By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.
This is a very small benign tumor of an adrenal gland, which secretes excessive amounts of a hormone called aldosterone, and which is a rare cause of hypertension. The clue to the condition is a low blood potassium. Since potassium is part of any routine blood measurement, it should be relatively easy to diagnose, but it's surprising how many patients go for years with low potassium readings before it is diagnosed.
The function of aldosterone is to regulate sodium and potassium balance. It acts on the kidney to retain sodium in exchange for potassium, which is excreted in the urine. When aldosterone is produced in excess the retained sodium makes the blood pressure go up, and there is depletion of potassium.
The tumor is diagnosed first by measurement of aldosterone in the urine and of renin in the blood. The other part of the diagnostic procedure is the visualization of the tumor, which is best performed by a CT (computerized tomography) scan of the adrenal glands. The treatment is to remove the adrenal gland in which the tumor is growing by a surgical operation, which usually results in a permanent cure of the hypertension.