All about Pheochromocytoma Clinical Features Diagnosis Treatment

Definition

A tumor derived from neural crest cells of the sympathetic nervous system that is responsible for about 0.1% to 2% of all cases of hypertension. Catecholamine-secreting tumors that arise from chromaffin cells of the adrenal medulla and the sympathetic ganglia are referred to as “pheochromocytomas” and “extra-adrenal catecholamine-secreting paragangliomas” (“extra-adrenal pheochromocytomas”), respectively Pheochromocytomas are a group of cells which produce and secrete catecholamines. They are derived from adrenal medulla or chromaffin cells of the sympathetic ganglia. There is sinus tachycardia, bradycardia, supraventricu­lar arrhythmias, ventricular premature contractions, angina and acute myocardial infarction.

CLINICAL PRESENTATION —

• The most common feature of pheochromocytoma is hypertension and paroxysmal hypertension which may be very disturbing.
• It is a correctable cause of hypertension.
• Untreated pheochromocytomas may be fatal. Pheochromocytomas are situated in the adrenal medulla or in abdomen near the celiac, superior me­senteric and inferior mesenteric ganglia (sympathetic ganglia).
• It occurs at all ages but common in young age. It is more common in females.
• There is labile hypertension, seizure disorders, anxiety attacks. Sometimes it is detected during surgery or after trauma.
• There is headache, excessive sweating and palpita­tions.
• There may be pain in chest and abdomen, with nau­sea and vomiting.
• There may be sudden flushing.
• Pheochromocytoma is usually suggested by the history in a symptomatic patient, discovery of an incidental adrenal mass, or the family history in a patient with familial disease.

Diagnosis

•  The patient’s urine or blood is tested to determine whether it contains excessive levels of catecholamines or their metabolites.
• · Vanillylmandelic acid, metanephrines, unconjugated and free catecholamines are esti­mated in urine.
• · Plasma catecholamines and plasma metanephrines may be measured for diagnosis.

When to suspect pheochromocytoma —

• Hyperadrenergic spells (eg, self-limited episodes of nonexertional palpitations, diaphoresis, headache, tremor, or pallor)
• Resistant hypertension
• A familial syndrome that predisposes to catecholamine-secreting tumors (eg, MEN2, NF1, VHL)
• A family history of pheochromocytoma
• An incidentally discovered adrenal mass Hypertension and diabetes Pressor response during anesthesia, surgery, or angiography Onset of hypertension at a young age (eg, <20 years)
• Idiopathic dilated cardiomyopathy
• A history of gastric stromal tumor or pulmonary chondromas (Carney triad)

Treatment Pheochromocytoma

• Phenoxybenzamine, an alpha receptor blocker, in dose of 10 mg 12 hourly, increasing 10 mg every few days, till blood pressure is controlled and paroxysms disappear.
• For tachycardia, after alpha blockers, beta blockers may be given in low dose.
• The tumors may be localized by eT, MRI and re­moved surgically.
• Once a pheochromocytoma is diagnosed, all patients should be operated on after appropriate medical preparation.
• Extirpating a pheochromocytoma is a high-risk surgical procedure, and an experienced surgeon/anesthesiologist team is required.