What Is a Uterine Leiomyoma?

Uterine leiomyoma is abbreviated as uterine fibroids. It is the most common benign tumor of female reproductive organs. It is common in women between 30 and 50 years of age and is rare under 20 years of age. According to statistics, at least 20% of women of childbearing age have uterine fibroids. Since most uterine fibroids have no or few clinical symptoms, the clinically reported incidence is far lower than the actual incidence of fibroids. Since uterine fibroids are mainly formed by the proliferation of uterine smooth muscle cells, a small amount of fibrous connective tissue exists as a supporting tissue, so it is more accurately called uterine leiomyoma. Referred to as uterine fibroids.

Basic Information

English name: leiomyoma uteri, uterine leiomyoma
Visiting department: Gynecology, Oncology
Multiple groups: 30 to 50 year old women

Common causes: Maternal estrogen use during pregnancy, young menarche, non-fertility, late fertility, obesity, African Americans, tamoxifen, etc.
Common symptoms: Increased menstrual flow and prolonged menstruation, lower abdominal mass, increased vaginal discharge, compression symptoms, etc.

Causes of uterine leiomyoma

So far, the etiology and pathogenesis of uterine fibroids are unclear and may be related to the following aspects.

The risk factors that contribute to the occurrence or growth of uterine fibroids are many. Factors that increase the risk of uterine fibroids include: maternal estrogen use during pregnancy, young menarche, infertility, late fertility, obesity, African Americans, tamoxifen and so on. Factors that reduce the risk of uterine fibroids include exercise, fertility, menopause, oral contraceptives, etc.

Sex hormones and their receptors

Modern medicine regards uterine fibroids as hormone-dependent tumors. Uterine fibroids occur prematurely, are rare before puberty, and shrink or disappear after menopause. Research suggests that estrogen and progesterone synergistically promote fibroid growth. The main mechanism may be that estrogen in the follicular phase up-regulates the estrogen and progesterone receptors on uterine smooth muscle, and then progesterone promotes mitotic activity of fibroids during the luteal phase, thereby stimulating the growth of fibroids.

2. Genetic factors

Cytogenetic studies have shown that 25% to 50% of uterine fibroids have cytogenetic abnormalities, including swapping of chromosome 12 and chromosome 17 fragments, rearrangement of chromosome 12, and partial deletion of chromosome 7.

3. Cytokines and extracellular media

Uterine fibroids have increased expression levels of multiple growth factors and their receptors. They are considered to be mediators or effectors of ovarian sex hormones during the formation of uterine fibroids, but primary regulation of one or more growth factors cannot be ruled out. Abnormal possibility. Uterine fibroids usually contain too many extracellular media, which mainly contain fibroblasts and collagen types I and III. Fibroid cells interact with fibroblasts and various growth factors to form fibroids. Formation and growth provide a suitable microenvironment.

Current molecular biology studies suggest that uterine fibroids are proliferated from monoclonal smooth muscle cells, and multiple uterine fibroids are formed from different cloned cells. It is unclear whether the factors described above play different roles in the formation of different clones.

Classification of uterine leiomyoma

Uterine fibroids are divided into uterine fibroids (92%) and cervical fibroids (8%) according to the location of the fibroids. According to the relationship between fibroids and uterine muscle wall, it can be divided into intermural fibroids, subserosal fibroids and submucosal fibroids.

Multiple or multiple types of fibroids can occur in the same uterus and are called multiple uterine fibroids.

Clinical manifestations of uterine leiomyoma

Symptoms

Most uterine fibroids are asymptomatic and are only found by accident during a physical examination. Symptoms are related to fibroid location, size, and presence or absence of degeneration. Common symptoms are:

(1) Increased menstrual flow and menstrual period are more common in large intermural myomas and submucosal fibroids. Fibroids enlarge the uterine cavity, increase the endometrial area, and affect menstrual contraction and hemostasis. In addition, fibroids may cause The veins near the tumor are squeezed, causing congestion and expansion of the uterine venous plexus, which leads to increased menstrual flow and prolonged menstruation. The symptoms of submucosal fibroids are more pronounced. Such as submucosal fibroids with necrotic infection, there may be irregular vaginal bleeding or bloody purulent drainage. Increased long-term menstrual flow can be secondary to anemia, symptoms such as fatigue, palpitations.

(2) The mass of the lower abdomen is not felt in the abdomen when the fibroid is small. When the fibroid gradually increases and the uterus is more than 3 months pregnant, it can reach the hard mass from the abdomen, which is more obvious when lying flat in the morning. Giant submucosal fibroids can prolapse outside the cervix and even outside the vagina.

