Pheochromocytoma: When to search a germline defect?

With advances in our understanding of the genetics of pheochromocytomas and paragangliomas (PPGL), the answer to the question 'Should we search for a germline defect in patients diagnosed with PPGL?' has changed considerably since the end of the last century, when PPGL was thought to be inherited in only 10% of cases, because we now know that about 40% of patients carry a germline mutation in one PPGL susceptibility gene. PPGL is now considered to be the most highly heritable neuroendocrine tumour, with more than 15 susceptibility genes identified, and current guidelines recommend genetic testing during initial tests on PPGL patients. This genetic testing is routinely carried out by next-generation sequencing methods, making it possible to genotype a large number of susceptibility genes in a single analysis. Positive results for any of the known susceptibility genes are an indication for specific follow-up of the inherited disease and for the organization of predictive genetic testing in the patient's relatives. The development of precision medicine for PPGL, based on the molecular profile of the tumor, should become possible in the near future.