Authors : Aulia Rahman, S. Ked Endang Sri Wahyuni, S. Ked Nova Faradilla, S. Ked Faculty of Medicine University of Riau Pekanbaru, Riau 2009 Files of DrsMed FK UR (http://www.files-of-drsmed.tk 0
INTTRODUCTION Leiomyomas (also called myomas or fibroids) are benign tumors of the uterus and are composed mainly of smooth muscle with some fibrous connective tissue elements. Myomas are the most common pelvic tumors and one third of the hysterectomies performed annually are for fibroids. Approximately 20% to 25% of women older than 35 years have a uterine myoma. Myomas are usually asymptomatic, more common in black women than in white women, rare before puberty, and usually shrink after menopause. They are estrogen-dependent and may grow during estrogen replacement therapy (periand postmenopausal) or during pregnancy. They are single or, more commonly, multiple tumors in the uterine corpus (i.e., intramural, subserosal, or submucosal). They can be pedunculated and, on occasion, involve the cervix, round ligament, or broad ligament. 1 1
LITERATURE DEFINITION Myomas are benign tumors derived from the smooth muscle cells of the myometrium. They are the most common neoplasm of the uterus. but most are asymptomatic. However, myomas can cause excessive uterine bleeding, pelvic pressure and pain, as well as infertility. 2 EPIDEMIOLOGY Estimates are that more than 45% of women have myomas by the fifth decade of life. They are the primary indication for 200,000 to 300,000 hysterectomies in the United States each year. Although myomas have the potential to grow to impressive sizes, their malignant potential is minimal. Sarcomatous changes occur in less than 1 per 1000 uteri with fibroids. 2 RISK FACTOR Risk factors for developing myomas include increasing age during the reproductive years, ethnicity (African-American women have at least a 2- to 3-fold increased risk compared to Caucasian women), nulliparity, and family history. The data are suggestive that higher body mass index is associated with a greater risk of myomata. Oral contraceptive pills and depot medroxyprogesterone acetate (DMPA) injections may be associated with reduced risk. 2 PATHOGENESIS Factors that initiate myomas are not known, but ovarian sex steroids are important for their growth. myomas rarely develop before menarche and seldom develop or enlarge after menopause, unless stimulated by exogenous hormones. Myomas can also enlarge dramatically ding pregnancy. Myomas have increased levels of estrogen and progesterone receptors compared to other smooth muscle cells. Estrogen stimulates the proliferation of smooth muscle cell, whereas provgesterone increases the production of 2
proteins that interfere with programmed cell death (or apoptosis). Myomas also have higher levels of growth factors that stimulate the production of fibronectin and collagen, major components of the extracellular matrix that characterizes these lesions. 2 CLASSIFICATION Myomas are classed into subgroups by their relative anatomic relationship and position to the layers of the uterus. The three most common types of myomas are intramural, subserous, and submucous, with special nomenclature for broad ligament and parasitic myomas. Continued growth in one direction determines which myomas will be located just below the endometrium (submucosal) and which will be found just beneath the serosa (subserosal). Although only 5% to 10% of myomas become submucosal, they usually are the most troublesome clinically. These submucosal tumors may be associated with abnormal vaginal bleeding or distortion of the uterine cavity that may produce infertility or abortion. Rarely, a submucosal myoma enlarges and becomes pedunculated. The uterus will try to expel it, and the prolapsed myoma may protrude through the external cervical os. 3 Subserosal myomas give the uterus its knobby contour during pelvic examination. Further growth of a subserosal myoma may lead to a pedunculated myoma wandering into the peritoneal cavity. This myoma may outgrow its uterine blood supply and obtain a secondary blood supply from another organ, such as the omentum, and become a parasitic myoma. Growth of a myoma in a lateral direction from the uterus may result in a broad ligament myoma. The clinical significance of broad ligament myomas is that they are difficult to differentiate on pelvic examination from a solid ovarian tumor. Large, broad ligament myomas may produce a hydroureter as they enlarge. 3 CLINICAL FINDING Uterine fibroids are frequently diagnosed on the basis of clinical findings of an enlarged, irregular uterus on pelvic examination. They are also frequently noted on ultrasonography obtained for a variety of indications and may be an incidental finding. However, any pelvic tumor potentially can be confused with an enlarged uterus. 4 3
