Uterine Fibroids
Definition :It is a benign tumor of the smooth muscle fibers of the uterus .
Fibroid is the commonest term but leiomyoma is the most correct term .
Incidence :
It is the commonest uterine tumor and the most common solid pelvic tumor in women . It occurs in 20-25% of all reproductive age females .It is diagnosed mostly in patients about 30 40 years .
Occurs more in nulliparas or cases of low parity .
In negros , myomas are 3-9 times more , appear at earlier age , and grow faster than white races .
Etiology :
Relative estrogen excess ( mediated through growth factors ) . No new tumors develop after menopause and existing tumors tend to atrophy .Smoking decrease the risk of myomas possibly by decreased estrogen levels .
Pathology :
Myomas originate from somatic mutation in myometrial cells leading to loss of growth regulation .Myomas are uterine in 99% , 95% are corporeal and 4% are cervical (usually single) . Fibroids arise in the round ovarian, or uterosacral ligaments or even from the smooth muscles between the layers of the broad ligament (1%) .
Uterine fibroids start interstitial ( intramural which is the commonest type = 60 % ) submucous subserous which may become pedunculated .
Grossly , Fibroids are variable in size, with smooth pale outer surface and firm in consistency . On cut section , it has whorly appearance , is paler than the surrounding myometrium due to poor vascularity and is surrounded by a capsule composed of compressed normal uterine muscles ( false capsule ) . Fibroids receive their blood supply from vessels originating in the capsule and passing inwards in the tumor .
Hyaline degeneration starts in the center ( very poor vascularity ) .
Calcium deposition ( calcification ) starts at the periphery .
Necrosis of the tip of fibroid polyp .
Microscopically , there are bundles of smooth muscle cells intermingled with fibrous tissue .
Pathological effects of fibroids on the pelvic organs :
I- Uterus :
1. Increased vascularity .
2. Increased surface area of the endometrium due to increase uterine size .
3. Very rarely fundal submucous fibroid polyp may lead to chronic inversion .
4. A large cervical fibroidcauses upward displacement of the body of the uterus .
5. Cervical enlargement , elongation , tortuisity and obstruction of the canal .
II- Adnexa :
Elongation and stretching of the tube may occur if there is large board ligament fibroid .Cornual fibroids may result in tubal obstruction .
III. Urinary organs :
Pressure on the bladder leading to frequency of micturition .Marked compression of the urethra leading to retention of urine .
Displacement and pressure on the ureter leading to hydroureter and hydronephrosis .
Urinary stasis resulting in increased risk of UTI .
Secondary pathological changes occurring in fibroids :
I- Degenerative changes ( occur in 2/3 of myomas ) :1. Atrophy ( diminution in size ) : Occurs after menopause due to diminution of the blood supply . Decrease in size also occurs during the pureperium following the rapid enlargement during pregnancy .
2. Necrosis : Results from complete cutting of the blood supply .
3. Hyaline degeneration :
* Occurs specially in the center of large tumors due to poor blood supply .
* The whorled appearance is lost and the affected area is replaced by homogenous structureless hyaline material .
4. Cystic degeneration :
* This may be due to :
a. Liquefaction of the hyaline material .
* The tumor becomes soft or cystic in consistency .
5. Red degeneration ( necrobiosis or carneous degeneration ) .
* It is incomplete necrosis from which the tumor is capable of recovery commonly met with in fibroids accompanying pregnancy .
* The frequency of necrobiosis during pregnancy is due to the following which predispose to thrombosis of the vessels of the capsule .
a. Congestion .
b. Kinking of the blood vessels of the capsule due to rapid growth .
c. The hypercoagulable state of pregnancy .
* The cut surface is red in color due to diffusion of blood pigments through the tumor and the freshly cut tumors have a fishy odor .
* Clinically , there is acute abdominal pain , rapid pulse , mild pyrexia , vomiting and the tumor is tender .
* Treatment during pregnancy is conservative and consists of rest and sedatives . Pain is persistent or increasing , do myomectomy removing only the affected tumor .
6. Fatty degeneration : Deposition of fat in the tumor cells which make the tumor yellowish and softer . It is a precursor to calcification .
7. Myxomatous degeneration of the myoma .
8. Calcification : Calcium salts are mainly deposited at the periphery along the course of the blood vessels . The tumor becomes hard and gives an X-ray shadow like egg-shell appearance . If the tumor is vascularized , diffuse calcification is noticed .
II- Malignant change ( Sarcomatous change starting centrally ) :
* Suspected of there is :
1. Rapid enlargement of the tumor .
2. Post-menopausal growth .
3. Post-menopausal bleeding . Postmenopausal bleeding in a cases with fibroid is considered sarcomatous changes until proved otherwise .
4. Rapid recurrence of fibroid polyp after removal .
III- Vascular changes :
1. Congestion from torsion .2. Edema due to Impaction , torsion or infection .
Complications :
1. Torsion of a pedunculated subserous fibroid .2. Rupture of a surface vein of subserous fibroid causing internal hemorrhage .
