Which blood tests should be ordered to evaluate an elevated dehydroepiandrosterone sulfate (DHEA‑S) level in a post‑menopausal woman?

Blood Tests for Elevated DHEA-S in Postmenopausal Women

In a postmenopausal woman with elevated DHEA-S, immediately measure early-morning total and free testosterone in a specialized reference laboratory, and obtain adrenal CT imaging if DHEA-S exceeds 600 µg/dL, as this threshold strongly predicts an androgen-secreting adrenal adenoma. 1

Risk Stratification by DHEA-S Level

Critical Elevation (>600 µg/dL)

• Order high-resolution adrenal CT without delay when DHEA-S exceeds 600 µg/dL (≈16,000 nmol/L), as this concentration strongly suggests an androgen-secreting adrenal cortical adenoma—often associated with hypercorticism and requiring urgent surgical evaluation. 2, 3, 1
• Measure serum cortisol to assess for concurrent hypercortisolism, which frequently accompanies adrenal adenomas producing excess DHEA-S. 4

Moderate Elevation (200–600 µg/dL)

• Obtain early-morning (≈8 AM) fasting total and free testosterone in a specialized reference laboratory using liquid chromatography-tandem mass spectrometry (LC-MS/MS) or equilibrium dialysis, because routine commercial assays lack accuracy at female reference ranges. 1, 5
• Check 17-hydroxyprogesterone (17-OHP) at 8 AM to screen for non-classic congenital adrenal hyperplasia (21-hydroxylase deficiency), particularly in high-risk ethnic groups: Ashkenazi Jews (≈1:27), Hispanics (≈1:40), and Slavics (≈1:50). 4, 2
• Measure prolactin and TSH to exclude hyperprolactinemia and thyroid dysfunction as alternative causes of hormonal disturbance. 4, 1

Mild Elevation (<200 µg/dL)

• Assess for clinical signs of hyperandrogenism—hirsutism (quantified by Ferriman-Gallwey score), acne, androgenic alopecia, or virilization (clitoromegaly, voice deepening, increased muscle mass)—because even modest biochemical elevations can be clinically relevant. 6, 1
• Measure testosterone if any hyperandrogenic signs are present, as DHEA-S may be elevated in isolation or as part of generalized androgen excess. 1

Essential Hormonal Panel

• Total testosterone: Use specialized assay (LC-MS/MS); levels >200 ng/dL strongly suggest an androgen-secreting neoplasm and mandate immediate imaging of both ovaries and adrenals. 1, 5
• Free testosterone: More sensitive than total testosterone for detecting subtle androgen excess because it reflects variations in sex hormone-binding globulin (SHBG). 1
• 17-Hydroxyprogesterone (17-OHP): If elevated (>200 ng/dL), perform ACTH stimulation test; a stimulated level >1,000 ng/dL confirms non-classic congenital adrenal hyperplasia. 2, 5
• Prolactin: Exclude hyperprolactinemia as a cause of hormonal disturbance. 4, 1
• TSH and free T4: Exclude thyroid dysfunction, which can disrupt hormonal balance. 4, 7
• Cortisol: Baseline and, if Cushing syndrome is suspected, 24-hour urinary free cortisol or overnight dexamethasone suppression test. 2

Imaging Studies

• Adrenal CT (high-resolution protocol) is mandatory when DHEA-S >600 µg/dL, testosterone ≥200 ng/dL, or clinical suspicion points to an adrenal source. 2, 1
• Pelvic ultrasound is indicated when testosterone is elevated with normal or mildly elevated DHEA-S to detect ovarian hyperthecosis or steroid-cell tumors (≈0.2% of hyperandrogenic women, >50% malignant). 3, 1

Interpretation of Hormone Patterns

Normal DHEA-S with Elevated Testosterone

• Suggests ovarian source (ovarian hyperthecosis or tumor) rather than adrenal origin; proceed with pelvic ultrasound. 3, 1
• Ovarian hyperthecosis is typically associated with insulin resistance. 3, 1

Elevated DHEA-S with Normal Testosterone

• Consider adrenal hyperandrogenism without significant ovarian contribution; however, some postmenopausal women with prior PCOS maintain relatively higher testosterone despite declining ovarian function. 1
• Measure DHEA (not just DHEA-S), as poorly differentiated adrenal tumors may have higher circulating DHEA than DHEA-S. 2

Both DHEA-S and Testosterone Elevated

• Indicates generalized androgen excess; determine source with imaging (adrenal CT and pelvic ultrasound). 1
• If both are markedly elevated (DHEA-S >600 µg/dL and testosterone >200 ng/dL), perform both imaging studies immediately to localize the tumor. 1

Dynamic Testing (When Initial Evaluation Is Inconclusive)

• ACTH stimulation test: Administer 0.25 mg cosyntropin IV; measure cortisol and 17-OHP at baseline and 60 minutes to detect 21-hydroxylase deficiency or other steroidogenic enzyme defects. 6, 5
• Dexamethasone suppression test (2-day protocol): Obtain baseline pooled samples (three 20-minute intervals), administer dexamethasone 0.5 mg at lunch, dinner, and bedtime for 2 days, then repeat pooled sampling; >60% suppression of DHEA-S and >40% suppression of testosterone indicates adrenal source. 6
• GnRH agonist challenge: Rarely needed in postmenopausal women; assesses ovarian androgen output if ovarian source is suspected despite normal imaging. 6, 1

Critical Pitfalls to Avoid

• Do not assume adrenal origin solely because DHEA-S is elevated; ovarian tumors can co-secrete DHEA-S. 1
• Do not assume ovarian origin solely because testosterone is high with normal DHEA-S; rare pure testosterone-secreting adrenal adenomas exist. 1
• Do not rely on a single testosterone measurement if hyperandrogenic symptoms are present; repeat in a specialized laboratory using validated assays. 1, 5
• Do not delay imaging when DHEA-S >600 µg/dL or testosterone >200 ng/dL; these thresholds mandate urgent evaluation for neoplasm. 2, 3, 1

Medication and Exogenous Androgen Review

• Exclude exogenous androgen exposure: anabolic steroids, androgenic supplements (not detected by standard assays), danazol. 1
• Identify valproic acid as the only anticonvulsant known to raise testosterone levels. 4, 1
• Check for medications affecting SHBG: thyroid hormones, tamoxifen, raloxifene can artificially elevate total testosterone without true hyperandrogenism. 3, 5

Follow-Up and Monitoring

• If adrenal adenoma is confirmed, refer urgently for adrenalectomy (laparoscopic preferred for hormone-secreting lesions; open surgery for large or invasive tumors). 1
• If non-classic CAH is diagnosed, consider low-dose glucocorticoid therapy (dexamethasone 0.25–0.5 mg nightly or prednisone 5–7.5 mg nightly) for 2–3 months, then monitor every 3–4 months for one year. 1, 5
• If no tumor is found and PCOS history exists, recognize that postmenopausal women with prior PCOS maintain relatively higher testosterone and reduced estrogen-to-androgen ratio; monitor for metabolic and cardiovascular sequelae (fasting glucose, lipids, blood pressure annually). 1, 5