A. History 1 1. Abnormal bleeding is the most common symptom associated with myomas. Initially, there may be an increase only in menstrual flow. However, patients may have any type of abnormal bleeding, including continuous bleeding and severe hemorrhage. Other sources of abnormal bleeding should also be considered in the work-up of myomas. Fibroids will usually cause menorrhagia rather than metrorrhagia. 2. Pain is not characteristic of myomas, although it can be present in up to one third of patients. a. It generally occurs with the menstrual cycle and may be caused by a submucous or pedunculated myoma stimulating uterine contractions. b. Acute pain with myomas is associated with torsion of a pedunculated myoma or degeneration of a large myoma. 3. As myomas enlarge, they may cause a feeling of pelvic heaviness or produce pressure symptoms by compressing nearby organs. a. Constipation may occur as well as decreased bladder capacity or urinary retention. b. Occasionally, there may be compression of one or both ureters. 4. Infertility may be a presenting complaint with myomas. Although large myomas are compatible with pregnancy, they may on occasion be a factor in infertility, according to one large study. When myomas are the presumed cause of infertility, 17% of patients become pregnant after myomectomy. Preconception counseling regarding fibroids should address an 18% risk of spontaneous abortion, a 15% risk of painful myomas, 20% to 30% preterm labor rate, and the risk of malpresentations and malformations. B. Physical examination. On bimanual examination, the uterus is distorted by one or more smooth, spherical, firm masses. The uterine size is estimated in weeks, corresponding to the pregnant uterus of the same size. It is often not obvious whether the pelvic mass is of uterine origin. 1 4
C. Laboratorium Anemiais the most common laboratory finding with uterine myomas (as a result of abnormal uterine bleeding and infection). Leukocytosis as well as elevated ESR may occur if myomas are complicated by endometritis or carneous or septic degeneration. 5 MANAGEMENT Management of myomas depends on the patient's symptoms, age, parity, desire for future pregnancies, and the size of the myomatous uterus. 1 1. Surgical intervention has been recommended routinely when a uterus reaches a 12- to 14-week size, although no prospective studies have established the degree of risk for not intervening. Size alone is not an adequate indication for treatment. a. Normally, the treatment would be a hysterectomy. b. Myomectomy may be done to preserve fertility by performing laparoscopy, hysteroscopy, or exploratory laparotomy. The 10-year recurrence risk is 27%. 2. Myomas are removed when they cause pain, abnormal bleeding that is uncontrolled by hormone management, pressure, compromise to pelvic organs, or a rapid change in size. a. Hysterectomy is the procedure of choice if fertility is not a consideration. b. For infertility with no other origin, myomectomy may improve fertility. c. If bleeding is the only symptom and uterine pathology has been ruled out, endometrial ablation with fibroid resection may be indicated. 3. Asymptomatic myomas may be followed by annual examinations. a. After menopause, the myomas usually shrink and they should never grow. b. Rapid growth, or any growth after menopause, is cause for hysterectomy to rule out sarcoma. c. Estrogens should be used cautiously before and after the menopause since they may cause myomas to grow. d. Medical therapy can be used to control bleeding or to shrink fibroids. Progestins, such as medroxyprogesterone acetate (Provera), 10 mg PO for 5
10 to 13 days each month, can control excessive bleeding and are useful especially for perimenopausal women. The GnRH analogues induce pseudomenopause, resulting in decreased tumor volume. Although their use in long-term management is limited, presurgical treatment and temporary symptomatic relief prove useful. Most studies have shown that myomas return to their previous size within 6 months of treatment. In a study of perimenopausal women treated for 6 months with GnRH agonists, about 30% did not experience a regrowth of fibroids. e. Radiologic uterine artery embolization is becoming an alternative to hysterectomy in the treatment of fibroids. Reports have shown up to a 60% reduction in uterine volume within 2 to 4 months of treatment. Presently, the procedure is not recommended for women who desire future fertility. DIFFERENTIAL DIAGNOSIS The uterine enlargement or irregularity caused by a myoma also may be caused by pregnancy, adenomyosis, leiomyosarcoma, or solid ovarian neoplasms. On imaging studies myomas may be confused with focal myometrial contraction. Other conditions to be considered include subinvolution, congenital anomalies, adherent adnexa, omentum or bowel benign hypertrophy, and sarcoma or carcinoma. Finally, there is a very rare variant of myoma, benign metastasizing myoma. The condition is characterized by multiple smooth muscle nodules, primarily located in the lung. 5 6
REFFERENCES 1. Jeanne A. Conry. The Enlarged Uterus. In: Manual of Outpatient Gynecology. Editors: Havens, Carol S.; Sullivan, Nancy D. 4th Edition. 2002. Lippincott Williams & Wilkins. Chapter 13. 2. George Moore & Anita L. Nelson. Uterine Leiomyomas. In: Essentials of Obstetrics and Gynecology. Fourth Edition. Editor: Hacker, et al. Elsevier.Ltd. 2007. P. 269-273 3. Cunningham, et al. Abnormalities of the Reproductive Tract. In: Williams Obstetrics. 22th Edition. McGraw-Hill Companies. 2007. Chapter 40 4. Paula J. Hillard Adams. Benign Diseases of the Female Reproductive Tract. In: Novak's Gynecology:, Editors: Jonathan S. Berek. 2002.Lippincott Williams & Wilkins. Page 469 5. Martin L. Pernoll, Benson & Pernoll s Handbook of Obstetrics & Gynecology 10th Edition. Mc Graw Hil. 2001. New York. Page 619-625 Files of DrsMed FK UR (http://www.files-of-drsmed.tk 7