Dopamine and Dopa Urinary Excretion in Patients with Pheochromocytoma–Diagnostic Implications

Abstract

Pheochromocytoma, a potentially life-threatening disease, is a rare cause of hypertension. Most pheochromocytomas secrete excessive amounts of noradrenaline and adrenaline. It has been suggested by some authors that high circulating levels of dopamine and the catecholamine precursor dihydroxyphenylalanine (dopa) are more often associated with malignant rather than benign pheochromocytomas. Therefore the aim of this study was to evaluate urinary excretion of dopamine and dopa in patients with pheochromocytoma and to determine their role as a potential marker for malignancy of the tumour. We retrospectively analysed 120 consecutive patients (mean age 41 +/- 12 years) with histopathologically confirmed pheochromocytomas. All subjects were divided as follows: group 1 included patients with both elevated and normal dopamine urinary excretion; group 2 was characterized by increased and normal dopa urinary excretion. Dopamine urinary excretion was increased in all patients with malignant pheochromocytoma, but higher levels were also observed in some patients with a benign tumour included in group 1. Urinary excretion of dopa was in the normal range in all subjects with malignant pheochromocytoma. The results indicate that in some pheochromocytoma patients excessive dopamine excretion may point to malignant tumour, but is not a discriminating marker for malignancy in the whole studied group.

Increased Urinary Excretion of 3-Methoxytyramine in Patients with Head and Neck Paragangliomas

“…Although dopamine-secreting paragangliomas are often asymptomatic (9), excessive excretion of dopamine can cause complaints of nausea, vomiting, flushing, and orthostatic hypotension (18,19). We observed that the clinical manifestations in patients with increased 3-methoxytyramine excretion were different compared with those in patients with normal excretion of 3-methoxytyramine.…”

Gene Expression Profiling of Benign and Malignant Pheochromocytoma

“…16,17 This may reflect predominant development of malignant pheochromocytomas from neural crest progenitors arrested in an early stage of development with a malignancy-prone lineage able to populate both adrenal and extra-adrenal sites of chromaffin tissue. The matching of gene expression profiles in neural crest progenitors with those in different groups of pheochromocytomas and mechanistic studies linking these progenitors to effects of specific genes provides possible approaches to test the foregoing hypotheses.…”

Malignant pheochromocytoma: current status and initiatives for future progress

“…As reviewed by David Goldstein, high plasma and urinary levels of dihydroxyphenylalanine and dopamine, the immediate precursors of norepinephrine, are biochemical hallmarks that may characterize malignant pheochromocytoma (Anton et al 1967, Goldstein et al 1986, John et al 1999, Januszewicz et al 2001, van der Harst et al 2002. While suggestive of a dedifferentiated state that might be associated with malignancy, these markers do not, however, accurately discriminate benign from malignant pheochromocytomas.…”