'Essential' hypertension with hypokalemia. Caused by aldosterone-secreting adrenal adenoma.

Primary aldosteronism is a potentially curable cause of hypertension; it occurs in about 1% of hypertensive patients. In the case reported here, persistent hypokalemia developed in a 72-year-old man who had been treated for 13 years for essential hypertension. Investigation revealed elevated aldosterone level and reduced plasma renin activity. Computed tomography and selective angiography showed a tumor in the right adrenal gland. Aldosterone-secreting adenoma of the adrenal gland was diagnosed, and right adrenalectomy was performed. At a six-month follow-up examination, the patient's blood pressure and potassium level were normal.