(3) Increased leucorrhea The myometrial fibroids increase the area of the uterine cavity, increase endometrial secretion, and increase leucorrhea with pelvic congestion. Once submucosal fibroids are infected, there can be a large number of purulent leucorrhea. If fibroids have ulcers, necrosis, or bleeding, they may have bloody or purulent, malodorous vaginal discharge.

(4) Compression symptoms Fibroids in the anterior wall of the uterus, such as compression of the bladder, can cause frequent urination and urgency; cervical fibroids can cause dysuria and urinary retention; posterior wall fibroids can cause symptoms such as lower abdominal distension, constipation and other symptoms. Broad ligament fibroids or cervical giant fibroids develop laterally, embedded in the pelvic cavity, and compressing the ureter, which can form ureteral dilatation, hydronephrosis, and even one side of the kidney is nonfunctional.

(5) Other common symptoms are slight lower abdomen swelling, backache, etc., which can be worse during menstruation. Can cause infertility or miscarriage. Fibroids have acute lower abdominal pain during red degeneration, accompanied by vomiting, fever, and local tenderness of the tumor; subserosal fibroids may have acute abdominal pain when twisted; uterine submucosal fibroids can also cause paroxysmal discharge Lower abdominal pain and so on.

2. Signs

The patient's signs are diverse, which is related to the size, location, number and degeneration of myoma. Larger fibroids can lie in the lower abdomen with a solid mass. Gynecological examination The uterus is enlarged with irregular single or multiple nodular processes on the surface. Subserosal fibroids can be connected to the uterus with a single solid mass. The submucosal fibroids in the uterine cavity often enlarge evenly. If the fibroids have prolapsed from the external mouth of the cervix, speculum examination can see the dilation of the cervix, the pink solid mass protruding from the cervix, the surface is smooth, The edges around the cervix are clear. If accompanied by infection, the tumor may have necrosis, bleeding, and purulent secretions.

Uterine leiomyoma

1. Transvaginal ultrasound (TVS)

It is the most commonly used non-invasive test for diagnosing uterine fibroids. Under ultrasound, the uterus enlarges and is irregular in shape. The fibroid nodules are round low echoes or iso-echoes. There is a hypoechoic halo formed by a pseudocapsule. Tumors appear as abnormal echoes in the uterine cavity, which are classified into 0-2 types according to their relationship with the muscle wall. Color ultrasound Doppler can detect the blood flow of the lesion and is of great value in assisting in judging fibroid degeneration and even malignancy.

2. Hysteroscopy

Hysteroscopy is a relatively simple and minimally invasive examination and treatment method for patients with suspected submucosal fibroids.

3. Laparoscopy

Laparoscopy is not a routine diagnostic method for uterine fibroids because most uterine fibroids can be diagnosed by ultrasound and only subserosal fibroids can be detected by laparoscopy. However, for other reasons, laparoscopy can be performed on the uterine surface at the same time.

4. Uterine fallopian tube angiography

It is not used as a routine method of uterine fibroids examination, but when performing hysterosalpingography due to infertility or other reasons, it is possible to find intermuscular or submucosal fibroids that cause uterine deformation.

Uterine leiomyoma diagnosis

According to the patient's medical history and signs, the diagnosis is more or less difficult. Individual patients have difficulty in diagnosis. B-ultrasound, hysteroscopy, laparoscopy, hysterosalpingography can be used to assist diagnosis.

Differential diagnosis of uterine leiomyoma

Pregnancy uterus

Enlarging and softening, threatened abortion often appears as irregular bleeding, and sometimes physical examination may be confused with cystic fibroids. However, pregnant women have a history of menopause and early pregnancy reactions, and the uterus becomes softer with menopause. The diagnosis can be confirmed with the help of urine or blood -HCG measurement and B-ultrasound.

Ovarian tumor

Sometimes it can cause compression symptoms such as frequent urination, constipation, and abdominal mass. However, most ovarian tumors have no menstrual changes, and most of the masses are cystic on the side of the uterus when examined. However, attention should be paid to the identification of solid ovarian tumors (especially interstitial tumors that can cause changes in hormone levels and cause abnormal uterine bleeding) and pedicled subserosal uterine fibroids. Diagnosis can be assisted by ultrasound, laparoscopy, etc.

3. Adenomyosis

There may also be ovarian manifestations such as increased menstrual flow and enlarged uterus. However, adenomyosis has a history of secondary progressive dysmenorrhea, and the uterus tends to grow uniformly, rarely exceeding the size of a 3-month pregnancy, and changes in uterine size before and after menstruation. A B-ultrasound helps diagnosis. But sometimes the two can coexist.

4. Other

Ovarian endometriosis cysts, pelvic inflammatory masses, and uterine malformations can be identified based on medical history, clinical manifestations, and B-ultrasound.

Uterine Leiomyoma Treatment

Treatment should be based on the patient's age, fertility requirements, symptoms, and location, size, and number of fibroids to achieve individualized treatment.

