Overt diabetes mellitus in a patient with combined primary aldosteronism and Cushing's syndrome.

Although there are some case reports of combined aldosterone and cortisol producing adrenal tumor, overt diabetes mellitus has been rarely described. A 55-year-old hypertensive woman had hypokalemia and overt hyperglycemia without Cushingoid clinical features. The body mass index was 18.2 kg/m2, fasting blood glucose was 302 mg/dl and hemoglobin A1c was 11.6%. Endogenous insulin secretion was well preserved, whereas insulin sensitivity measured by short insulin tolerance test was markedly impaired. A solitary left aldosterone- and cortisol-producing adrenal tumor was diagnosed. We described a rare case of overt diabetes mellitus in a patient with combined primary aldosteronism and Cushing's syndrome.