Emerging molecular markers of metastatic pheochromocytomas and paragangliomas.

Metastatic pheochromocytoma/paraganglioma (PPGL) represents a major clinical challenge due to limitations in accurate diagnostic tools and effective treatments. Currently, patients classified at high-risk by means of clinical, biochemical and genetic criteria, require a lifelong monitoring, while it remains difficult to determine the metastatic potential of PPGL only on the basis of histopathological features. Thus, tumor molecular markers that improve the risk stratification of these patients are needed. In the past few years, we have witnessed an unprecedented molecular characterization of PPGL, which led to the emergence of promising candidate biomarkers predictive of metastatic behavior. Here, we briefly discuss these breakthroughs and provide some insights for the prospective implementation of molecular markers of metastatic PPGL in the clinical setting in years to come.