Uterine leiomyomas (ie, fibroids or myomas) are benign clonal tumors arising from the smooth muscle cells of the uterus and containing an increased amount of extracellular matrix proteins (collagen and elastin). They are surrounded by a thin pseudocapsule of areolar tissue and compressed muscle fibers.
Myomas are clinically apparent in approximately 25 percent of reproductive aged women and noted on pathological examination in approximately 80 percent of surgically excised uteri( UpToDate professional-level topic review )
3-9 times more frequent in black than in white women
leiomyoma of uterus
Usually multiple, discrete, either spherical or irregularly lobulated;
Have a false capsular covering, and clearly demarcated from the surrounding myometrium;
The consistency is usually firm or even hard except when degeneration or hemorrhage has occurred;
color ： light gray or pinkish white;
cut section ： an intertwining pattern or a whorl-like arrangement ； bulgy.
Composition ： smooth muscle, connective tissue
The nonstriated muscle fibers are arranged in bundles of various sizes that run in multiple directions.
Individual cells are spindle shaped, have elongated nuclei, and are uniform in size. varying amounts of connective tissue are intermixed with the smooth muscle bundles.
According to growth location ：
Myomas on the body of uterus （ 90% ）
Myomas on the cervix of uterus （ 10% ）
According to the relation to uterine muscle ：
Submucous leiomyomas （ 10 ～ 15% ）
Intramural leiomyomas （ 60 ～ 70% ）
Subserosal leiomyomas （ 20% ）
Subserosal uterine fibroids
These fibroids originate from the serosal surface of the uterus. They can have a broad or pedunculated base and may be intraligamentary (ie, extending between the folds of the broad ligament).
Intramural uterine fibroids
The most common type of fibroid. These develop within the uterine wall and expand making the uterus feel larger than normal (which may cause "bulk symptoms"). They may enlarge sufficiently to distort the uterine cavity or serosal surface. Some fibroids can be transmural and extend from the serosal to the mucosal surface.
Submucosal uterine fibroids
These fibroids develop just under the lining of the uterine cavity. These neoplasms often protrude into the uterine cavity. These are the fibroids that have the most effect on heavy menstrual bleeding and the ones that can cause problems with infertility and miscarriage.
There are three primary types of uterine fibroids, classified primarily according to location in the uterus
Smooth muscle tumors of the uterus are often multiple. Seen here are submucosal, intramural, and subserosal leiomyomata of the uterus.
the secondary infection
at menopause or after pregnancy, tumor size shrink, so the sign
Occasionally seen as a complication of pregnancy （ during pregnancy or immediate postpartum period ）
The pathogenesis is unknown ， may be the result of the accumulation of blood in the tumour because of venous obstruction.
The cut surface resembles raw meat.
Clinical features ： a cause of pain （ acute ）
rapid growth ， tender
Here is a very large leiomyoma of the uterus that has undergone degenerative change and is red (so-called "red degeneration"). Such an appearance might make you think that it could be malignant. Remember that malignant tumors do not generally arise from benign tumors.
Rare ： 0.4% ～ 0.8%
More common at 40 ～ 50 years old
Usually occur in intramural fibroids
The majority of fibroids are small and do not cause any symptoms at all. However, many women with fibroids have significant bleeding and/or pain that interfere with some aspect of their lives.
The severity of symptoms is related to the number, size, and location of the fibroids, and fall into three main groups: increased uterine bleeding, pelvic pressure and pain, and problems related to pregnancy and fertility. The symptoms tend to decrease at the time of menopause, although women who take hormone replacement may not see this effect.
menorrhagia and prolonged menstrual period ： common
Pelvic pain ：
occurs in pregnancy if undergoing degeneration or torsion of a pedunculated myoma
Pelvic pressure ： urinary frequency
bowel difficulty （ constipation ）
Increased uterine bleeding — Fibroids can cause an increase in the amount of blood flow and length of a woman's menstrual period. The presence and amount of uterine bleeding is determined mainly by the location and size of the fibroid. Women with fibroids that protrude into the uterus are more likely to have significant increases in bleeding, although women with all types of fibroids can have this problem. If the bleeding is very heavy, anemia can occur.
Pelvic pressure and pain — Fibroids can range in size from microscopic to the size of a grapefruit or even larger. Larger fibroids may cause a sense of pressure and fullness in the abdomen, similar to that caused by pregnancy. Fibroids of variable sizes can cause other symptoms, depending upon where they are located within the uterus. As an example, if the fibroid is pressing on the bladder, frequent urination or difficulty emptying the bladder can occur. A fibroid near the rectum may cause constipation, and cervical fibroids can cause pain during sexual intercourse.
In rare cases, fibroids can cause sudden and severe pain if the fibroid begins to break down (degenerate) or twist. Pain of this type may be associated with a mild fever, tenderness in the abdomen, and elevation in the white blood cell count. The pain usually resolves in a few days to weeks. Nonsteroidal anti-inflammatory drugs, such as ibuprofen, can be used to treat the discomfort.
