Abstract: | A case of Cushing's syndrome due to huge adrenocortial multinodular hyperplasia who was shown to be hyperresponsive to ACTH administration, unresponsive to metyrapone administration and resistant to dexamethasone high dose suppression was reported. After two years' duration of his symptoms, the multinodular adrenals weighing 161 g in total were removed by bilateral adrenalectomy which abolished his symptoms. Postoperatively, plasma ACTH rose gradually to above normal levels, suggesting the presence of primary disorder in the hypothalamus-pituitary axis. |