A case of systemic lupus erythematosus in which Cushing's syndrome caused by adrenal adenoma accidentally occurred during long-term maintenance therapy with corticosteroids.

A 30-year-old female patient had been administered 5-mg/day prednisolone for systemic lupus erythematosus. She developed hypertension, dyslipidemia, moon face, central obesity, hypertrichosis, and impaired glucose tolerance. Although iatrogenic Cushing syndrome was initially suspected, we made a diagnosis of Cushing syndrome caused by a right adrenal adenoma, on the basis of the endocrine function test result and imaging findings. After surgery, the Cushingoid signs disappeared. Autoimmune diseases are often treated with corticosteroids; therefore, a differential diagnosis of primary Cushing syndrome should be made adequately.