Fibroid Uterus

Uterine Fibroids (Leiomyomas)

Definition

Uterine fibroids (leiomyomas) are:

• Benign, monoclonal smooth muscle tumors of the uterus that contain varying amounts of fibrous connective tissue.
• The most common pelvic tumors in women, are hormonally responsive, and may be asymptomatic or associated with symptoms such as heavy menstrual bleeding, pelvic pain, and infertility.

Pathogenesis

Step 1: Initiation of Fibroids

• Fibroids begin from one muscle cell in the uterus wall (myometrium).
• This cell undergoes a genetic change (mutation).
• The most common mutation is in the MED12 gene.
• Others include HMGA2 and some rare ones.
• Because of this mutation, that single cell starts multiplying → forming a clonal tumor (all cells come from one parent cell).

Step 2: Growth Due to Hormones

• Fibroids need hormones to grow:
  • Estrogen → increases the number of progesterone receptors in the fibroid.
  • Progesterone → the main hormone that makes the fibroid bigger, prevents cell death, and increases fibrosis (scar-like tissue).
• That’s why:
  • Fibroids grow in reproductive years (high hormones).
  • They shrink after menopause (low hormones).
  • They enlarge in pregnancy (hormones high).

Step 3: Role of Growth Factors & Extracellular Matrix (ECM)

• Fibroid cells release growth factors like TGF-β (Transforming Growth Factor), IGF, EGF.
• These growth factors:
  • Stimulate more cell division.
  • Stimulate fibroblasts to make collagen and fibronectin → this builds up ECM.
• Result: fibroids feel hard, rubbery, and fibrotic.

Step 4: Local Environment & Blood Supply

• Fibroids create their own mini environment:
• Poor blood supply → relative hypoxia (low oxygen).
• This triggers VEGF (angiogenesis factor) to form new vessels.
• Local cytokines & inflammation keep the tumor alive and expanding.

✔ In short: Fibroids start from a genetic change in one muscle cell, then hormones (estrogen & progesterone) feed the growth, while growth factors and fibrosis make them enlarge and hard. That’s why they are hormone-dependent, benign tumors.

Types of Fibroids

Classification Based on Location

• 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.

History

Demographic Data

• Name, Age (common in 30-50 years), Marital status, work.

Presenting Complaints

• Menstrual symptoms
• Heavy/prolonged bleeding
• Pressure symptoms
• Urinary frequency, urgency, retention (pressure on bladder).
• Constipation
• Abdominal lump or heaviness.
• Infertility, recurrent miscarriage, preterm labor.
• Pain
• Chronic pelvic pain
• Acute pain (red degeneration, torsion of pedunculated fibroid).

Past History

• Previous similar complaints.
• History of anemia, blood transfusions.

Obstetric & Gynecological History

• Menstrual history
• Obstetric history (number of pregnancies, outcomes).
• Contraceptive history.

Medical & Drug History

• Previous surgeries for fibroid or uterus.
• Diseases
• Medication

Family & Social History

• Family history of fibroids.
• Impact on quality of life (fatigue, social/sexual issues).
• Smoking, Alcohol

Examination

General Examination

• General appearance – pallor (anemia).
• Vital signs
• BMI/obesity.
• Signs of thyroid disease or other comorbidities.

Abdominal Examination

• Inspection – lower abdominal swelling.
• Palpation
  • Lump arising from pelvis, firm, irregular, nodular.
  • Non-tender unless degeneration present.
  • Mobile from side to side, but restricted mobility vertically.
  • Cannot be pushed below pubic symphysis (uterine origin).
• Percussion – dull over lump, resonant around.
• Auscultation – usually silent (unless pregnancy).

Pelvic Examination

• Speculum: Cervix may be pulled up, irregular, or distorted.
• Bimanual palpation:
  • Uterus enlarged, firm, irregular surface.
  • Mass continuous with uterus.
  • Mobility: mass moves with cervix.

Rectovaginal Examination

• To assess posterior fibroids and rectal involvement.

Differential Diagnosis of Uterine Leiomyoma

Related Conditions

Adenomyosis

• Definition: Benign condition where endometrial tissue is found within the myometrium.
• Risk factor: Early menarche, Nullipara
• Clinical features:
  • Dysmenorrhea
  • Abnormal bleeding
  • Infertility (difficulty conceiving and increased risk of pregnancy loss)
• Uterine findings: Irregularly enlarged, firm
• Pathology:
  • Endometrial glands and stroma within the myometrium.

Endometriosis

• Definition: Presence of endometrial tissue outside the uterus.
• Risk factor: Early menarche, Increased parity, Previous uterine surgery
• Clinical features:
  • Dysmenorrhea
  • Abnormal bleeding
  • Menorrhagia
  • Chronic pelvic pain
• Uterine findings: Typically, not enlarged
• Pathology:
  • Endometrial glands and stroma outside the uterus.

Endometrial PolypsCC?

• Definition:
  • Overgrowth of localized endometrial tissue attached to the inner wall of the uterus, usually benign
• Risk factor:
  • Menopause, Obesity, Hypertension, Tamoxifen therapy, Lynch syndrome
• Clinical features:
  • Abnormal bleeding
  • Menorrhagia
  • Postmenopausal bleeding
  • Infertility/difficulty conceive
• Uterine findings: Typically, not enlarged
• Pathology:
  • Pedunculated or sessile
  • Single or multiple
  • Length varies (up to many centimeters in size)

Uterine Leiomyosarcoma

• Definition:
  • Rare malignant tumor arising from the smooth muscle cells of the myometrium
• Risk factor: Menopause & Tamoxifen use
• Clinical features:
  • Symptoms similar to uterine fibroids
  • Menstrual irregularities
  • Postmenopausal bleeding
  • Pelvic pain
• Uterine findings: Rapidly enlarging
• Pathology:
  • Single lesions with areas of coagulative necrosis and/or hemorrhage
  • Cords of polygonal cells with eosinophilic cytoplasm, abundant mitoses, and cellular atypia are common.

Pharmacotherapy for Uterine Leiomyoma

Uterine Fibroids