Gynecology: Endometriosis

Guest · **posting in usmle forum about Obstetrics & Gynecology**

1. Definition. Endometriosis is the presence of functioning endometrial tissue outside its normal location, most frequently on the ovaries, uterosacral ligaments, cul-de-sac, and occasionally uterovesical peritoneum. However, it may occur elsewhere including nasal mucosa, lung or even brain. It is estrogen-dependent and generally regresses after menopause or oophorectomy.

2. Pathogenesis. Several factors may play a role including retrograde transport and implantation, metaplastic transformation of "coelomic" peritoneum, lymphatic or hematogenous dissemination, immunological defects, genetic predisposition.

3. Evaluation
1. History.
1. The most common symptoms associated with pelvic endometriosis are dysmenorrhea (66%), deep dyspareunia (33%), infertility (60%), and low back pain or chronic pelvic pain that worsens with menses. May have premenstrual spotting and menorrhagia. Dysmenorrhea often precedes menses and lasts throughout the period.
2. Less common symptoms include dyschezia (painful defecation), diarrhea, intermittent constipation, cyclic abdominal pain, dysuria, urinary frequency and hematuria.
3. One-third of women with endometriosis are asymptomatic and even extensive disease may be asymptomatic.

2. Physical examination.
1. Fifty percent of women have a normal clinical examination.
2. Findings will be accentuated in early menses and may include a fixed, tender, retroverted uterus; tender nodules along the uterosacral ligaments (with obliteration of the cul-de-sac); nodules on the back of the uterus and cervix; unilateral or bilateral fixed asymmetric adnexal masses. Rectovaginal exam is important to assess the posterior uterus and cul-de-sac.
3. Up to 10% of teens with endometriosis have congenital outflow tract obstruction.

3. Diagnostic aids:
1. Laparoscopy should be done to confirm the diagnosis if treatment will be more extensive than under "mild disease" below since the clinical diagnosis may be wrong 30% to 40% of the time. Laparos-copy will help assess the extent and stage of the disease as well as tubal patency. Patient-assisted laparoscopy can improve the diagnostic yield.
2. Ultrasound may be helpful with a large pelvic mass, but cannot visualize small implants or differentiate types of cystic lesions.

4. Management: Medical treatment of endometriosis cannot restore fertility (see section on Infertility), but may help with pain or dyspareunia. Pain recurs after treatment in 53%.
1. Mild disease. Usually the diagnosis will be suspected but not confirmed, since laparoscopy is usually not indicated. Treatment can include observation and NSAIDS. Additional treatment includes:
1. Combination oral contraceptives, given for at least 6 months. Response rate is 75%.
2. Depo-Provera 150 mg IM Q3 months. Return to fertility may be delayed after discontinuation.
2. Treatment options in moderate disease. Diagnosis should be confirmed by laparoscopy prior to initiating therapy.
1. "Pseudomenopause." Danazol is a synthetic androgen that suppresses gonadotropins and causes amenorrhea. Side effects include vasomotor symptoms such as atrophic vaginitis, weight gain, fluid retention, migraines, dizziness, fatigue, depression, decreased HDL, acne, hirsutism, and potentially irreversible voice changes. Danazol 200 or 400 mg PO BID for up to 6 months. Begin on the first day of menstruation. Use a barrier contraceptive the first month: female fetuses may be adversely affected. Response rate is 84%-92%.
2. "Pseudopregnancy." Continuous oral contraceptives: use a standard monophasic formulation. Side effects as per OCP. Have the patient take one active pill every day continuously, beginning on the third day of menstruation. When breakthrough bleeding occurs, increase to two pills daily for 5 days, then return to a single pill daily. If necessary, may use up to 3-4 pills daily, although nausea may limit therapy. Maintain amenorrhea for 6-9 months: 80% of patients will experience improvement of symptoms.
3. Progestin therapy is useful if pseudopregnancy is not tolerated or is contraindicated. Side effects include breakthrough bleeding, depression, irritability, lipid changes. Initiate therapy during menses. Progestins appear to be as effective as other treatments.
1. Depo-Provera 150 mg IM Q3 months, may increase to 200 mg IM Q month x 4 months if needed to produce prolonged amenorrhea. Return to fertility may be delayed after discontinuation.
2. Medroxyprogesterone 10-30 mg PO QD is an alternative.
4. Conservative surgery to laparoscopically remove extrauterine endometrial tissue is often performed at the time of laparoscopic diagnosis. May also use pharmacotherapy from 6 weeks before to 3-6 months after surgery. Recurrence rate is 19% over 5 years.
3. Severe disease.
1. Definitive surgery. Hysterectomy and bilateral oophorectomy. Recurrence rate is 10% over 10 years.
2. GnRH agonists such as leuprolide acetate (IM), goserelin (SQ implant) or nafarelin (nasal spray) induce an artificial menopausal state. Side effects are similar to menopause, including decreased bone mineral density. Response rate is 90%.