Pheochromocytoma and paraganglioma-an update on diagnosis, evaluation, and management

Abstract

Pheochromocytomas and paragangliomas (PPGLs) generally grouped together are rare catecholamine-secreting endocrine tumors. Symptoms of catecholamine excess are non-specific and therefore a high index of suspicion in children with sustained hypertension, family history of endocrine tumors, or features of syndromes associated with PPGLs leads to a timely diagnosis and treatment. Free metanephrines in the plasma or 24-h urine are the preferred tests to establish catecholamine excess. Considerations for false-positive conditions improve diagnostic yield and accuracy. Functional imaging, targeting either specific cell membrane transporters or vesicular catecholamine transport systems, is indicated for incidental lesions suspicious for PPGLs with inconclusive biochemical testing, assessment of regional extension or multifocality, and exclusion of metastases. Surgery is the mainstay of treatment for PPGLs. Preoperatively, sequential use of alpha adrenergic receptor blockade and volume expansion followed by beta blockade is mandatory to reduce intraoperative intravascular instability and blood pressure fluctuation due to tumor manipulation. Since genetic mutations have been reported in tumor susceptibility genes in nearly 50% of patients with PPGLs, genetic counselling and testing should be considered in all patients with a confirmed tumor.

Keywords: Catecholamines; Hypertension; Neuroendocrine tumors; Paraganglioma; Pheochromocytoma; Tumors.