[Non-hypertensive pheochromocytoma. Description of 2 clinical cases].

: The Authors describe two cases on non hypertensive ppheochromocytoma, one malignant and one benign. These types of heochromocytoma are generally considered to be nonsecreting tumours, tumours characterised by long periods of inactivity. More recent studies have evidenced, however, that at least in a certain percentage of cases this type of tumour can secrete catecholamicen precursors or metabolites having low activity and hence incapable of causing appreciable pressure alterations. Diagnosis of these forms is always difficult and cannot be done purely on the basis of assay of the urinary catecholamines, but also requires assay of VMA, HVA, metadrenaline and Normetadrenaline. Treatment of this pheochromocytoma is surgical and resolves the hypertensive symptoms in 80% of the benign forms. On the other hand, it rarely leads to cure in the malignant types.