Pheochromocytoma and Paraganglioma

Abstract

Catecholamine secreting tumors pheochromocytomas and paragangliomas (PPGLs) arise from the adrenal medulla and paravertebral ganglia of the sympathetic chain. Although PPGLs are rare, they may have severe and even fatal cardiovascular consequences. In patients with PPGLs, excessive release and high levels of circulating catecholamines are responsible for the classical symptoms of hyperadrenergic spells which among others include tachycardia, headache, and sweating and which may occur spontaneously or may be provoked by different physical or chemical triggers. When PPGLs are suspected, biochemical testing should precede imaging procedures and choosing the most appropriate laboratory test is crucial for reliable detection or exclusion of the tumor. Initial biochemical testing should include measurements of plasma free or urine fractionated metanephrines. After establishing a clear biochemical diagnosis, the next step is to localize the tumor. Computed tomography is recommended as the first-choice anatomical modality because of its excellent spatial resolution. Adequate preparation prior to surgical resection of the PPGLs is of relevance. Preoperative alpha-blockade has been advocated to lower blood pressure and minimize intra-operative hypertension. Beta-adrenoceptor blockade is indicated to control sinus tachycardia and other catecholamine-induced tachyarrhythmias, but only after several days of alpha-adrenoceptor blockade has been installed. After successful resection of PPGLs, patients should undergo long-term follow-up to detect recurrent tumors, new tumors, or metastatic disease.