[Strategy for the biochemical study of pheochromocytoma].

The measurement of urinary methoxyamines (metadrenaline and normetadrenaline) by a method as selective as possible, is the best test for the biochemical diagnosis of pheochromocytoma. Its diagnostic reliability (99,5 p. 100) is much higher than that of urinary catecholamines (59 p. 100) or VMA (38 p. 100) or plasma catecholamine measurement. Drug interference is reduced. Two or three tests on consecutive days are adequate to establish the diagnostic, even in intermittent secreting tumours.