UTERINE MYOMAS

UTERINE MYOMAS - Eric L. Jenison, MD; Michael P. Hopkins, MD, MEd; Summer L. James, MD
BASICS
DESCRIPTION
• Uterine leiomyomas are well-circumscribed, pseudo-encapsulated benign tumors composed mainly of smooth muscle but with varying amounts of fibrous connective tissue.
• 3 major types
- Submucous: ~5% of all cases, evincing abnormal uterine bleeding and infection, and do occasionally protrude from cervix
- Subserous: Common; may become pedunculated and rarely parasitic
- Intramural: Common; may cause marked uterine enlargement
• System(s) Affected: Reproductive
• Synonym(s): Fibroids; Myoma; Fibromyoma; Myofibroma; Fibroleiomyoma
ALERT
Geriatric Considerations
In postmenopausal patients with newly diagnosed uterine myoma or enlarging uterine myomas, high suspicion of uterine sarcoma or other gynecologic malignancy
Pregnancy Considerations
• Pregnant women may need additional fetal testing if placenta is located over or near a fibroid.
• Complications during pregnancy include abortion, premature labor, 2nd-trimester rapid myoma growth leading to degeneration and pain, and 3rd-trimester fetal malpresentation and dystocia during labor and delivery.
• Previous myomectomy patients may develop uterine rupture during labor. Caesarean section is recommended if endometrial cavity has been entered during myomectomy.
GENERAL PREVENTION
Excessive growth may occur with estrogen stimulation (i.e., estrogen-containing birth control, HRT, and pregnancy).
EPIDEMIOLOGY
• Predominant age: 4th and 5th decades
• Predominant sex: Female only
Incidence
• Incidence increases with each decade during reproductive years and is highest in perimenopausal age group.
• Not seen in premenarchal females.
Prevalence
• 4-11% of all women
• 20% of all women 35 years of age
• 40% of women 50 years of age
RISK FACTORS
• Later reproductive and perimenopausal age groups
• 3-9 times higher among African Americans
ETIOLOGY
• May arise from totipotential cells that normally give rise to muscle and connective tissue cells
• May arise from small immature smooth muscle cell nests
• Positive correlation with estrogen stimulation (i.e., not seen before menarche), may grow rapidly during pregnancy, with use of oral estrogen, and with estrogen-producing tumors
• Myomas usually regress after pregnancy and menopause.
ASSOCIATED CONDITIONS
Endometrial carcinoma is also associated with high unopposed estrogen stimulation.


DIAGNOSIS
SIGNS AND SYMPTOMS
• Most affected patients: Asymptomatic disease only becomes suspected based on results of pelvic examination.
• Most common symptom is abnormal uterine bleeding. Hypermenorrhea is most common. Symptoms of secondary anemia may result.
• Pressure on bladder may result in suprapubic discomfort, urinary frequency.
• Pressure on rectosigmoid may result in low back pain.
• Edema and varicosities of the lower extremities may result from large tumors.
• Pain may result from twisted, pedunculated myomas or degenerating, hemorrhagic, or infected myomas.
• Infertility may result from submucous myomas or with distortion of uterine cavity.
• Rapid growth, particularly in perimenopausal or postmenopausal patients, may indicate sarcoma.
Physical Exam
Presumptive diagnosis by abdominal and pelvic examination: Firm, smooth nodules or masses arising from uterus. Masses are mobile without pain.
TESTS
Lab
• Pregnancy test
• CBC with differential
Imaging
• Ultrasonography shows characteristic hypoechoic appearance.
• Saline-infusion hysterosonography may help to distinguish submucosal myomas.
• Hysterosalpingogram to evaluate contour of endometrial cavity
• CT scan, MRI may help to differentiate complex cases or used when uterine artery embolization is planned.
• IV pyelogram
• Barium enema
Diagnostic Procedures/Surgery
• Fractional dilation and curettage aids in ruling out cervical or uterine carcinomas.
• Hysteroscopy may help diagnose submucous myomas.
• Laparoscopy may be useful in complex cases and to rule out other pelvic disease or disorder.
Pathological Findings
• Myomas are usually multiple and vary in size and location; have been reported up to 100 lb.
• Gross pathology reveals firm tumors with characteristic whorl-like trabeculated appearance. A thin pseudo-capsular layer is present.
• Microscopic appearance reveals bundles of smooth muscle mixed with varying amounts of connective tissue elements running in different directions.
• Cellular variant has a preponderance of muscle cells. Mitoses are rare.
