Cause: Ectopic uterine mucosa, unclear why; various theories include embryonic residua, transtubal transport of endometrial fragments and implantation, coelomic metaplasia, "retrograde menstruation," and lymphatic, surgical, or vascular metastases?
Pathophys:Ectopic foci of functioning endometrium cause pain when bleed into confined, nonuterine areas. Commonly on ovaries but also beneath peritoneum of bladder, tubes, bowel, pelvic scars postop. Can result in tubal or ovarian sterility. Sx severity correlates poorly with anatomic findings
Sx:Acquired premenstrual or menstrual pain, dyspareunia, pain on defecation; sterility; but often asx
Si:Tenderness on pelvic exam; retroverted fixed uterus; pelvic mass
Lab:Endo:Laparoscopy, usually diagnostic, shows hemorrhagic spots or cysts, often scarred
Xray:
Ultrasound may show irregular pelvic mass; but is a poor test except to r/o other causes of pelvic pain; frequent false negatives
MRI is 90% sens/specif for endometriosis in women w pelvic pain
Rx:
(Nejm 2001;345:266)
NSAIDs for pain
Birth control pills, typically high-progesterone content; either cyclic or continuous
Danazol 200-800 mg po qd, a weak androgen; 200-mg pill costs $1 (Ann IM 1982;96:625); adverse effects: androgenic side effects
GnRH (gonadotropin-releasing hormone) analog, nafarelin 400 µgm nasal spray qd (Med Let 1990;32:81; Nejm 2008;359:1136) or leuprolide (Lupron) 3.75 mg im depot q 1 mo for up to 6-mo course; adverse effects: cost ($300+/mo), estrogen deficiency sx including bone loss, which can be prevented w qd sc PTH (Nejm 1994;331:1618)
Progesterone: medroxyprogresterone 20-100 mg po constantly × 6-12 mo or cyclic 20-d rx; Depo-Provera 150 mg im q3mo; levonorgestrel implant (Norplant) q 5 yr (Med Let 1991;33:17)
Surgical: laparoscopic electro- or laser cautery helps fertility in mild to moderate cases improve from 18% to 30% and is better than hormonal manipulation (Nejm 1997;337:217); TAH-BSO is 90% successful in relieving pain