Asymptomatic normotensive primary aldosteronism. Case report.

We report a case of primary aldosteronism in a 30-year-old woman without hypertension or any other characteristic symptoms. The condition was first suspected by hypokalemia (2.6 mEq/liter), which was incidentally found by routine checkup. There was evidence of suppressed plasma renin activity (PRA) and elevated plasma aldosterone levels. However, the blood pressure never reached a hypertensive level, and the circulating blood volume was within a normal range. A functioning right adrenal tumor was diagnosed by adrenal scintigraphy, computerized x-ray tomography, and adrenal venography. Adrenal venous catheterization suggested an aldosteronoma, which was confirmed by lateralized hypersecretion of aldosterone. After removal of the benign adenoma, the biochemical abnormalities were corrected, yet the blood pressure remained much the same. Hypertension is not necessarily a sign of primary aldosteronism.