Problems with pregnancy and fertility
— Some studies have suggested a slightly increased risk of problems during pregnancy in women with very large fibroids, including breech presentation, premature rupture of membranes, premature labor, and placental abruption (a condition in which the placenta separates prematurely from the uterine wall). In addition, women with very large fibroids are at a high risk of cesarean delivery. These problems are more likely if the placenta is implanted over the area of the large fibroid. Nevertheless, nearly all women with fibroids have completely normal pregnancies without complications.
The risk of miscarriage and infertility is associated with a type of fibroid that protrudes into the uterine cavity. Typically these fibroids can be easily removed using a hysteroscope (a small telescope-like device inserted through the cervix into the uterus), which reduces this risk.
However, it is not completely clear what role that fibroids play in infertility. An infertile woman who has large or numerous fibroids may want to talk with her doctor about having the fibroids removed, although all other causes of infertility should first be eliminated.
A palpable abdominal tumour
Pelvic examination ：
uterus — enlarged and irregular ；
Fibroids are often diagnosed during a routine pelvic exam. A clinician may feel the enlarged, irregular outline of the uterus through the abdomen. In certain cases, the clinician may wish to confirm the diagnosis of fibroids and exclude other types of masses. Ultrasound is generally preferred, and uses sound waves to visualize the uterus
（ B – ultrasound examination ）
Malignant tumors of uterus
sarcoma of uterus
In women who have no symptoms from their fibroids, treatment is usually not required. In women with significant symptoms, treatment may be medical or surgical.
Observation and Follow Up
Small ， asymptomatic fibroids need not be treated ， especially near menopause.
Interval ： 3 ～ 6 months
Androgenic agents ： testosterone propionate
induce a hypoestrogenic pseudomenopausal state
not recommended for longer than 6 months
“ add-back” regimens
Medical treatment includes the use of medications to treat the symptoms of fibroid-related bleeding and pain. Gonadotropin-releasing hormone (GnRH) agonists are the most common medical treatment for fibroids. Most women who use GnRH agonists temporarily stop having menstrual periods and have a significant reduction in the size of their fibroid(s). Reducing or eliminating menstrual bleeding can improve anemia.
However, fibroids rapidly enlarge after GnRH agonists are discontinued. In addition, there are some significant side effects after long-term use, including bone loss leading to osteoporosis. GnRH medications are usually given as a temporary measure (usually no longer than six months), such as while a woman is preparing for surgical treatment. In some cases, using a small dose of estrogen can minimize the side effects of GnRH agonists.
Danazol is an androgenic steroid, and may be used to stop menstrual bleeding. Danazol may be used when it is not necessary to shrink the size of the uterus or for women who cannot take GnRH-agonists. Use of Danazol is generally limited due to bothersome side effects, including weight gain and mood changes.
greater than 10 weeks’ gestational size
menorrhagia ， lead to anemia
have pressure symptoms
failure of medical treatment
significant risk of recurrence
Hysterectomy— radical therapy
Uterine artery embolization
Only true “cure” for leiomyomas
laparoscopic or hysteroscopic
In most women, surgical treatment is used to provide relief from fibroid symptoms. In other cases, surgical procedures are done in an attempt to treat infertility. A number of surgical treatments are available.
Hysterectomy — Hysterectomy is surgical removal of the uterus through the abdomen or vagina. It may be the treatment of choice for some women who have completed childbearing, are not interested in other surgical treatments, and who have severe symptoms. Removal of the ovaries and cervix is not necessary for symptom relief.
Myomectomy is surgical removal of a fibroid. preserves the chance of future childbearing and may provide short-term relief of heavy bleeding, but is associated with a significant risk of recurrence. Between 10 and 25 percent of women who have myomectomy will require a second surgery. In addition, abdominal and laparoscopic myomectomy slightly increase the risk of uterine rupture during pregnancy or labor; the risk for most women is small.
Endometrial ablation — In this procedure, the lining of the uterus is destroyed with heat by a scope inserted into the vagina through the cervix and into the uterus. It can be done alone, or in combination with other treatments such as hysteroscopic myomectomy or myolysis (explained below). Normal pregnancy is possible, though not recommended after endometrial ablation; contraception is strongly recommended since a woman continues to ovulate. Endometrial ablation decreases bleeding without affecting uterine size.
Uterine artery embolization — In uterine artery embolization (UAE or UFE), a small catheter is inserted in a large blood vessel and threaded up to blood vessels near a fibroid. Tiny particles are injected into the blood vessel, which stops blood flow to the fibroid. This causes the fibroid to rapidly decrease in size within days to weeks after UAE.
Diagram showing superselective catheter position in the right uterine artery via left femoral arterial approach.
Diagram showing embolic particles being released from the catheter and into the uterine arterial branches supplying the fibroid.
It is important to individualize the choice of therapy .
Uterine Leiomyomas Complicating Pregnancy
impact on pregnancy ： abortion
impact on delivery ： premature labour
need for operative delivery
（ birth canal obstruction ）
May be related to superabundant estrogen.
Well-circumscribed,have a pseudocapsule.
Can be classified into submucosal,intramural and subserosal types.
Different types have different features.
Menorrhagia is common.
Four degeneration types
Individualized treatment ， include observation 、 medical treatment and surgical treatment.