Endometriosis

Introduction

Essentials of Diagnosis

• Pelvic pain related to menstrual cycle.
• Dysmenorrhea.
• Dyspareunia.
• Increased frequency among infertile women.

General Considerations

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.

Clinical Findings

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.

Treatment

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.