Can adrenal metastases cause elevated catecholamines?
QUESTION-Can metastatic cancer to the adrenal gland that is invasive and growing
rapidly cause elevated catecholamines/ metanephrines in the urine that issimilar to labs expected in Pheo ? Rami Mortada
RESPONSE- This is an excellent question, the answer is usually not. In other words, patients with metastatic tumors to adrenal gland do not present with elevated catecholamine levels.
If there is a question whether elevated catecholamines could be related to pheochromocytoma or not, I would suggest clonidine test.
This test is currently the standard way to determine if high basal levels of plasma catecholamines are due to an idiopathic hyperadrenergic state or to a pheochromocytoma. The patient is given 0.3 mg clonidine/70 kg (i.e. approximately 4.3 mg/kg) by mouth. Blood pressure and heart rate are monitored every 5 minutes for 20 minutes before, and every 15 minutes for 3 hours after administering of clonidine. Blood is drawn via an i.v., for determination of catecholamines and metanephrines before and at 3 hours after clonidine is given. This dose of clonidine causes a fall in blood pressure in most patients with hypertension of any cause. Plasma norepinephrine levels fall in most patients with hypertension, but in patients with pheochromocytoma, because of unregulated secretion of catecholamines by the tumor, plasma norepinephrine levels remain unchanged, decrease by less than 50% when compared to baseline, or increase.
This is due to clonidine¹s action to reduce central sympathetic outflow and thereby reduce plasma levels of norepinephrine in control group or subjects with sympathetic hyperactivity. This does not occur in patients with a pheochromocytoma since the tumor continues to release catecholamines even in the absence of sympathetic nerve stimulation. The clonidine test has sensitivity of 97% and specificity of 67%.. Please measure NE and MNM:
1. If NMN below URL or 40% decrease compare to baseline no pheo
2. If NE below URL or 50% decrease compare to baseline no pheo.
3. If obese, do not give more than 0.5 mg of clonidine.
4. Use IVF saline during the test of hypotension.
5. Stop any antihypertensive medication in AM of the day of the test.
Karel Pacak, MD, PhD, DSc