Pheochromocytoma Support Group

A pheochromocytoma (also phaeochromocytoma, English spelling) is a tumor of the medulla of the adrenal glands originating in the chromaffin cells, which secretes excessive amounts of catecholamines, usually epinephrine and norepinephrine. Extra-adrenal paragangliomas (often described as extra-adrenal pheochromocytomas) are closely related, though less common, tumors that originate in the ganglia of the sympathetic nervous system and are named based upon the primary anatomical site of origin.

The diagnosis can be established by measuring catecholamines and metanephrines in plasma or urine. Care should be taken to rule out other causes of adrenergic excess like hypoglycemia, stress, exercise, and drugs affecting the catecholamines like methyldopa, dopamine agonists, or ganglion blocking antihypertensives. Various foodstuffs (e.g. vanilla ice cream) can also affect the levels of urinary metanephrine and VMA (vanillyl mandelic acid). Imaging by computed tomography or a T2 weighted MRI of the head, neck, and chest, and abdomen can help localize the tumor. One diagnostic test used in the past for a pheochromocytoma is to administer clonidine (Catapres®), a centrally-acting alpha-2 agonist used to treat high blood pressure. Clonidine mimics catecholamines in the brain, causing it to reduce the activity of the sympathetic nerves controlling the adrenal medulla. A healthy adrenal medulla will respond to clonidine by reducing catecholamine production; the lack of a response is evidence of pheochromocytoma. Another test is for the clinician to press gently on the adrenal gland. A pheochromocytoma will often release a burst of catecholamines, with the associated signs and symptoms quickly following. This method is NOT recommended

Pheochromocytomas occur most often during young-adult to mid-adult life. Less than 10% of pheochromocytomas are malignant (cancerous).

These tumors can form a pattern with other endocrine gland cancers which is labeled multiple endocrine neoplasia (MEN). Pheochromocytoma may occur in patients with MEN 2 and MEN 3. VHL (Von Hippel Lindau) patients may also develop these tumors.

Surgical resection of the tumor is the treatment of first choice. Given the complexity of perioperative management, and the potential for catastrophic intra and postoperative complications, such surgery should be performed only at centers experienced in the area. In addition to the surgical expertise that such centers can provide, they will also have the necessary endocrine and anesthesia resources as well.