3. Infection : Necrosed tip of a submucous fibroid polyp .
4. Degeneration causing pain as red and hyaline degeneration .
5. Malignant change .
6. Chronic inversion of the uterus in cases of submucous fundal fibroid .
7. Impaction of the fibroid ( incarceration ) . This may occur with cervical fibroid and subserous fibroids on the posterior wall .
8. Urinary compression .
9. Torsion uterus .
10. Anemia in cases with bleeding .
Diagnosis :
I. Risk factors :
1. Racial and familial history .
2. All hyperestrogenic states .
II. Symptoms :
1. Asymptomatic ( accidental discovery ) .2. Menorrhagia .
a. Increased vascularity of the uterus .
b. Increased surface area of the endometrium .
c. Endometral hyperplasia .
3. Infertility ( 30 % of cases )
a. Submucous fibroid preventing implantation of the fertilized .b. Bilateral tubal obstruction .
d. Hormonal disturbance present and the associated anovulation .
4. Metrorrhagia due to :
a. Necrosed tip of a submucous fibroid polyp .b. Infected submucous fibroid .
c. Malignant change of the fibroid .
5. Congestive dysmenorrhea .
6. Leucorrhea : Due to pelvic congestion . Offensive discharge occurs with infected submucous polyp .
7. Abdominal mass .
8. Pain :
a. In uncomplicated tumors , it is uncommon expect for colicky pain .b. Pain is a symptom of complications as :
i- Hyaline degeneration ( dull ache ) .
ii. Red degeneration ( pain and vomiting ) .
iv. Torsion of a pedunculated subserous fibroid . ( acute pain ) .
iii. Infection ( pain and pyrexia ) .
v. Malignant change ( spread ) .
9. Pressure symptoms :
a. Frequency of micturition due .b. Retention of urine .
c. Pressure on nerves will give various types of pain associated with peripheral neural symptoms .
III. Signs :
1. Pelvic-abdominal mass :2. Pelvic mass :
IV. Special investigations :
Although no pathognomonic sign of fibroid , TAS or TVS can determine the type size , site number and pathological changes specially during pregnancy ( however , the best is MRI ) .
Hysterosalpingography to diagnose submucous fibroid and to detect the condition of the tubes before myomectomy .
Intravenous pyelography specially .
Dilatation and curettage should be done in cases presenting by metrorrhagia .
Differential Diagnosis :
Large fibroids should be differentiated from other causes of pelviabdominal swellings .Treatment :
I- Expectant treatment :* Treatment entails follow up every 6 months .
* Indicated in small asymptomatic tumors .
1. If the fibroid is larger than the size of 12 week pregnancy .
2. Rapidly growing fibroid ( suspicion of malignant change ) .
3. Subserous pedunculated fibroid ( torsion is liable to occur ) .
4. A fibroid distorting the uterine cavity a young nulliparous patients ( as it may lead to infertility or habitual abortion ) .
I. Symptomatic treatment :
* Indicated for patients near menopause who have an interstitial fibroid with slight menorrhagia .* treatment of bleeding , treatment of anemia .
III- Surgical treatment ( The standard line ) :
1. Myomectomy :
* Definiton : Surgical removal of fibroids without removal of the uterus .
* It is indicated in all cases before 40 Ys age whenever possible .
* Types :
a. Abdominal : i. Through laparotomy . ii. Through laparoscopy .
b. Vaginal :
i. Polypectomy with or without hysteroscopic guide .
ii. Through hysterotomy ( not done now ) .
* Advantages : The uterus is preserved and so pregnancy can occur .
* Disadvantages :
a. Higher mortality rate than hysterectomy due to the risk of bleeding from the tumor bed .
b. Menorrhagia may persist after myomectomy due .
c. Recurrence of fibroids which may be due to missing of small seedling fibroids or the growth of new tumors .
d. Adhesions to the scar in the uterus particularly if the incision is done in the posterior wall .
e. Rupture of the scar may occur in the subsequent pregnancy .
* Contraindications = Indications of hysterectomy .
2. Hysterectomy :
* Indications :1. Patients over 40 years .
2. Very large number of fibroids so that the uterus left will be useless .
3. Suspicion of malignancy .
4. Bilateral poysalpinx .
5. A large interstitial cervical fibroid .
* Total hysterectomy is the operation of choice :
3. Uterine artery embolization : Using polyvinyl alcohol particles or gel foam pellets to induce degeneration of the tumor has been recently tried in selected cases with symptomatic fibroids . Bilateral uterine artery ligation is also tried as an alternative to embolization .
IV- Medical treatment :
* The aim of this line is to create a state of hypoerstrogenism or carry out antiestrogenic action to deprive the tumor from the stimulus of growth .* Indications :
1. When the surgical line is not available .
2. Before surgery to decrease the tumor size and vascularity making surgery easier , less bloody and with minimal postoperative adhesions .
* Medical treatment is only suppressive and dont cure the tumor , so its effect is temporary .
* The most commonly used drugs are :
1. Danazol 2. Gestrinone 3. GnRH 4. RU4865. Large dose progesterone ? 6. Small doses of androgens .