ACTH-independent Cushing's syndrome is caused by autonomous production of cortisol, usually by an adrenal adenoma, carcinoma, or primary adrenocortical micronodular dysplasia. Cushing's syndrome due to adrenocortical adenoma usually has a unilateral lesion and contralateral site becomes atrophic. We report a rare case of Cushing's syndrome caused by ACTH independent bilateral adrenocortical adenomas. A 48=year-old woman presented with Cushingoid features, diabetes mellitus and hypertension.
Urinary free cortisol and 17-hydroxycorticosteroid excretion were 365.4ug/day and 16.2mg/day, respectively. Both were not suppressed after administration of high-dose dexamethsone. Plasma ACTH was 3.5pg/ml. Abdominal C-T revealed well defined bilateral adrenal tumors 4.0cm in diameter on the ventral side of the fight renal upper pole and 2.0 cm in diameter on the ventral side of left renal upper pole. Bilateral partial adrenalectomy was performed. The both adrenal glands showed all the pathologic features of adenoma.