Pheochromocytoma and Paraganglioma

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine neoplasms. Approximately 85% of PPGLs are localized to the adrenal glands; the remaining 15% are located along the great vessels extending from the skull base to the pelvis. Parasympathetic PGLs are usually biochemically silent and localized between the skull base and upper mediastinum. Sympathetic PPGLs usually hypersecrete catecholamines, and most are localized from the lower mediastinum to the pelvis. In the era of cross-sectional imaging, the majority of adrenal pheochromocytomas are discovered incidentally on imaging obtained for non-adrenal reasons. Less commonly, patients with PPGLs present with sign and symptoms of catecholamine hypersecretion. Biochemical testing for fractionated metanephrines and catecholamines is indicated in all patients with signs and symptoms consistent with catecholamine hypersecretion. When biochemical testing documents catecholamine excess, localization should start with computed tomography (CT) of the abdomen and pelvis. If a solitary adrenal mass consistent with pheochromocytoma (e.g., lipid poor and vascular) is identified, further imaging studies are usually not needed, whereas if the CT of the abdomen and pelvis identifies a mass consistent with a paraganglioma, then total body imaging is indicated to identify additional paragangliomas or metastatic disease. Most adrenal pheochromocytomas <8-cm in diameter can be resected by a minimally invasive approach, whereas most paragangliomas require a variety of surgical approaches based on location and surgical expertise. Because germline pathogenic variants in genes that predispose to PPGL are present in at least 40% of patients with these tumors, germline genetic testing should be considered and discussed with all patients.