Workup for Endometriosis
Initial Clinical Assessment
The diagnosis of endometriosis is fundamentally clinical and does not require surgical confirmation before initiating empiric treatment. 1 Begin by identifying key symptom patterns and physical examination findings that strongly suggest endometriosis, as these alone can justify starting treatment.
Key Clinical Features to Document
- Pain patterns: Dysmenorrhea, dyspareunia (deep penetration pain), dyschezia (painful bowel movements), dysuria, or chronic pelvic pain 1, 2
- Infertility: Present in approximately 26-50% of patients with endometriosis 1, 2
- Physical examination findings: Nodularity in the posterior fornix, fixed retroverted uterus, tender uterosacral ligaments, or visible lesions on speculum examination 1, 3
Important caveat: Normal physical examination does not exclude endometriosis—superficial peritoneal disease is poorly detected by examination and imaging. 1, 2
Imaging Algorithm
Transvaginal ultrasound (TVUS) is the mandatory first-line imaging modality. 1 However, standard TVUS protocols are insufficient for deep endometriosis detection.
Imaging Protocol Selection
- Expanded protocol TVUS (with bowel preparation and systematic evaluation of deep compartments) demonstrates excellent performance for deep endometriosis, with sensitivity 82.5% and specificity 84.6% 1, 3
- Add transabdominal ultrasound to widen the field of view for urinary tract and bowel involvement beyond the pelvis 1
- MRI pelvis without IV contrast is equally appropriate as first-line imaging and is sufficient for detecting deep endometriosis 1
- MRI with IV contrast is highly recommended when differentiating endometriomas from ovarian malignancies 1
Critical pitfall: Do not rely on standard TVUS alone for deep endometriosis—expanded protocols or MRI are needed. 1 Standard protocols miss significant disease.
When to Use Advanced Imaging
- MRI should be obtained if TVUS is inconclusive, particularly when coexisting pathologies like leiomyomas are present (TVUS sensitivity drops to 33.3% in these cases) 1, 4
- CT pelvis has no role in standard endometriosis diagnosis and should not be ordered 1
Laboratory Testing
Pregnancy Test
- Check serum β-hCG to rule out pregnancy in all reproductive-age women with pelvic pain 5
Tumor Markers
- CA-125 has no clinical utility for diagnosis 6
- CA-125 may be helpful for monitoring clinical response in patients with confirmed extrauterine disease, but can be falsely elevated due to peritoneal inflammation/infection 6, 1
- Do not order CA-125 for diagnostic purposes 6
Hormonal Assessment
- Not routinely indicated for diagnosis 5
- Consider FSH, LH, and estradiol only if amenorrhea is present or ovarian function assessment is needed for other clinical reasons 5
What This Workup Accomplishes
This imaging-first approach serves multiple critical functions beyond diagnosis:
- Enables better surgical planning by mapping disease extent preoperatively 1
- Reduces surgical morbidity by preventing incomplete surgeries that require reoperation 1
- Identifies deep infiltrating disease that may require bowel or urologic surgery 6, 1
- Detects endometriomas that influence fertility management decisions 1
When Surgical Diagnosis Is Needed
Laparoscopy for definitive diagnosis is NOT required before starting empiric hormonal treatment. 1, 2 Surgery should be reserved for:
- Failure of first-line hormonal therapy 2
- Contraindications to hormonal therapy 2
- Suspected deep infiltrating disease requiring excision 6
- Fertility concerns where surgical treatment may improve outcomes 7
Important consideration: Diagnostic delay averages 5-12 years after symptom onset, with most women consulting 3 or more clinicians before diagnosis. 2 Do not contribute to this delay by requiring surgical confirmation before treatment.
Associated Conditions to Screen For
- Adenomyosis: Often coexists with endometriosis and requires MRI for diagnosis when ultrasound is equivocal (MRI sensitivity 78%, specificity 93%) 1, 4
- Cardiovascular risk: Women with endometriosis have increased risk for stroke (HR 1.34,95% CI 1.10-1.62) 1
- Ovarian cancer risk: Increased risk of clear cell, endometrioid, and low-grade serous ovarian cancers (0.7-1.6% lifetime risk) 3