Pheochromocytoma Case Studies

Pheochromocytoma, a rare condition caused by a tumor in the adrenal medulla affecting the chromaffin cells, results in an excess production of catecholamines (epinephrine and norepinephrine) and metanephrines. The most immediate effect of this condition is severe hypertension, but other symptoms (such as headache, palpitations and excessive generalized sweating) can also appear.

If left untreated, pheochromocytoma may lead to hypertensive encephalopathy, cardiomyopathy, diabetes mellitus and even death – therefore adequate treatment should be pursued as soon as the correct diagnosis is established. Surgery is the primary and only valid approach, but a premedication step has to be undertaken prior to the procedure.

Medical preparation for surgery
The most important issue is adequate blood pressure control in order to avoid potential hypertensive crisis during intraoperative handling of the tumor, maintain stable blood pressure during surgery, but also to minimize any adverse effects of anesthesia.

Usually the pretreatment begins with α-blockers, and when suitable α-blockade is achieved, the patient can then be treated with β-blockers to achieve adequate control of the heart rate. Phenoxybenzamine, which is a nonselective α-blocker, is a drug of choice (albeit doxazosin or prazosin can also be used). It is administrated 7 to 10 days before surgery.

Β-blockers can be used only after α-blockade, otherwise the initial use of β-blockers results in unopposed stimulating activity of catecholamines on α-receptors, leading to life-threatening hypertensive crisis. Usually 10 mg of propranolol four times a day is used for β-blockade, which is later translated to daily long-acting