Myometrium: Uterine Fibroids
A fibroid is a benign tumour of uterine smooth muscle, a
• Gross appearance:
Firm, whorled tumour located adjacent to & bulging into
the endometrial cavity (submucous fibroid)
Centrally within the myometrium ( Intramural fibroids)
Attached to uterus by narrow pedicle (Pedunculated
• Fibroids can arise separately from the uterus esp.
from broad lig presumably embryonal remnants
• Appearance may be altered and 3 form are;
1. Red degeneration is due to acute disruption of
May present with acute onset of pain and tenderness over
assoc with mild pyrexia & leukocytosis.
2. Hyaline degeneration;
When fibroids outgrow its blood supply
• Key feature is occurrence in reproductive yrs.
• Racial or familial predisposition.
• Possibility of abnormal ER has been explored
• Both main Progesterone Receptor subtypes are expressed
in myoma & normal myometrium
• Exp’t Progesterone has been shown to stimulate
production of apoptosis-inhibiting protein and EGF.
• Oestradiol has the effect of stimulating expression
• Reduced expression of Inhibitory factors eg MCP-1
may contribute to loss of inhibitory required for
• Tx by Ovarian suppression is assoc with increase in
MMP and decease in TIMP activity
• Cytogenic studies: Indiv Myoma are monoclonal in
origin but ell from diff myomas within the uterus
are independent in origin
• Clonal expansion of tumour cell precede dev’t of
• Common cytogenic aberations are detected in
chromosomes 12, 6, 7 , aring chrom 1 &
translocation involving 12 & 14.
• Relevant areas on chrom 12, 6 & 7 contain putative
GR & TSG.
• Risk of malignant transformation 0.5%
• In leimyosarcoma, tissue are of more extensive
• With frequent deletions especially involving
chromosomes 1 & 10
• Common & detectable in 20% of women over 30yrs
• Autopsy shows prevalence of up to 50%.
• Risk factors
A family history
African racial origin
• Majority don’t cause symptoms & identified
Pressure symptoms esp. urinary frequency.
Pain is unusual except in acute degeneration
Menorrhagia may occur coincidentally
• Subfertility may result from mechanical distortion
or occlusion of Fallopian tube
• Prevention of implantation esp by submucous
• Risk of miscarriage is not increased once pregnancy
• In late pregnancy may be the cause of abnormal lie.
• Postpartum hemorrhage may occur due to
inefficient uterine contraction.
• Abdominal examination may indicate presence of a
firm mass arising from pelvis
• Bimanual exams; the mass is felt to be part of the
uterus usually with some mobility
• Other causes of abdominopelvic mass should be
• Uterus with fibroids is firm in contrast to that
enlarged with pregnancy.
• An ovarian tumour
• Leimyosarcoma typically resent with rapidly
enlarging abdominopelvic mass.
Less mobility of uterus than expetedin fibroid and general
signs of cachexia
1. Clinical features alone is usually sufficient
2. Hb conc to help indicate anaemia if there is
clinically significant menorrhagia.
3. Ultrasonography is is useful in distinguishing a
uterine from an ovarian mass.
4. Imaging of Urinary tract to exclude
5. Clinical suspicion of sarcoma: do needle biopsy
or urgent laparotomy
Hysteroscopic appearance of fibroid polyp within the
Conservative management is appropriate
Ovarian suppression using GnRH agonist
Mifepristone has been shown to be effective in shrinking
Choice of tx is by patients PC and aspiration for normal
menstruation and fertility.
Pretreatment with GnRH for 2 months facilitates the process.
a) Pelvic examination often reveals an enlarged &
b) If the woman has no symptoms and the uterus is
not enlarged, no tx is indicated.
c) If the woman is symptomatic, hysterectomy is the
preferred tx, since adenomyosis does not respond
well to hormonal treatment.