Conn’s syndrome produces high blood pressure (hypertension), which is often resistant to treatment with common blood pressure medications. It may also cause problems with low blood potassium levels. The syndrome is caused most commonly by a small benign (non-cancerous) tumour in one adrenal gland (called an adenoma).
Specialised blood tests, measuring blood aldosterone and renin levels, and occasionally more sophisticated tests, are needed to diagnose the syndrome. CT or MRI scans are then used to see which adrenal gland contains the adenoma. Specialised blood tests, called venous sampling, are then usually necessary to confirm that the gland containing the mass is producing too much aldosterone hormone.
Although Conn’s syndrome can be controlled with a specific medication called spironolactone, surgical removal of the affected gland is the definitive curative treatment. This should be done using a minimally invasive (laparoscopic) approach.