Unilateral adrenal hypersecretion of both aldosterone and cortisol in two first cousins with a syndrome of mineralocorticoid excess but without signs of hypercortisolism

A 38 years old woman and her first cousin, a 41 year old man, presented both with hypertension, hypokalemia, hyperaldosteronism, and low plasma renin activity in our Hospital. In both patients, plasma and urine aldosterone were constantly above the normal range, even on a high NaCl diet (250 mEq/day), while the plasma aldosterone response to postural changes was normal. In the female patient abdominal ultrasonic scan, CT scan, MRI, and adrenal gland phlebography were normal, but blood from the left adrenal vein contained 1002 pg/ml of aldosterone, versus 91 pg/ml in the contralateral one. Interestingly, the secretion of cortisol was also lateralized (plasma cortisol levels being of 28.8 mcg% in the left, 2.3 mcg% in the right adrenal gland), although neither clinical nor laboratory signs of hypercortisolism were present. Spironolactone treatment (100 mg/daily) completely reversed the syndrome of mineralocorticoid excess. After 2 years, patient has normal blood pressure and serum K+ levels. In the male patient MRI showed the picture of marked hyperplasia of the left adrenal gland. Also in this case, blood from the left adrenal vein contained more aldosterone and cortisol (1304 pg/ml and 119.1 mcg% respectively), than the right one (564 pg/ml of aldosterone, and 14.6 mcg% of cortisol, respectively), without clinical or laboratory signs of hypercortisolism. When the left gland was excised, microscopic and macroscopic subcapsular nodules were revealed. After 6 months from surgery, patient is still normotensives, with normal serum K+ levels and urinary Na+/K+ ratio. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.