UTERINE FIBRIOD:
This is a benign growth from the muscular layer of uterus. They arise from the muscles of the uterine wall (myometrium).
Myomas are also called as fibroids, lieomyomas or myomas.
Incidence:
• It has been estimated that at least 20% of women at the age of 30 have got fibroid in their wombs.
• The prevelence is highest between 35 – 45 years of age.
• Fibroids are associated with infertility and nulliparity.
• Leiomyomas are more common in African – Americans than in American women.
Aetiology:
1.Oestrogens:
The development of fibroid during reproductive period appears to be due to oestrogen dependent and increased blood supply of uterus.
Presence of oestrogen receptors is higher in myomas. After menopause the growth of the tumor stops and some regression in size may take place.
2.Mechanical stresses :
Myomas are fibromuscular reactions to mechanical stresses in the uterine wall operating in a uterus not protected by pregnancy.
3.Racial and genetic factors:
Africans are more prone to develop myomas. They are also reported to have familial incidence.
4.Parity : Myomas are more common in nulliparous women, or women of low parity, but the cause and effect relationship is not established.
5.Women who are over weight or obese also are at a slightly higher risk for fibroids than women who are not overweight.
6.Use of oral contraceptives and oestrogen replacement therapy ( ERT) may cause excessive growth of fibroids.
LOCATION:
• Corporeal body is commomest.
• Cervical (1-2%)
Types:
•INTRAMURAL ( Interstitial) :
It is the commonest type of tumor ( about 60%). Posterior wall of the uterus is the commenest site for this tumor formation.
It grows in the subtance of the uterine wall. It may be that all fibromyomas commence as interstitial growth, gradually becoming either submucous or subserous. Can range in size from microscopic to larger than a grape fruit.
•SUB SEROUS ( Sub peritoneal):
The tumor lies underneath the peritoneaum and may be sessile or pedunculated.Very rarely, a pendunculated tumor may acquire adhesion with surrounding structures and get detached from the uterine wall, they are called parasitic fibroids or wondering fibroids.
Rarely, the rupture of the subperitoneal vein on the subserous fibroid may cause severe intraperitoneal haemorrhage.
•SUB MUCOUS:
The tumor grows underneath the mucous membrane of the uterus and projects inside the uterine cavity.
The facts of the submucous fibroid are the following :
a) Sub mucous fibroid polypus formation.
b) Chance of infection, suppuration and sloughing.
c) It becomes prone to undergo malignant change than any other variety.
d) It may rarely cause inversion of the uterus during the expulsion.
They constitute about 5% of all myomas, but are more likely than either of the other varieties to cause profuse bleeding and to require hysterectomy, even though small.Their presence can be detected by feeling of “bump” over the protruding surface, although they are generally too firmly embedded to be removed by the curette.
Pathology:
Myoma may be single or multiple (usually 5-30); upto 200 have been reported in a single uterus. Their size is variable from few millimeters to the size of a football, filling whole of the abdomen.
Leiomyomas often multiple,lobulated, circumscribed firm, nodular, grey white masses of variable size. The tumor is surrounded by a psuedocapsule which is formed by compression of the myometrial tissue surrounding the myoma.
Cut section: Shows a characteristic pale white appearance with whorl- like trabeculations. The center of growth is more pale than that of the periphery due to less vascularity
Clinical features:
The patients are usually nulliparous or having long period of secondary infertility.
However, early marriage and frequent childbirth makes its frequency high even amongst the multiparous women.
*There is tendency towards delayed menopause.
Symptoms:
Abnormal uterine bleeding: The bleeding pattern most characteristic of myomas is menorrhagia or hypermenorrhoea.
Metrorrhagia( irreguar bleeding) is not characteristics of myomas.
The obstructive effect on uterine vasculature created by intramural myomas leads to endometrial venule ectasia. Which results in congestion of myometrium and endometrium leading to profuse bleeding. Also increased size of uterine cavity and surface area of the endometrium may contribute to it.
• Menorrhagia ( profuse bleeding): This is most commonest symptom with passage of clots.
• Anaemia: The heavy bleeding can cause iron deficiency anaemia.
• Pelvic mass: Few patients may seek advice for a painless mass in lower abdomen which is increasing in size very slowly. The mass causes a sensation of heaviness in the lower abdomen.
Pubic pressure:
•Urinary frequency : This is due to mechanical irritation and reduced capacity of the bladder.
•Urinary incontinence} An impacted myoma in the pelvis may cause acute retention of urine and then overflow incontinence by pressing on the bladder neck .This is more likely to happen with cervical myomas
• Difficulty in urination
Ureteral obstruction with hydronephrosis
Gastrointestinal Tract: The pressure effects are on the G.I.T are less conspicuous.In exceptional cases, if myomas are very large, they may cause dyspepsia( due to mechanical irritation of stomach), intestinal obstruction and constipation.Tenesmus may be the result of a posterior wall myoma exerting pressure on the rectosigmoid.
Parity : Infertility is commonly associated with myomas. The majority of patients are either nulliparous or of low parity.
Uterine myomas have been reported in 21% of infertile women.
In these patients, the operating mechanism may be infrequent ovulation, abnormal uterine or tubal motility or sperm transport and abdominal uterine blood flow.
Pain lower abdomen: Pain is usually associated with torsion of the pedicle of a pedunculated myoma. Spasmodic dysmenorrhoea occurs with interstitial and submucous fibroids or a fibroid polyp.
Veins and lymphatics :
Pressure effects on the veins may produce oedema and varicosities of the legs.
