Laboratory Tests for Adenomyosis
No specific laboratory tests are required or recommended for the diagnosis of adenomyosis—this is fundamentally an imaging and clinical diagnosis.
Why Laboratory Tests Are Not Part of Adenomyosis Diagnosis
Adenomyosis is diagnosed through a combination of clinical presentation (abnormal uterine bleeding, dysmenorrhea, pelvic pain) and imaging findings on transvaginal ultrasound or MRI, not through blood work or other laboratory markers 1, 2, 3. The disease represents benign invasion of endometrial glands and stroma into the myometrium, which does not produce characteristic laboratory abnormalities 1.
Laboratory Tests That May Be Indicated for Associated Conditions
While adenomyosis itself requires no labs, you should obtain laboratory studies to:
1. Assess the consequences of abnormal uterine bleeding:
- Complete blood count (CBC) to evaluate for anemia secondary to heavy menstrual bleeding, which is present in many women with adenomyosis 1, 3
- Ferritin and iron studies if anemia is confirmed, to guide iron replacement therapy 1
2. Exclude alternative or coexisting causes of abnormal bleeding:
- Thyroid-stimulating hormone (TSH) to rule out thyroid dysfunction as a contributor to menstrual irregularity 4, 5
- Prolactin if there is suspicion of hyperprolactinemia causing ovulatory dysfunction 4, 5
- Pregnancy test (β-hCG) in all reproductive-age women with abnormal bleeding before proceeding with imaging or treatment 4, 5
3. Evaluate for endometrial pathology when indicated:
- Endometrial biopsy (a tissue diagnosis, not a "lab test") is warranted if the patient is ≥45 years old, has risk factors for endometrial cancer (obesity, diabetes, hypertension, unopposed estrogen), or has endometrial thickness ≥10 mm on ultrasound 4, 5
- This is critical because adenomyosis frequently coexists with endometrial hyperplasia or malignancy, and imaging alone cannot reliably distinguish these entities 6, 1
The Diagnostic Algorithm for Adenomyosis
Step 1: Obtain a focused history for heavy menstrual bleeding, dysmenorrhea, chronic pelvic pain, and infertility 1, 3
Step 2: Perform transvaginal ultrasound (combined with transabdominal if needed) during the early proliferative phase (days 4–6) when the endometrium is thinnest, to optimize visualization of myometrial features and the junctional zone 7, 5
- Transvaginal ultrasound using MUSA criteria has 82.5% sensitivity and 84.6% specificity for adenomyosis 7
- Look for asymmetric myometrial thickening, heterogeneous myometrial echotexture, subendometrial linear striations, myometrial cysts, and globular uterine enlargement 1, 8
Step 3: If ultrasound is inconclusive or adenomyosis obscures the endometrium, proceed to MRI pelvis (preferably with gadolinium and diffusion-weighted sequences), which has 78–93% sensitivity and 67–93% specificity 6, 7
Step 4: Consider endometrial biopsy if the patient meets criteria outlined above (age ≥45, risk factors, thickened endometrium) to exclude coexisting endometrial pathology 4, 5
Common Pitfalls to Avoid
Do not order CA-125 or other tumor markers for adenomyosis—these are not diagnostic and may be mildly elevated in benign conditions including adenomyosis and endometriosis, leading to unnecessary anxiety and testing 1
Do not accept imaging performed during the secretory phase or menstruation as optimal for adenomyosis diagnosis, because endometrial thickening during these phases obscures myometrial detail 7
Do not rely on ultrasound alone if coexisting fibroids are present—sensitivity for adenomyosis drops from 97.8% to 33.3% when leiomyomas are present, and MRI should be obtained 7
Do not skip endometrial sampling in high-risk patients even if imaging suggests adenomyosis, because adenomyosis frequently coexists with endometrial hyperplasia or cancer, and imaging cannot reliably differentiate these 6, 4, 1