Essentials of Diagnosis
- Pelvic pain related to menstrual cycle.
- Increased frequency among infertile women.
Endometriosis is an aberrant growth of endometrium outside the uterus, particularly in the dependent parts of the pelvis and in the ovaries and is a common cause of abnormal bleeding and secondary dysmenorrhea. Its causes, pathogenesis, and natural course are poorly understood. The prevalence in the United States is 2% among fertile women and three- to fourfold greater than that in the infertile.
Depending on the location and extent of the endometrial implants, infertility, dyspareunia, or rectal pain with bleeding may result. Aching pain tends to be constant, beginning 2-7 days before the onset of menses, and becomes increasingly severe until flow slackens. Pelvic examination may disclose tender indurated nodules in the cul-de-sac, especially if the examination is done at the onset of menstruation.
Endometriosis must be distinguished from pelvic inflammatory disease, ovarian neoplasms, and uterine myomas. With salpingitis and endometriosis, the symptoms are aggravated by menstruation. Bowel invasion by endometrial tissue may produce blood in the stool that must be distinguished from bowel neoplasm. Differentiation in these instances depends upon proctosigmoidoscopy and biopsy.
Imaging is of limited value. Ultrasound examination will often reveal complex fluid-filled masses that cannot be distinguished from neoplasms. MRI is more sensitive and specific than ultrasound, particularly in the diagnosis of adnexal masses. However, the clinical diagnosis of endometriosis is presumptive and usually confirmed by laparoscopy.
A. Medical Treatment
Medical treatment, using a variety of hormonal therapies, is effective in the amelioration of pain associated with endometriosis. However, there is no evidence that any of these agents increase the likelihood of pregnancy. Their preoperative use is of questionable value in reducing the difficulty of surgery. Most of these regimens are designed to inhibit ovulation over 4-9 months and lower hormone levels, thus preventing cyclic stimulation of endometriotic implants and decreasing their size. The optimum duration of therapy is not clear, and the relative merits in terms of side effects and long-term risks and benefits show insignificant differences when compared with each other and, in mild cases, with placebo.
1. The GnRH analogs such as nafarelin nasal spray, 0.2-0.4 mg twice daily, or long-acting injectable leuprolide acetate, 3.75 mg intramuscularly monthly, used for 6 months, suppress ovulation. Side effects of vasomotor symptoms and bone demineralization may be relieved by “add-back” therapy with norethindrone, 5-10 mg daily.
2. Danazol is used for 6-9 months in the lowest dose necessary to suppress menstruation, usually 200-400 mg twice daily. Side effects are androgenic and include decreased breast size, weight gain, acne, and hirsutism.
3. Any of the combination oral contraceptives may be given, one daily, without interruption, for 6-12 months. Breakthrough bleeding can be treated with conjugated estrogens, 1.25 mg daily for 1 week, or estradiol, 2 mg daily for 1 week.
4. Medroxyprogesterone acetate, 100 mg intramuscularly every 2 weeks for four doses and then 100 mg every 4 weeks; add oral estrogen or estradiol valerate, 30 mg intramuscularly, for breakthrough bleeding. Use for 6-9 months.
5. Low-dose oral contraceptives can also be given cyclically; prolonged suppression of ovulation will often inhibit further stimulation of residual endometriosis, especially if taken after one of the therapies mentioned above.
6. Analgesics, with or without codeine, may be needed during menses. Nonsteroidal anti-inflammatory drugs may be helpful.
B. Surgical Measures
Surgical treatment of endometriosis - particularly extensive disease - is effective both in reducing pain and in promoting fertility. Laparoscopic ablation of endometrial implants along with uterine nerve ablation significantly reduces pain. Ablation of implants and, if necessary, removal of ovarian endometriomas enhance fertility, though subsequent pregnancy rates are related to the severity of disease. Women with disabling pain who no longer desire childbearing can be treated definitively with total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH-BSO).
The prognosis for reproductive function in early or moderately advanced endometriosis is good with conservative therapy. TAH-BSO is curative for patients with severe and extensive endometriosis with pain.
Farquhar C: Endometriosis. Clin Evid 2002;7:1654.
Murphy AA: Clinical aspects of endometriosis. Ann N Y Acad Sci 2002;955:1.
Olive DL et al: Treatment of endometriosis. N Engl J Med 2001; 345:266.
Revision date: June 18, 2011
Last revised: by Janet A. Staessen, MD, PhD