Vaginal discharge: Blood stained discharge is seen with an infected fibroid protruding through the cervical canal.
Pregnancy related:
•Myoma growth: When an increase in size is detected, most of the growth takes place in the early pregnancy after which either they remain stable or decrease in size.
•Red degeneration and pain: Uterine myoma mainly cause pain during pregnancy. Pain is mostly related to the red degenaration ( necrobiosis ) of myomas, although it may be the result of torsion or fibroid impaction.
• Miscarriage: Uterine myomas may increase the risk of spotaneous miscarriage during the early pregnancy.
Anaemia
Ascites due to pseudomeige syndrome.
Signs:
1. Anaemia is present where there is excessive bleeding.
2. Per Abdomen : A firm irregular lump can be palpated arising out of the pelvis.
The surface of the lump may be smooth; the lump shows dullness on percussion.
The tumor is mobile laterally but not from above down wards. There is no tenderness, unless the myomas are complicated by an associated disease or degeneration.
Pelvic Examination:
Bimanual Examination:
Uterus is not felt seperated from the swelling and as such a groove is not felt between the uterus and the mass.
The cervix moves with the movement of the tumor felt for abdomen.
Rectal Examination:
Can also better explore the pelvic cavity
Clinical complications:
1.Red degeneration:The patient complaints of acute abdominal pain over the tumor with fever and vomiting.
Intravenous fluid and sedation will settle the symptoms in 2-4 days time.
2.Sarcoma :
It is mainly noticed in a post menopausal woman who presents with a sudden growth of the fibroid, pain and postmenopausal bleeding. The interstial and submucous fibroids are more liable to undergo malignant change than the subserous fibroid.
3.Torsion of a pedunculated fibroid: Causes acute abdominal pain and vomiting. A tender swelling is felt in the abdomen.
4.Calcification: Calcified fibroid presses against the bladder and rectum causing pain and pressure symptoms. X- ray will reveal a calcified tumor.
5. Capsular haemorrhage:It is rarely reported to cause internal haemorrhage. Blood transfusion will be needed to replace the blood.
6. Infection: Infection is invariably noticed in a submucous fibroid or mucoid polyp protruding through the dialated cervix. This causes blood stained purulent discharge.
The worst infection is seen in the puerperium when a woman develops fever, offensive vaginal discharge and secondary post partum haemorrhage pyomyoma ( suppurative myoma) with septic shock has been reported in the peuperium.
7.Inversion uterus: Occurs only with submucous fundal fibroid polyp.
Obstetric Complications:
a.Abortion in case of a submucous and interstitial fibroid:
A large submucosal fibroid that projects into the uterine cavity, may compress the underlying endometrium and lead to endometrial dsfunction or it may distort the muscular architecture that supplies and drains the endometrium at that site. If the embryo chosses to implant at that site, the fibroid may interfere with normal placentation and development of the definitive utero placental circulation and lead to spontaneous pregnancy loss.
Threatened abortion.
b.Acute retention of urine in the first trimester if the fibroid gets impacted in the pouch of douglas.
c.Red degeneration of fibroid.
d.Malpresentation:Increased prevalence of malpresentation only if the uterus had multiple fibroids or if there was a fibroid located behind the placenta or in the lower uterine segment. Abnormal presentation like transverse lie.
e.Preterm labour and birth:Preterm birth was reported with fibroids larger than 3 cms and 6 cms in diameter as compared with controls. Decreased oxytocinase activity in the gravid fibroid uterus, which may result in a localised increase in oxytocin levels and predisposition to premature contractions.
f.Preterm Premature rupture of mebrane: The greatest risk for PROM seems to be in women in whom the fibroid is in direct contact with the placenta.
g.Placental abruption: The blood flow is reduced significantly in fibroids and in the myometrium adjacent to fibroids. Therefore, implantation in the endometrium overlying a fibroid may lead to placental ischaemia and decidual necroisis, which makes it more susceptible to abruption.
h. Placenta Previa: The presence of uterine fibroids was believed to lead to preferential placentation in the lower uterine segment.
i.Pain: Painis one of the most frequent complications of fibroid in pregnancy. Fibroid pain likely results from decreased perfusion in the setting of rapid growth leading to ischaemia and necrosis( degeneration) with release of prostaglandins.
j.Preeclampsia : Women who had multiple fibroids were likely to develop preeclampsia than were those who had a single fibroid. It has been told that increased risk was due to disruption of trophoblast invasion by the multiple fibroids which leads to inadequate uteroplacental vascular remodelling and ultimately predisposes the patient to the lateral development of preeclampsia.
k.Uterine inertia in case of interstial fibroids.
l.Obstructed labour due to tumor presenting before the presenting part or due to transverse lie.
m.Intra uterine growth restriction women who had uterine fibroids delivered at earlier gestational ages than did the control group.
n.Fetal anomalies: The dominant leision in the fibroid cases was caudal dysplasia.
o.Dysfunctional labour:Fibroids decrease the force of uterine contractions and also disrupt the co-ordinated spread of the contractile wave and there by, lead to dysfunctional labour.
p.Caesarean delivery: There is increased risk of caesarean delivery if the fibroids were located in the lower uterine segment.
q.Primary as well as secondary post partum haemorrhage:
Fibroids may predispose to postpartum haemorrhage by decreasing the force and coordination of uterine contractions, which leads to uterine atony.
which leads to uterine atony.
INVESTIGATIONS:
•To Confirm the diagnosis:
Ultrasound: It is useful diagnostic tool to confirm the diagnosis of uterine fibroid and to differentiate, it from ovarian mass or pregnancy.
