A 41-yr-old female with presumed Cushing's syndrome was found to have a diurnal cortisol rhythm characterized by low values at 8:00 a.m. and consistently high values at 4:00 p.m. and midnight. Hourly sampling of plasma cortisol over 24 hr confirmed this rhythm, as did measurement of urinary free cortisols in samples collected every 6 hr over 24 hr. Hypercortisolemia was not suppressed by 2 mg of dexamethasone given every 6 hr for 24 hr. the adrenal tissue was responsive to ACTH. lodocholesterol scanning revealed unilateral activity, and the patient's syndrome was cured by resection of an adrenal adenoma. In this patient a diurnal cortisol secretory pattern was present due to the secretory activity of the adenoma. The cause of the abnormal but persistent diurnal pattern is unknown.
All Science Journal Classification (ASJC) codes
- Endocrinology, Diabetes and Metabolism