[Catecholamines in the cardiovascular expression of pheochromocytoma. II--Study of free urinary catecholamines in 14 pheochromocytomas. Classification of pheochromocytomas according to type of secretion]

Abstract

Studies were conducted in 14 patients with pheochromocytoma over a 3-year period. Circumstances of detection of these tumors varied greatly and were sometimes misleading, hypertension being an inconstant finding in the clinical history and was not always the predominant feature. Biologic exploration involved assay of excretion of free urinary noradrenaline (NA), adrenaline (AD) and dopamine (DA) using a HPLC technique as well as assay of total methoxy derivatives and urinary vanilmandelic acid. Validity of each assay in the diagnosis of pheochromocytoma could be evaluated and only the total free methoxy derivatives gave false negative results. Hormonal secretion of pheochromocytoma is often mixed, but sometimes predominant or exclusive for a single catecholamine. Relative increases of the different catecholamines, evaluated from the ratios DA/NA and DA/NA + AD, are an important factor since a relation exists between blood pressure induced symptomatology and equilibrium between hypotensive hormone (DA) and pressor amines (NA + AD); 3 types of pheochromocytoma can be described: NA-induced with paroxysmal or permanent hypertension but without typical metabolic and cardiac disorders, and with a very reduced DA/NA + AD ratio during hypertensive crises; AD-induced without permanent hypertension but with a mainly orthostatic hypotension and episodes of cardiovascular collapse following hypertensive attacks and with an AD/NA ratio greater than 1; finally the DA-induced lesion in which hypertension is never associated and manifestations are misleading and atypical with an elevated DA/NA + AD ratio.