Follow-up observation

Asymptomatic small uterine fibroids generally do not require treatment, especially in perimenopausal women. Postmenopausal uterine fibroids may gradually shrink and even disappear. Can be followed up every 3 to 6 months.

2. Drug treatment

Short-term treatment is mainly used for patients with uterine fibroids with surgical indications. Preoperative medications are used to correct anemia, reduce uterine volume, avoid intraoperative bleeding, and reduce surgical difficulties. In near-menopausal women, the uterus is smaller than 10 weeks of pregnancy. Symptoms are mild; those who have surgery contraindications due to other complications. Due to the side effects of the drugs used, it should not be used for a long time.

(1) GnRH-a analogs (GnRH-a) reduce estrogen to postmenopausal levels by inhibiting gonadotropin secretion, thereby alleviating symptoms and inhibiting fibroid growth and atrophy. However, fibroids will return to their original size sooner after discontinuation. Side effects such as perimenopausal syndrome and osteoporosis may occur after medication, so it is recommended that the medication should not exceed 6 months. Application indications: reduction of fibroids in favor of pregnancy; preoperative treatment to control symptoms and correct anemia; application of fibroids before surgery to reduce the difficulty of surgery or make vaginal surgery possible; for women near menopause, Transition to natural menopause early and avoid surgery.

(2) Mifepristone (RU486) can be used as a preoperative medicine for uterine fibroids. It can be used for anemia patients with uterine fibroids to suppress menstruation, reduce the volume of fibroids, and reduce the possibility of blood transfusion. Because it can cause endometrial hyperplasia, long-term use is not recommended.

3. Surgical treatment

Surgery remains the most commonly used treatment for uterine fibroids. Mainly divided into hysterectomy and fibroid removal.

(1) Indications for surgery After multiple secondary anemia, drug treatment is not effective; Severe abdominal pain, sexual intercourse pain or chronic abdominal pain, acute abdominal pain caused by torsion of pedicled fibroids; symptoms of bladder and rectal compression; can determine muscle Tumors are the only cause of infertility or repeated miscarriages; fibroids grow faster and suspect malignant changes. Due to the presence of fibroids, the uterus is more than 10 weeks pregnant. Surgery can be performed abdominally, transvaginally, or under hysteroscopy and laparoscopy.

(2) Surgery method Hysterectomy has surgical indications, and it is not required to retain fertility or suspect malignant changes. Hysterectomy is feasible. Since the cervix may become cancerous in the future after subtotal hysterectomy and the management of stump cancer is very difficult, it is currently recommended for most patients. Cervical smear cytology should be performed before surgery to exclude cervical malignant lesions. Non-menopausal women can retain double attachments, and consider removing both attachments at the same time after menopause.

Surgery can be performed abdominally, laparoscopically, or transvaginally, depending on the size of the patient's uterus, the location of the fibroids, the presence of pelvic and abdominal adhesions, abdominal and vaginal conditions (such as excessive obesity, etc.), and the technical specifications of the doctor's and hospital's equipment. set. Myomectomy For patients who are 40 years old and wish to retain fertility, or patients who do not want to remove the uterus without fertility requirements, consider myomectomy. The size, location and number of fibroids should be fully understood by vaginal examination and B-ultrasound before surgery, so as to choose the appropriate method (opening, laparoscopy, hysteroscopy or vaginal) for fibroid removal. Laparoscopic trauma is small and the patient recovers quickly. It is the most popular minimally invasive surgical method. However, laparoscopy has high technical requirements for doctors, and because laparoscopy has no tactile sensation, it is generally only suitable for removing single or fewer fibroids under the serosal membrane or between the muscular walls. At present, there is no unified opinion on this. It is generally recommended that a single fibroid should not be too large, and the number should not be too large. Hysteroscopic surgery is suitable for submucosal fibroids, but for type 2 submucosal fibroids that protrude into the uterine cavity, only a small proportion of fibroids may not be removed at once. Open fibroids have a wide range of indications. For fibroids, multiple fibroids, oversized uterus, and those who relapse after removal, they should be removed first. With the help of the operator's sense of touch, all fibroid nodules that are touched in the uterus can be eliminated as much as possible, which is more suitable for young people with fertility requirements.

The postoperative recurrence rate is 20% to 30%. The causes of recurrence may be: small fibroids not found during surgery, which gradually increase under the action of sex hormones; or the patient itself has the pathogenesis of fibroids, which is constantly New fibroids occur.

references:

1. Cao Zeyi, editor. Chinese Gynecologic Oncology. People's Military Medical Press. 2011 1st edition: 1018-1032.

2. Le Jie, chief editor. Obstetrics and Gynecology. People's Medical Publishing House, 2011 7th edition: 269-271.