterus is grossly enlarged due to the presence of numerous fibroids.

-

Icon of a lock

Register or log in , in order to read the full article.

Clinical featurestoggle arrow icon

Symptoms depend on the number, size, and location of leiomyomas. Most women have small, asymptomatic fibroids.

Icon of a lock

Register or log in , in order to read the full article.

Diagnosistoggle arrow icon

General principles [4][5]

Uterine leiomyomas are extremely common (affecting 70% of women) and are often found incidentally on ultrasound; do not attribute abnormal uterine bleeding to leiomyomas until other etiologies have been ruled out! [4][6]

Imaging [5][7]

Ultrasound pelvis (transvaginal, transabdominal)

  • Most appropriate initial test for all patients with a suspected uterine leiomyoma [7]
  • Supportive findings [8]

Neither plain radiography nor CT is recommended in the workup of leiomyomas because of poor visualization (unless calcified). [7][9]

Further imaging [7][10]

Although imaging cannot definitively distinguish between a leiomyoma and a leiomyosarcoma, hypervascularity within a solitary heterogeneous uterine mass should raise suspicion for a leiomyosarcoma. [8]

Laboratory studies [4][5][11]

Advanced studies

Not routinely performed; consider in case of diagnostic uncertainty

Consult a gynecologic oncologist early to help guide further diagnostic studies if leiomyosarcoma is suspected (e.g., in patients with continued leiomyoma growth after menopause).

Icon of a lock

Register or log in , in order to read the full article.

Pathologytoggle arrow icon

  • Macroscopic
    • 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

References:[13]

Icon of a lock

Register or log in , in order to read the full article.

Treatmenttoggle arrow icon

Overview [4][14]

Management should be based on shared decision-making and tailored to the patient's symptoms and desire for fertility and/or uterine preservation.

Leiomyomas tend to regress after menopause; expectant management or pharmacotherapy as a bridge to menopause is recommended for most perimenopausal patients. [4]

Racial disparity exists in the treatment of leiomyomas: Typically, Black patients are less likely to be offered nonsurgical or minimally invasive therapies than White patients, even after adjusting for clinical features such as leiomyoma size. [4]

Expectant management [4]

Indications

  • Asymptomatic or minimally symptomatic patients
  • Perimenopausal patients

Management

  • Monitor reported symptoms for any worsening at annual well-woman exams.
  • Typically, no active treatment is required.
  • Surveillance imaging is not routinely required. [14]
  • Recommend follow-up if symptoms change or pregnancy is planned.

Pharmacotherapy [4]

  • Medications can either be used long-term for symptom control or temporarily as a bridge until a more definitive modality can be performed.
  • Pharmacotherapy should be selected based on the patient's symptoms.
  • There is currently insufficient evidence to recommend one agent over other for first-line therapy.
Pharmacotherapy for uterine leiomyoma [4]
Predominant symptoms Agents Important considerations
Heavy menstrual bleeding without features of mass effect
Mass effect with or without heavy menstrual bleeding

Selective progesterone receptor modulators (e.g., ulipristal acetate) and androgenic agonists (e.g., danazol) are used in some countries for the management of leiomyomas; these medication classes are not FDA-approved for managing leiomyomas in the US, as the potential adverse effects are thought to outweigh the benefits.

GnRH antagonists have a faster clinical effect than GnRH agonists, as there is no initial increase in FSH/LH and estrogen with GnRH antagonists.

Nonsurgical interventional treatments [4][17]

Recommended in patients with symptomatic leiomyoma who desire uterine preservation and/or want to avoid surgery.

Uterine artery embolization (UAE)

Radiofrequency ablation (RFA) [4][17]

Additional modalities (not currently recommended)

Nonsurgical interventional therapies preserve the uterus; however, there is insufficient data regarding their effect on fertility to support their use in women who may wish to conceive in the future.

Surgery [4]

Myomectomy

A uterus-preserving surgical option for the removal of leiomyomas

Hysterectomy

  • Indications
    • Patients seeking definitive treatment who do not desire fertility and/or have had an insufficient response to alternative treatments
    • Suspected leiomyosarcoma [20]
  • Approach : vaginal, abdominal, or laparoscopic

Patients often receive GnRH agonists or antagonists prior to surgery to reduce leiomyoma size, which may allow less invasive procedures to be performed. [4]

Icon of a lock

Register or log in , in order to read the full article.

Differential diagnosestoggle arrow icon

Differential diagnosis of uterine leiomyoma
Factors Uterine leiomyoma (fibroids) Adenomyosis Endometriosis Endometrial polyps Uterine leiomyosarcoma [21][22]
Definition
  • Overgrowth of localized endometrial tissue attached to the inner wall of the uterus, usually benign [23]
Risk factors
Clinical features
Uterine findings
  • Irregularly enlarged, firm
  • Uniformly enlarged
  • Typically not enlarged
  • Typically not enlarged
  • Rapidly enlarging
Pathology

The differential diagnoses listed here are not exhaustive.

Icon of a lock

Register or log in , in order to read the full article.

Complicationstoggle arrow icon

We list the most important complications. The selection is not exhaustive.

Icon of a lock

Register or log in , in order to read the full article.

Special patient groupstoggle arrow icon

Uterine leiomyomas during pregnancy [26]

Effects of leiomyomas in pregnancy [26][27]
Common complications
Antenatal period
Peripartum period
Postpartum period

After pregnancy, leiomyomas typically return to their prepartum size; however, some leiomyomas may spontaneously resolve. [28]

Icon of a lock

Register or log in , in order to read the full article.

Start your trial, and get 5 days of unlimited access to over 1,100 medical articles and 5,000 USMLE and NBME exam-style questions.
disclaimer Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer