What Are Uterine Fibroids (Leiomyomas)?
Uterine fibroids, clinically known as leiomyomas or myomas, are benign (non-cancerous) monoclonal tumors originating from the smooth muscle cells (myometrium) of the uterine wall. Fibroids are exceptionally common, occurring in up to 70% to 80% of women by age 50, though many remain small, asymptomatic, and require no treatment.
Fibroid growth is hormonally responsive, stimulated by circulating estrogen and progesterone. Consequently, fibroids typically enlarge during reproductive years and regress after menopause when systemic hormone levels decline.
3 Anatomical Types of Fibroids
1. Submucosal Fibroids
Grow beneath the inner uterine lining (endometrium) and bulge into the uterine cavity. Even small submucosal fibroids can cause severe heavy menstrual bleeding (menorrhagia) and interfere with embryo implantation.
2. Intramural Fibroids
Develop entirely within the muscular myometrial wall. As they expand, they distort the uterine contour, causing heavy periods, painful cramps, and diffuse pelvic pressure.
3. Subserosal Fibroids
Project outward from the outer serosal surface of the uterus. They rarely cause heavy bleeding but can press against adjacent organs, causing urinary frequency or constipation.
Common Symptoms: Heavy Bleeding & Bulk Pressure
- Heavy or Prolonged Menstrual Bleeding: Soaking through pads or tampons rapidly, passing blood clots, or periods lasting longer than 7 days.
- Pelvic Bulk & Pressure: A feeling of heaviness or fullness in the lower abdomen, similar to early pregnancy.
- Urinary & Bowel Compression: Frequent urination, difficulty emptying the bladder, or constipation due to subserosal mass effect.
- Pelvic Pain & Dyspareunia: Deep pelvic aching, painful cramps during menstruation (dysmenorrhea), or discomfort during sexual intercourse.
Fibroids vs. Adenomyosis vs. Endometriosis
| Condition | Pathophysiology Location | Key Distinguishing Symptom | Primary Diagnostic Tool |
|---|---|---|---|
| Uterine Fibroids | Focal myometrial smooth muscle tumors | Heavy bleeding & pelvic bulk pressure | Transvaginal Ultrasound (TVUS) / MRI |
| Adenomyosis | Diffuse endometrial glands inside myometrium | Globular "boggy" uterus & severe cramps | High-resolution TVUS / Pelvic MRI |
| Endometriosis | Ectopic endometrial tissue outside uterus | Severe chronic pelvic pain & dyspareunia | Laparoscopy / Expert TVUS |
Evidence-Based Medical & Surgical Management
Treatment for fibroids is highly individualized based on symptom severity, fibroid location, age, and future pregnancy plans:
1. Watchful Waiting
Asymptomatic or small fibroids generally require no treatment, only routine clinical monitoring.
2. Medical & Hormonal Therapy
Levonorgestrel IUD (LNG-IUD), tranexamic acid, NSAIDs, or GnRH receptor antagonists can significantly reduce heavy bleeding.
3. Minimally Invasive & Surgical Options
Myomectomy (surgical removal of fibroids preserving uterus), Uterine Artery Embolization (UAE / blocking blood supply), or Hysterectomy for definitive management when fertility is complete.