What is the recommended diagnostic approach for a patient suspected of having hyperandrogenism (elevated testosterone levels), including optimal timing and necessary blood tests?

Diagnostic Approach for Hyperandrogenism (Elevated Testosterone)

For suspected hyperandrogenism, obtain a morning total testosterone level between 8-10 AM and repeat if elevated to confirm the finding, as testosterone levels vary significantly. 1

Initial Blood Tests

Essential First-Line Testing

• Morning total testosterone (8-10 AM): This is the mandatory first test and should be repeated if elevated to confirm the diagnosis 1
• Free testosterone by equilibrium dialysis (gold standard) or calculated free testosterone (cFT) with SHBG: Particularly important in obese patients, with pooled sensitivity of 0.89 and specificity of 0.83 for detecting biochemical hyperandrogenism 1
• DHEAS: Measure when total testosterone is twice the upper limit of normal to distinguish adrenal from ovarian sources 1, 2

Technical Considerations

• Use LC-MS/MS methods rather than direct immunoassays for superior accuracy 1
• If testosterone is markedly elevated but clinical signs don't match, suspect laboratory interference and consider diethyl ether extraction prior to immunoassay 3

Severity-Based Diagnostic Algorithm

Mild Hyperandrogenism (Testosterone <2x Upper Limit)

• LH and FSH: Evaluate for polycystic ovary syndrome (PCOS), the most common cause 1, 4
• 17-OH progesterone: Consider if non-classical congenital adrenal hyperplasia (NCCAH) is suspected 4
• Prolactin: Exclude hyperprolactinemia in women with recent oligomenorrhea 4

Severe Hyperandrogenism (Testosterone >2x Upper Limit or Rapid Virilization)

Immediately evaluate for androgen-secreting tumors with the following comprehensive panel 1:

• DHEAS
• Testosterone
• 17β-estradiol
• 17-OH progesterone
• Androstenedione
• 11-deoxycorticosterone
• Progesterone

DHEAS interpretation 2:

• DHEAS >600 mg/dL: Suggests androgen-secreting adrenal cortical adenoma
• Normal DHEAS with elevated testosterone: Consider ovarian hyperthecosis or ovarian tumor

Additional Hormonal Testing Based on Clinical Presentation

When Cushing's Syndrome is Suspected

• 1 mg dexamethasone suppression test: Give at 11 PM, measure serum cortisol at 8 AM 1
  • Cortisol <50 nmol/L: Excludes cortisol hypersecretion
  • Cortisol >138 nmol/L: Indicates cortisol hypersecretion
• 24-hour urinary free cortisol: Alternative screening method 4

For Adrenal Incidentalomas with Hyperandrogenism

• Plasma or 24-hour urinary metanephrines: Screen for pheochromocytoma if adrenal mass has ≥10 Hounsfield units on non-contrast CT 1
• Aldosterone/renin ratio: If hypertension or hypokalemia present 1

Imaging Studies

Pelvic Ultrasonography

• Indicated when normal DHEAS with elevated testosterone suggests ovarian source 1, 2
• Essential for evaluating ovarian tumors 1

Adrenal Imaging (CT or MRI)

• Recommended when DHEAS >600 mg/dL 1
• Required when androgen-secreting adrenal tumor suspected 1

Baseline Assessments Before Treatment Initiation

If testosterone replacement or hormonal therapy is being considered:

• Hemoglobin/hematocrit: Baseline measurement mandatory 1
• Cardiovascular risk assessment: Lipids, blood pressure, glucose 1
• PSA in men >40 years: If considering testosterone therapy 5

Common Pitfalls to Avoid

• Don't rely on total testosterone alone in obese patients: SHBG is often reduced with obesity, metabolic syndrome, or family history of diabetes, leading to falsely normal total testosterone despite elevated free testosterone 2
• Don't dismiss very high testosterone without virilization: Laboratory interference should be suspected, but ovarian steroid-cell tumors can present with extremely high testosterone without virilization signs 3
• Don't forget timing: Testosterone must be drawn in the morning (8-10 AM) as levels vary diurnally 1
• Don't use unreliable assays: Direct immunoassays are less accurate than LC-MS/MS methods 1, 6