Use of plasma catecholamine values in diagnosing pheochromocytoma and neuroblastoma

The diagnosis in two cases of neural crest tumours was confirmed by the measurement of concentration of plasma catecholamines. A histamine provocative test monitored by values of plasma catecholamines provided support for a diagnosis of pheochromocytoma in a patient with normal blood pressure and elevated values of urinary amines. In the second case the presence of a ganglioneuroblastoma secreting abnormal amounts of catecholamines was detected by plasma epinephrine and norepinephrine measurements when values of urinary free catecholamines were normal.