• Main clinical features include:
    • Chronic pelvic pain (found in 70-80% of patients)
    • Dyspareunia (suggests deep posterior infiltration)
    • Infertility (21% prevalence rate)
  • Other symptoms may include severe dysmenorrhea, pain on ovulation, noncyclical pelvic pain, cyclical bowel or bladder symptoms w/ or w/o abnormal bleeding or pain, chronic fatigue, or dyschezia
    • In adolescents, endometriosis is the most common cause of secondary dysmenorrhea
  • Although it is vital to consider the patient's complaints affecting physical, mental & social well-being, it should be noted that patients w/ endometriosis may be completely asymptomatic (w/ 2-22% prevalence rate)


Patient’s History

  • Should include:
    • Age (reproductive year, most commonly at 25-29 yr old)
    • In utero exposure to environmental toxins like diethylstilbestrol which increases the incidence of endometriosis
    • Family history of endometriosis (7x higher risk than w/ no family history)

Physical Exam

  • Ideally done during early menses because endometrial implants are likely to be largest & deep infiltrating, hence more easily detectable
  • Diagnosis is more definite if deeply infiltrative nodules are found on the uterosacral ligaments or in pouch of Douglas, &/or lesions are directly seen in the vagina or cervix
  • Note that there may be no abnormal findings on physical exam
  • For patients who are not sexually active, a rectal-abdominal exam may be better tolerated than a vag-abdominal exam
  • A cotton swab can be inserted into the vagina to document patency & exclude complete or partially obstructive anomalies such as a transverse vaginal septum, imperforate or microperforate hymen, or an obstructed hemivagina

Other frequent findings:

  • Pain w/ uterine movement or pelvic tenderness
  • Tender, enlarged adnexal masses
  • Fixation of adnexa or uterus in a retroverted position

Laboratory Tests

  • Urinalysis & urine culture to identify pain originating in the urinary tract (eg cystitis, stones)
  • Pregnancy test & tests for sexually transmitted infection (STI) like gonorrhea, chlamydia, when appropriate


  • Gold standard for diagnosis, unless lesions are visible in the vagina
    • May also be used for therapeutic purposes
    • Should not be done during or w/in 3 mth of hormonal treatment to avoid under-diagnosis
  • Biopsy & histopathologic study of at least one lesion is ideal
    • 3 cardinal features (ie ectopic endometrial glands, ectopic endometrial stroma, & hemorrhage into adjacent tissue) should be present
    • In adolescents, features of endometriosis may be atypical (ie clear vesicles & red lesions)
  • A negative laparoscopy does not exclude the diagnosis of endometriosis
  • Depending on the severity of the disease found, it is best to remove the endometriotic lesion at the same time
  • Differential diagnoses (eg endosalpingiosis, mesothelial hyperplasia, hemosiderin deposition, hemangiomas, adrenal rests, inflammatory changes, splenosis & reactions to oil-based radiographic dyes) can be excluded by biopsy

Laparoscopic Classification (based on location, extent & severity of lesions)

  • Stages based on American Fertility Society (AFS)
    • Minimal disease (stage I) - characterized by isolated implants & no significant adhesions
    • Mild endometriosis (stage II) - consists of superficial implants <5 cm in aggregate, scattered on the peritoneum & ovaries; with no significant adhesions
    • Moderate disease (stage III) - exhibits multiple implants, both superficial & invasive; peritubal & periovarian adhesion may be evident
    • Severe disease (stage IV) - characterized by multiple superficial & deep implants, including large ovarian endometriomas; filmy & dense adhesions are usually present
  • Severity of symptoms does not match w/ the above stages

Imaging Studies

Transvaginal Sonography (TVS)
  • Considered the 1st-line imaging tool to examine suspected endometriosis
  • Should be performed to determine whether a pelvic mass or structural anomaly is present
  • Useful in diagnosing or excluding rectal endometriosis
  • May identify an ovarian endometrioma & help identify other structural causes of pelvic pain, such as ovarian cysts, torsion, tumors, genital tract anomalies & appendicitis
    • Distinguishes endometrioma from other ovarian cysts w/ 83% sensitivity & 89% specificity
    • Ovarian endometrioma may be diagnosed in premenopausal women w/ findings of ground glass echogenicity & 1-4 compartments & absence of papillary structures w/ blood flow

Magnetic Resonance Imaging (MRI)

  • May be helpful in some cases to better define an abnormality suspected by sonography
    • Detects ovarian endometrial cysts w/ 90% sensitivity & 98% specificity
  • Provides exact location of deep retroperitoneal lesion
  • May be used as part of pre-op workup, but should not be used as 1st-line

Miscellaneous Tests

Serum CA-125

  • Women w/ endometriosis may have high serum CA-125 concentration
    • No value as diagnostic tool in endometriosis
    • Also elevated in ovarian epithelial neoplasia, myoma, adenomyosis, acute PID, ovarian cyst, pregnancy


  • May be considered in suspected endometriosis lesions & endometriomas to help confirm the diagnosis & exclude possible malignancy
    • In patients w/ endometriosis, prevalence of ovarian cancer is <1%