What investigations are required in postmenopausal hirsutism?

Investigations Required in Postmenopausal Hirsutism

Postmenopausal women with hirsutism require comprehensive hormonal evaluation to rule out serious underlying causes, particularly androgen-secreting tumors of the ovaries or adrenal glands.

Initial Evaluation

• Detailed history focusing on onset and progression of hirsutism, associated symptoms (virilization, menstrual history, infertility), and medication use 1
• Physical examination to assess distribution and severity of hirsutism, signs of virilization (clitoromegaly, deepening voice), truncal obesity, and androgenic alopecia 1, 2
• Evaluation of metabolic parameters due to association with insulin resistance, hypercholesterolemia, and hypertension 2

Essential Laboratory Investigations

Hormonal Panel

• Serum total and free testosterone (preferably by tandem mass spectrometry) - elevated levels >5 nmol/L strongly suggest androgen-producing tumors 3
• Sex hormone-binding globulin (SHBG) - helps calculate free androgen index 1, 2
• Dehydroepiandrosterone sulfate (DHEA-S) - primarily reflects adrenal androgen production 1, 2
• Androstenedione - can be elevated in both ovarian and adrenal disorders 1, 2
• Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) - to confirm postmenopausal status 1
• Inhibin B - may be elevated in certain ovarian tumors 2

Additional Endocrine Testing

• Morning cortisol and ACTH - to evaluate adrenal function 1
• Tests to exclude Cushing syndrome (overnight dexamethasone suppression test or 24-hour urinary free cortisol) 2
• Thyroid function tests (TSH, free T4) - thyroid dysfunction can affect hormone metabolism 1
• Prolactin - may be elevated in pituitary disorders 1

Imaging Studies

• Transvaginal ultrasound - first-line imaging for ovarian assessment; may identify ovarian enlargement, masses, or polycystic changes 1, 4
• Magnetic resonance imaging (MRI) of the ovaries - when ultrasound is inconclusive or to better characterize ovarian lesions 2, 4
• Computed tomography (CT) or MRI of the adrenal glands - to evaluate for adrenal masses 2, 3
• Pituitary MRI - if central causes are suspected (e.g., elevated prolactin) 1

Special Considerations

• Ovarian hyperthecosis may elude standard imaging studies despite causing significant hyperandrogenism in postmenopausal women 5
• Benign ovarian tumors like cystadenofibroma can cause hyperandrogenism and should be considered even when initial imaging is unremarkable 4
• Rare conditions like hilus cell tumors and stromal luteomas may require surgical exploration for definitive diagnosis 6

Common Pitfalls to Avoid

• Failing to investigate new-onset hirsutism in postmenopausal women - this is never normal and requires thorough evaluation 2, 5
• Overlooking subtle ovarian abnormalities on imaging - repeat imaging or different modalities may be necessary 4, 5
• Attributing symptoms to polycystic ovary syndrome without excluding more serious causes 3
• Neglecting to consider adrenal sources of androgen excess 2, 3

Management Approach

• Referral to endocrinology and gynecology is warranted for all cases of postmenopausal hirsutism 1
• Surgical intervention (bilateral oophorectomy or adrenal tumor removal) is often necessary for definitive diagnosis and treatment of androgen-secreting tumors 3, 6
• Medical management with antiandrogens or GnRH analogs may be considered for women unfit for surgery or when the source of hyperandrogenism remains unidentified 2

Remember that postmenopausal hirsutism, especially when of recent onset, requires prompt and thorough investigation as it may signal serious underlying pathology including malignancy 2, 3, 4.