• May undergo various types of degeneration
- I. Hyaline degeneration: Very common
- II. Calcification: Late result of circulatory impairment to myomas
- III. Infection and suppuration: Most common with submucosal myomas
- IV. Necrosis: Most common with pedunculated myomas secondary to torsion
- V. Sarcomatous change: Incidence 1.0-0.1% of clinically apparent myomas
DIFFERENTIAL DIAGNOSIS
• Intrauterine pregnancy
• Ovarian tumor
• Cecal or sigmoid tumor
• Appendiceal abscess
• Diverticulitis
• Pelvic kidney
• Urachal cyst
TREATMENT
STABILIZATION
Outpatient usually; inpatient for some surgical procedures
GENERAL MEASURES
• Treatment must be individualized.
• Patients with minimal symptoms may be managed with iron preparations and analgesics.
• Conservative management: Asymptomatic myomas should be closely observed with pelvic examinations and ultrasonography at 3-6-month intervals, as long as size remains stable. Usually regression occurs after menopause.
• Patients that do not want surgery or pharmacologic therapy may consider uterine artery embolization (UAE).
• UAE averages 30-46% shrinkage of myomas (1); painful, may cause ovarian failure or amenorrhea
Diet
No restrictions
Activity
• After hysteroscopic or laparoscopic myomectomy, bed rest for 24 hours, no sexual intercourse for 2 weeks
• After laparotomy for myomectomy or hysterectomy, 3-5 days inpatient, followed by limited activity and no sexual intercourse for 1 month
MEDICATION (DRUGS)
Patients with minimal symptoms may be managed conservatively with iron preparations for anemia and analgesics.
First Line
• Progestins such as norethindrone, 10 mg/d, or medroxyprogesterone (Depo-Provera) 200 mg IM, once monthly, may reduce overall uterine size. (2)
- Contraindications: History of thromboembolic events; see the manufacturer's profile
- Adverse reactions: See the manufacturer's profile.
- Significant interactions: See the manufacturer's profile.
• Luteinizing hormone-releasing hormone (LHRH) agonists such as nafarelin (Synarel Nasal Spray), goserelin (Zoladex Depot), and leuprolide (Lupron Depot)
- Induce abrupt, artificial menopause and render patients asymptomatic.
- Induce atrophy of myomas by up to 40% within 2-3 months (2)
- May be valuable as a preoperative adjunct to myomectomy or hysterectomy by allowing recovery of anemia, donation of autologous blood, and possibly converting abdominal to vaginal hysterectomy, thereby decreasing postoperative pain, hospitalization, and morbidity (2)
- Not recommended for use >6 months because of osteoporosis risk
- Following discontinuation, myomas return within 60 days to pretherapy size
• Contraindications: Osteoporosis; refer to the manufacturer's profile
• Adverse reactions: Acute menopausal symptoms, decreased bone density; refer to manufacturer's profile
• Significant interactions: Refer to the manufacturer's profile.
SURGERY
• Surgical management is indicated in the following situations (2)[B]
- Excessive uterine size or excessive rate of growth (except during pregnancy)
- Submucosal location if associated with hypermenorrhea
- Pedunculated myomas may undergo torsion, pain, necrosis, and hemorrhage.
- Symptomatic from pressure on bladder or rectum
- If differentiation from ovarian mass is not possible
- If associated pelvic disease present (i.e., endometriosis, pelvic inflammatory disease)
- If infertility or habitual abortion is likely due to the anatomic location of the myoma
• Surgical procedures
- Hysteroscopic or laparoscopic cautery or laser myoma resection can be performed in selected cases.
- Endometrial ablation for small submucosal myomas
- Endometrial sampling should be performed prior to or in conjunction with procedure.
- Abdominal or laparoscopic myomectomies may be performed in younger women who want to maintain fertility. (2)[B]
- Hysterectomy, either vaginal or abdominal, is procedure of choice for symptomatic women who do not want to maintain fertility. (2)[B]
- Preliminary pap smear and endometrial biopsy should be performed to rule out malignant or premalignant conditions. (3)[B]
FOLLOW-UP
PROGNOSIS
• After abdominal myomectomy, 57% pregnancy rate in previously infertile patients (3)
• At least 10% of myomas recur after myomectomy.
COMPLICATIONS
• May mask other gynecologic malignancies (e.g., uterine sarcoma, ovarian cancer)
• Degenerating fibroid may cause pain.
- May rarely prolapse through the cervix
PATIENT MONITORING
• Newly diagnosed uterine myoma, if symptomatic or of excessive size: Every 2-3 months with pelvic exam and ultrasonography
• Monitor hemoglobin and hematocrit levels, if uterine bleeding is excessive.
• If uterine size and symptoms are stable, monitor only every 6-12 months.
REFERENCES
1. Gupta JK, Sinha AS, Lumsden MA, Hickey M. Uterine artery embolization for symptomatic uterine fibroids. Cochrane Database Syst Rev. 2006;1.
2. Wallach EE, Vlahos NF. Uterine myomas: An overview of development, clinical features and management. Obstet Gynecol. 2004;104(2):393-406.
3. Lefebvre G, et al. The management of uterine leiomyomas. J Obstet Gynaecol Can. 2003;25(5):396-418.