A Case of Ectopic ACTH Syndrome Caused by Thymic Carcinoid with Marked Fluctuation in Hormone Production

The frequency of reports with ectopic ACTH syndrome is increasing year by year. But the intermittent function by hormone producing tumor has been reported rarely. We report a patient with ectopic ACTH syndrome caused by a carcinoid tumor of the thymus in whom remarkable fluctuating hormonal production was closely associated with the fluctuation of clinical features such as pigmentation, acne, edema, polyuria, and hypokalemia.