[New aspects and possibilities in the diagnosis of pheochromocytoma]. / Nové názory a moznosti v diagnostice feochromocytomu.

ABSTRACT

Pheochromocytoma is still a dangerous disease which is often difficult to diagnose. Evidence of the wide spectrum of its clinical picture was found in a group of 13 patients who were examined in the last 5 years. Drawing on their experience, the authors evolved a scheme of diagnostic examination. The primary biochemical examination involves the determination of urinary excretion of free catecholamines adrenaline, noradrenaline and dopamine simultaneously with their methylated metabolites metanephrine and normetanephrine, which help to make a more exact diagnosis in cases where the results of free catecholamines are not clear. Patients with pheochromocytoma lack diurnal rhythm of catecholamine excretion and thus the collection is made twice - by day and night. The determination of plasma catecholamines provides additional information. Only half the patients were found to have the level of vanillylmandelic acid increased. A significantly increased dopamine excretion points to the malignant form of the disease. The localization is established with the aid of computed tomography and, if needed, also by the determination of plasma catecholamines through selective cavae sampling. The final step serving to verify the diagnosis involves analysis of catecholamines in tumour tissue.