Update on the diagnosis of the pheochromocytoma.

Pheochromocytoma is a rare neuroendocrine tumour that develops from chromaffin cells in the adrenal medulla and is characterised by the excessive production of catecholamines and their metabolites. Diagnostic confirmation is performed by detecting elevated levels of catecholamines and/or their metabolites in plasma or 24-h urine. In the case of moderate elevations of normetanephrine, the clonidine suppression test may be useful to differentiate between endogenous hypersecretion and false positive results. Once the biochemical diagnosis is performed, the tumour localisation is carried out using imaging techniques and sometimes with nuclear medicine imaging tests. Furthermore, in all patients with pheochromocytomas it is recommended to perform a genetic study to identify hereditary disorders that may be present in more than 30% of cases and to perform a cardiological evaluation to rule out the presence of cardiovascular involvement secondary to the catecholamine hypersecretion.