Obstetrics and Gynecology/Endometriosis

Definition
Endometriosis is the ectopic location of endometrial tissue. This includes both stromal and glandular tissue. Endometriosis is known to occur at many varied sites.

Epidemiology

 * Endometriosis occurs in 7-12% of women.
 * Endometriosis occurs in up to 50% of premenopausal women.
 * Endometriosis occurs particularly in infertile women (~40%) and those with chronic pelvic pain (>70%).
 * Note that there has been no ethnic linking to endometriosis.

Etiology, Pathophysiology, and Risk Factors
The pathophysiology of endometriosis is not well understood. However, several theories exist:
 * Retrograde menstruation (NOTE: most endometriosis occurs in local pelvic sites accessible to retrograde menstruation)
 * Immunodeficiency (limiting the clearance of transplanted tissue)
 * Coelomic metaplasia (some factor induces the change of undifferentiated peritoneal cells into endometrial cells)
 * Lymphatic flow from uterus to ovaries
 * Hematogeneous spread to distant sites

Risk factors for endometriosis
 * Family history of endometriosis
 * Obesity (potential estrogen link)
 * Chronic pelvic pain
 * Infertility

Clinical Presentation and Diagnostic Approach

 * Many women with endometriosis are asymptomatic
 * The classical triad of symptoms, however, are
 * Dysmenorrhea (may be exaggerated or occurring before menses)
 * Dyspareunia
 * Infertility
 * The endometriosis patient will likely have suffered from chronic pelvic pain
 * Pain correlates well with the severity of lesions: this pain may extend well beyond the lesion sites
 * Systemic involvement: for example, cyclic diarrhea with menses.
 * Adenexal mass
 * Low-level echoes on ultrasound
 * Imaging should only be performed on the presence of an adenexal mass

The diagnosis of endometriosis is made via
 * Laparoscopy with biopsy and histology
 * Both glandular and stromal tissue must be found for diagnosis to be made

Management
Can be divided into Medical or Surgical management

Medical management of endometriosis

Non-Hormonal Hormonal
 * NSAIDs
 * BCP/MPA
 * DMPA
 * Danazol
 * GnRH analogues

Surgical management of endometriosis
 * Conservative: laparoscopic excision of lesions with restoration of normal anatomy, such as adhesiolysis, ablation of endometrial spot
 * Radical: hysterectomy with bilateral salpingo-oophorectomy, if Hormonal replacement therapy is required, progesterone should be given otherwise the estrogen dependent endometrioma may grow on pelvic tissue.