Can Adrenal Tumors Cause Elevated Testosterone and Decreased Libido?
Yes, adrenal tumors can cause elevated testosterone levels, but they typically cause virilization symptoms rather than decreased libido—the low libido paradox occurs primarily in men receiving mitotane therapy for adrenal cancer, not from the tumor itself.
Understanding the Hormonal Effects
Androgen-Secreting Adrenal Tumors
Androgen-secreting adrenal tumors are rare but well-documented entities that produce excess testosterone and other androgens:
- Pure androgen-secreting adrenal tumors (PASATs) predominantly affect women (95% of cases) and present with virilization symptoms including hirsutism (95% of cases), menstrual dysfunction, and amenorrhea 1
- Testosterone levels are typically markedly elevated, often exceeding 200 ng/dL, with androstenedione levels >600 ng/dL in adenomas 2
- Dehydroepiandrosterone sulfate (DHEAS) is commonly elevated (>700 µg/dL in carcinomas) and serves as a key diagnostic marker 2, 1
Clinical Presentation Differs by Sex
In women, excess androgens from adrenal tumors cause:
In men, the clinical picture is different and more subtle, as excess androgens don't produce obvious virilization.
The Low Libido Connection: A Treatment Effect
The association between adrenal tumors and low libido is not from the tumor itself but rather from treatment:
- Mitotane therapy (the standard adjuvant treatment for adrenocortical carcinoma) causes hypergonadotropic hypogonadism in 80% of male patients 6
- This results in elevated SHBG, elevated LH, and decreased free testosterone despite normal or elevated total testosterone 6
- Erectile dysfunction occurs in 83% of men on mitotane therapy 6
- Androgen replacement therapy significantly improves sexual function in these patients 6
Diagnostic Approach
Biochemical Evaluation
When evaluating suspected androgen-secreting adrenal tumors 7, 8:
- Measure testosterone and androstenedione - Testosterone >200 ng/dL suggests adrenal adenoma
- Check DHEAS levels - Markedly elevated DHEAS (>700 µg/dL) suggests carcinoma 2
- Perform 1-mg overnight dexamethasone suppression test - These tumors typically don't suppress with dexamethasone 2
- Assess for co-secretion - Check 24-hour urine free cortisol and plasma metanephrines, as mixed secretion occurs 3, 9
Imaging Characteristics
- Tumors >7 cm diameter suggest malignancy 2
- However, malignancy cannot be excluded in smaller tumors 7
- Lesions with attenuation <10 HU on unenhanced CT are benign adenomas 8
- Inhomogeneous lesions >4 cm with HU >20 have high malignancy risk requiring multidisciplinary discussion 8
Malignancy Risk Assessment
Critical warning signs for adrenocortical carcinoma 1:
- Shorter disease duration (average 1.96 vs 4.51 years for benign)
- Larger tumor size (8.9 vs 4.9 cm)
- Predominant DHEAS elevation rather than testosterone
- Higher androgen/upper normal range ratios
Treatment Implications
Surgical resection is recommended for all androgen-secreting tumors 10, 7:
- Open adrenalectomy is preferred when carcinoma is suspected 7
- Complete R0 resection with locoregional lymphadenectomy for ACC 10
- Post-operative normalization of testosterone and resolution of symptoms occurs rapidly 3, 4
Post-Surgical Considerations
- Adjuvant mitotane is recommended for ACC with high-risk features (Ki67>10%) or incomplete resection 10
- Monitor for hypogonadism development in men receiving mitotane therapy 6
- Consider androgen replacement if hypogonadism and sexual dysfunction develop 6
Key Clinical Pitfalls
- Don't assume low libido is from tumor-produced testosterone - In men, this is almost always a treatment effect from mitotane, not the tumor itself
- Don't miss co-secretion - Up to 30% of cases secrete multiple hormones including cortisol 3, 9
- Don't delay workup in suspected malignancy - ACC confers poor outcomes, and expedient evaluation is critical 3
- Don't forget long-term follow-up - Surveillance should continue for at least 10 years after resection 10