Fibroids

Introduction

Fibroids, medically known as uterine leiomyomas or myomas, are benign (non-cancerous) smooth muscle tumors of the uterus. They are the most common pelvic tumors in women of reproductive age. Fibroids vary greatly in size, number, and location within the uterus, and although many are asymptomatic, some cause significant symptoms affecting quality of life.

They are hormone-dependent, primarily influenced by estrogen and progesterone, and often regress after menopause. Fibroids do not transform into malignant tumors in the vast majority of cases, but in rare instances, they may coexist with or mimic leiomyosarcomas.

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Epidemiology

• Prevalence: Affect up to 70–80% of women by age 50; clinically significant in about 20–40%.

• Age: Most common in women aged 30–50 years.

• Ethnicity: More common and often more severe in Black women compared to other ethnicities.

• Risk factors: Early menarche, nulliparity, obesity, high red meat intake, family history, vitamin D deficiency.

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Etiology and Pathophysiology

Fibroid development is linked to:

1. Hormonal Influence – Estrogen and progesterone promote fibroid growth by stimulating cell proliferation and increasing extracellular matrix production.

2. Genetic Factors – MED12 gene mutations are common in fibroid tissue.

3. Growth Factors – Increased expression of transforming growth factor-beta (TGF-β) and epidermal growth factor (EGF).

4. Extracellular Matrix Accumulation – Makes fibroids firm and rubbery.

5. Angiogenesis – Fibroids induce the formation of new blood vessels to sustain growth.

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Types of Fibroids (Based on Location)

1. Intramural fibroids – Grow within the muscular wall of the uterus; most common type.

2. Submucosal fibroids – Project into the uterine cavity; often associated with heavy menstrual bleeding and infertility.

3. Subserosal fibroids – Grow on the outside of the uterus; can become large and press on adjacent organs.

4. Pedunculated fibroids – Attached by a stalk to the uterus; can be submucosal or subserosal.

5. Cervical fibroids – Rare, develop in the cervix.

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Risk Factors

• Family history (first-degree relatives with fibroids)

• High lifetime exposure to estrogen (early menarche, late menopause)

• Obesity (higher peripheral conversion of androgens to estrogens)

• Vitamin D deficiency

• Hypertension

• Diet high in red meat, low in green vegetables

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Clinical Features

Symptoms

• Heavy or prolonged menstrual bleeding (menorrhagia)

• Pelvic pain or pressure

• Dysmenorrhea (painful periods)

• Dyspareunia (pain during intercourse)

• Abdominal distension or mass

• Frequent urination or difficulty emptying bladder (due to bladder compression)

• Constipation (due to rectal compression)

• Infertility or recurrent pregnancy loss (especially with submucosal fibroids)

• Anemia secondary to chronic blood loss

Asymptomatic Presentation

• Many fibroids are found incidentally during pelvic examination or ultrasound.

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Complications

• Severe anemia

• Urinary tract obstruction

• Hydronephrosis from ureteric compression

• Pregnancy-related complications (miscarriage, preterm labor, fetal malpresentation)

• Infertility (especially with cavity-distorting fibroids)

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Diagnosis

Physical Examination

• Enlarged, irregularly shaped, firm uterus palpable on bimanual examination.

Imaging

• Pelvic Ultrasound (transvaginal and/or transabdominal) – First-line diagnostic tool.

• Saline Infusion Sonohysterography (SIS) – Better for detecting submucosal fibroids.

• MRI – Most accurate for mapping size, number, and location; used for surgical planning.

• Hysteroscopy – Allows direct visualization of submucosal fibroids.

• Hysterosalpingography – May reveal cavity distortion.

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Management

Treatment depends on:

• Symptom severity

• Size and location of fibroids

• Patient’s age and desire for fertility

• Rate of fibroid growth

1. Expectant (Conservative) Management

• For asymptomatic or mildly symptomatic fibroids.

• Regular follow-up with pelvic exams and ultrasounds.

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2. Medical Management

Aimed at symptom control (especially heavy bleeding) and reducing fibroid size.

Hormonal Therapy

• Combined Oral Contraceptives (COCs) – Regulate menstrual cycles and reduce bleeding.

  • Examples: ethinylestradiol + levonorgestrel.

• Progestin-only therapy – Oral or intrauterine (levonorgestrel-releasing intrauterine device).

  • Examples: norethisterone, medroxyprogesterone acetate.

• Gonadotropin-Releasing Hormone (GnRH) Agonists – Induce hypoestrogenic state, reducing fibroid size.

  • Examples: leuprolide acetate, goserelin.

  • Often used preoperatively to shrink fibroids.

• GnRH Antagonists – Newer agents that rapidly reduce estrogen levels.

  • Example: elagolix.

• Selective Progesterone Receptor Modulators (SPRMs) – Reduce bleeding and fibroid size.

  • Example: ulipristal acetate (in some countries, restricted due to rare liver toxicity).

Non-Hormonal Therapy

• Tranexamic Acid – Antifibrinolytic to reduce heavy menstrual bleeding.

• NSAIDs – Reduce dysmenorrhea and menorrhagia.

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3. Minimally Invasive and Surgical Management

Uterine Artery Embolization (UAE)

• Minimally invasive radiological procedure that blocks blood flow to fibroids, causing shrinkage.

• Suitable for women not desiring future pregnancy.

MRI-Guided Focused Ultrasound Surgery (MRgFUS)

• Non-invasive, uses high-intensity ultrasound waves to ablate fibroid tissue.

Myomectomy

• Surgical removal of fibroids while preserving the uterus.

• Indicated for women desiring fertility.

• Can be performed hysteroscopically (for submucosal), laparoscopically, or via laparotomy.

Hysterectomy

• Definitive treatment for women who have completed childbearing.

• Can be total (removal of uterus and cervix) or subtotal (uterus only).

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Treatment by Symptom Profile

1. Heavy menstrual bleeding without fertility desire – LNG-IUS, tranexamic acid, COCs, UAE.

2. Fertility preservation – Myomectomy, hysteroscopic resection for submucosal fibroids.

3. Large symptomatic fibroids pre-surgery – GnRH agonists for preoperative shrinkage.

4. Refractory symptoms – Hysterectomy or UAE.

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Prognosis

• Benign course; may shrink after menopause.

• Recurrence possible after myomectomy (15–30% within 5 years).

• Symptom control is achievable in most patients with tailored treatment.