Addison's Disease Patient Presenting with Cushing's Syndrome Findings

ABSTRACT

A 24-year-old man with Addison’s disease, who was receiving replacement therapy with prednisolone, was admitted to our hospital due to findings of both hypocortisolism and hypercortisolism. Plasma adrenocorticotropic hormone (ACTH) was found to be high during and after withdrawal of prednisolone therapy. ACTH was not suppressed with 2 mg or 8 mg of dexamethasone. Gadolinium-diethylene triamine penta-acetic acid (Gd-DTPA)-enhanced magnetic resonance imaging of the pituitary showed hyperplasia or adenoma. Pituitary hyperplasia or adenoma with high ACTH level was considered to be the result of the insufficient therapy. The combination of hydrocortisone and bedtime dexamethasone reduced plasma ACTH levels and improved imaging findings. Since a reliable biomarker for monitoring the adequacy of replacement therapy has not yet been identified and current glucocorticoid replacement regimens do not mimic normal diurnal biorhythm of cortisol, some patients may require different glucocorticoid replacement regimens or formulas.