Newer diagnostic techniques and problems in Cushing's disease.

Area of Science:

• Endocrinology
• Neurosurgery
• Diagnostic Medicine

Background:

• Cushing's disease diagnosis is evolving, complicated by transsphenoidal surgery and normal imaging in some cases.
• Accurate diagnosis and differential diagnosis are crucial for effective Cushing's disease management.

Purpose of the Study:

• To outline the current best diagnostic strategies for suspected Cushing's disease.
• To evaluate the utility of various diagnostic tests in hypercortisolism.

Main Methods:

• Review of diagnostic approaches for Cushing's disease.
• Evaluation of late-night salivary cortisol, 24-hour urinary free cortisol (UFC), L-dexamethasone suppression test (L-DST), and CRH stimulation tests.
• Assessment of inferior petrosal sinus sampling (IPSS) with CRH stimulation for localization.

Main Results:

• Late-night salivary cortisol and 24-hour UFC are recommended for initial hypercortisolism screening.
• L-DST is less reliable for excluding Cushing's disease, especially in mild cases.
• Combined L-DST and CRH stimulation may aid in equivocal cases.
• IPSS with CRH is valuable for confirming Cushing's disease and localizing adenomas when imaging is inconclusive.

Conclusions:

• A multi-test approach is essential for accurate Cushing's disease diagnosis.
• Salivary cortisol and UFC are primary screening tools.
• Advanced tests like IPSS are crucial for definitive diagnosis and localization in challenging cases.