PHEOCHROMOCYTOMA AND PARAGANGLIOMA

Objective: Pheochromocytomas (PHEOs) and paragangliomas (PGLs) are neural crest cell tumors associated with catecholamine production and assessed by a metanephrine/methoxytyramine measurement. This review summarizes the genetics of these tumors. Methods: Case presentation, review of the relevant literature, and bullet point conclusions. Results: Genetic research over the past 10 years has led to a better understanding of the pathogenesis of these tumors, currently associated with 20 susceptibility genes (both somatic and germ-line mutations). Although most of these genes can be divided into two clusters (clusters 1 and 2), recent data suggest that all mutations converge on the hypoxia-inducible factor signaling pathway. Most of the susceptibility genes are well characterized and associated with specific clinical presentations, including biochemical phenotype, tumor location and behavior, as well as neoplasms or similar characteristics. Correct and early detection of hereditary PHEO/PGL is paramount, as early diagnosis leads to improved and focused treatment, along with better outcomes. However, missed or delayed diagnosis of hereditary PHEO/PGL forestalls proper treatment and results in multiple, recurrent, or metastatic tumors and avoidable complications in some patients. Conclusion: Early diagnosis allows prompt screening for potentially lethal cancers associated with specific gene mutations and makes genetic testing more readily available to first-degree and other relatives of an index patient. Thus, understanding the genetics of these tumors is an essential part of endocrinology.