How should I explain the meaning and management of an intramural fibroid to a patient?

How to Explain Intramural Fibroids to Your Patient

An intramural fibroid is a benign smooth muscle tumor located within the muscular wall of the uterus (the myometrium), without protruding significantly into the uterine cavity or extending to the outer surface. 1, 2

What the Patient Needs to Understand

Location and Nature

• Intramural fibroids grow inside the thick muscle wall of the uterus, distinguishing them from submucosal fibroids (which bulge into the cavity where the lining grows) and subserosal fibroids (which grow outward toward the abdominal cavity). 1, 2
• These are benign (non-cancerous) tumors composed of smooth muscle cells and connective tissue. 3
• They are extremely common—by age 50, over 70% of White women and over 80% of Black women will have fibroids, with intramural being one of the most frequent types. 3

Why This Location Matters

The intramural location has specific clinical implications that differ from other fibroid types:

• Fertility impact: Even when intramural fibroids do not distort the uterine cavity, they significantly reduce pregnancy rates (16.4% vs. 30.1% in women without fibroids) and implantation rates (6.4% vs. 15.7%) in assisted reproduction. 3, 2

• This contrasts sharply with subserosal fibroids, which do not affect fertility (pregnancy rates 34.1%), and submucosal fibroids, which have the worst impact (pregnancy rates only 10%). 3, 2

• Symptom profile: Intramural fibroids typically cause menstrual bleeding abnormalities (though less severe than submucosal types) and bulk-related symptoms including pelvic pressure, urinary frequency, and constipation. 2

What Symptoms to Expect

Explain that patients may experience:

• Heavy or prolonged menstrual bleeding leading to anemia and fatigue 3
• Pelvic pressure or fullness 3
• Urinary frequency or urgency 3
• Constipation 3
• Dysmenorrhea (painful periods) 3
• Many intramural fibroids remain asymptomatic and are discovered incidentally 3

Treatment Discussion Framework

If Fertility is Desired

Surgical myomectomy (laparoscopic or open) is the primary recommendation for symptomatic intramural fibroids when fertility preservation is important. 1, 4

• Explain that intramural fibroids negatively affect fertility even without cavity distortion, and while removing them doesn't guarantee improved fertility, myomectomy addresses symptoms and removes the mechanical barrier. 4, 5
• Important counseling point: Myomectomy carries risks of significant intraoperative blood loss and postoperative adhesion formation that may affect future fertility. 1
• For large intramural fibroids, preoperative medical therapy with ulipristal acetate or GnRH agonists can reduce fibroid size by 30-70%, potentially minimizing surgical blood loss. 1

If Fertility is Not Desired

Present options in order of definitiveness:

1. Hysterectomy provides complete resolution and is the most common treatment (75% of fibroid surgeries in the US), appropriate when symptoms are severe enough to warrant definitive treatment. 1, 6

2. Uterine artery embolization (UAE) is an effective minimally invasive alternative with equivalent symptomatic improvement to myomectomy at 2 years, though 20-32% may require subsequent surgery. 1, 4

   • Note: Intramural fibroids may be expelled after UAE in 2.2-7.7% of cases. 2, 7

3. Medical management with NSAIDs plus oral contraceptives, tranexamic acid, or GnRH agonists/antagonists can reduce bleeding symptoms but provides only temporary relief and limited volume reduction. 1, 6

Special Considerations by Size

• Small intramural fibroids (<5 cm): Medical management may be attempted first for symptom control. 5
• Large intramural fibroids (>5 cm): Medical therapy alone is unlikely to provide sufficient volume reduction for complete symptom resolution; surgical or interventional approaches are more appropriate. 1
• Very large fibroids: Larger intramural fibroids show more pronounced percentage volume reduction after UAE (positive correlation R=0.33, p=0.006). 8

Important Caveats to Discuss

• Pregnancy complications: If the patient becomes pregnant with an intramural fibroid in place, there is increased risk of spontaneous abortion, preterm delivery, abnormal fetal presentation, and postpartum hemorrhage. 3
• Red degeneration: During pregnancy or after UAE, intramural fibroids can undergo ischemic necrosis causing severe pain and fever, sometimes requiring emergency evaluation. 9
• Surveillance: If asymptomatic and treatment is deferred, transvaginal ultrasound combined with transabdominal ultrasound is the preferred monitoring modality. 6
• Racial disparities: Black women develop symptomatic disease earlier and face higher rates of surgical intervention with lower rates of minimally invasive approaches—ensure equitable access to all treatment options. 3