Hypokalemia secondary to primary hyperaldosteronism in a renal transplant recipient

We describe a patient who developed persistant hypokalemia after renal transplantation that was initially attributed to diuretics and/or steroids. However after stopping the diuretic, the patient continued to have urinary losses of potassium (less than 30 mEq/day) at a time when the serum potassium was only 2.4 mEq/l and high urinary chloride (33 mEq/day) suggesting that the diuretics were not responsible for the hypokalemia and the metabolic alkalosis. The results of these simple laboratory tests and the presence of persistent severe hypokalemia prompted additional studies (peripheral renin activity; plasma aldosterone levels; and CT scan) that led to the diagnosis of left adrenal gland adenoma. Surgical removal of the adrenal adenoma led to the normalization of the serum potassium and a fall in the total CO2 content in plasma. To our knowledge this is the first report of a case of hypokalemia secondary to primary hyperaldosteronism in a renal transplant recipient.