Desmopressin Stimulation Test as a Valuable Tool in Establishing Cushing Syndrome Etiology

The study highlights the utility of the desmopressin stimulation test in determining the etiology of Cushing Syndrome (CS), particularly in cases with inconclusive ACTH levels and negative pituitary imaging. A case of a 30-year-old female with hypercortisolism and ambiguous diagnostic results is presented. Despite normal ACTH levels and negative brain MRI, the desmopressin test indicated an adrenal source of hypercortisolism, confirmed by an adrenal CT scan showing a right adrenal mass. Post-adrenalectomy, the patient showed significant clinical improvement. The authors advocate for the desmopressin stimulation test as a non-invasive, effective tool in identifying CS etiology when traditional methods yield discordant results.