In a patient with an empty sella turcica, no infarction or hemorrhage, and normal morning cortisol and ACTH levels, should we perform a cosyntropin stimulation test, refer to neurosurgery, and order serum free thyroxine and prolactin?

Management of Empty Sella Turcica with Normal AM Cortisol and ACTH

In a patient with empty sella turcica and normal morning cortisol and ACTH, you should obtain serum free thyroxine (fT4), TSH, prolactin, and IGF-1 to complete the hormonal evaluation, but a cosyntropin stimulation test is NOT needed if the 8 AM cortisol is >15 mcg/dL, and neurosurgical referral is NOT indicated in the absence of mass effect or visual symptoms.

Hormonal Testing Strategy

Cortisol Axis Assessment

The decision to perform cosyntropin stimulation testing depends entirely on the actual 8 AM cortisol value:

• If 8 AM cortisol >15 mcg/dL: Adrenal insufficiency is excluded; no cosyntropin test needed 1
• If 8 AM cortisol 3-15 mcg/dL: Perform cosyntropin stimulation test 1
• If 8 AM cortisol <3 mcg/dL: Adrenal insufficiency is confirmed 1

Critical caveat: The cortisol must be drawn at 8 AM specifically, as cortisol levels peak between 6:00-8:30 AM, and meals reduce cortisol levels 1. A "normal AM cortisol" drawn at noon or other times is not interpretable for excluding adrenal insufficiency.

For cosyntropin testing when indicated, stimulated cortisol thresholds of <18 mcg/dL (or 14-15 mcg/dL for certain assays) at 30 or 60 minutes post-injection suggest adrenocortical insufficiency 1, 2.

Complete Pituitary Hormone Panel

You should obtain the following tests regardless of cortisol results 1, 3:

• Thyroid axis: Free T4 and TSH
• Prolactin: To assess for hyperprolactinemia or stalk dysfunction
• Gonadal axis: Testosterone (males) or estradiol with FSH/LH (premenopausal women)
• Growth hormone axis: IGF-1

This comprehensive approach is justified because:

• Pituitary insufficiency occurs in 52% of patients with primary empty sella syndrome overall 3
• Recent 2025 data shows secondary adrenal insufficiency and hypogonadism are significantly more common in complete empty sella (≥50% CSF filling) 4
• Hormonal deficiencies can be present even when one axis appears normal 5
• The affected-axis rates often exceed 10% and may reach 50% 4

Neurosurgical Referral

Neurosurgical referral is NOT indicated for empty sella without mass lesions, as your patient has no infarcts or hemorrhages 6, 1.

Surgical referral is only appropriate for:

• Visual disturbances or optic nerve/chiasm compression
• Tumor proximity to chiasm (<5 mm)
• Documented tumor enlargement on serial imaging
• Pituitary apoplexy

Empty sella itself is a benign radiological finding and does not require surgical intervention 6.

Follow-Up Strategy

If initial hormonal testing is normal, repeat evaluation should occur:

• At 6 months initially
• Then annually thereafter 1

This is particularly important because hormonal deficiencies can develop progressively over time in empty sella syndrome 5.

Key Clinical Pitfalls to Avoid

1. Timing error: Do not accept "normal AM cortisol" unless specifically drawn at 8 AM 1
2. Incomplete evaluation: Testing only cortisol/ACTH misses other common deficiencies 3, 4
3. Premature reassurance: Normal baseline testing doesn't exclude future hormone deficiency development 5
4. Gender considerations: Women are more likely to develop gonadal dysfunction (34.1% vs 21.9% in men) 5