Cushing's syndrome due to adrenal adenoma with persistent diurnal cortisol secretory rhythm.
A 41-yr-old female with presumed Cushing's syndrome was found to have a diurnal cortisol rhythm characterized by low values of 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. Iodocholesterol 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.
D015065:17-Hydroxycorticosteroids / Q000652:urine; D015068:17-Ketosteroids / Q000652:urine; D000236:Adenoma / Q000150:complications*; D000310:Adrenal Gland Neoplasms / Q000150:complications*; D000311:Adrenal Glands / Q000187:drug effects; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000328:Adult; D002940:Circadian Rhythm; D003480:Cushing Syndrome / Q000209:etiology / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*
D015065:17-Hydroxycorticosteroids; D015068:17-Ketosteroids; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone