High prevalence of dopamine excess in patients with head and neck paragangliomas
Anouk van der Horst-Schrivers, Thamara Osinga, Ido Kema & Robin Dullaart
Objective: We determined the prevalence of abnormal secretion of dopamine and other catecholamines in relation to clinical symptoms in patients with head and neck paragangliomas (PGL). The association of catecholamine production with nuclear imaging was also assessed.
Methods: Thirty-six consecutive patients with head and neck PGLs, who were referred for follow-up and/or treatment between 1993 and 2009, were included. Clinical symptoms, dopamine excess (urinary 3-methoxytyramine (3-MT) or dopamine and/or plasma dopamine or 3-MT) and (nor)epinephrine excess (urinary (nor)metanephrine excess) as well as 111In-octreotide and 123I-metaiodobenzylguanide (MIBG) scintigraphy were documented.
Results: Dopamine excess attributable to head and neck PGLs was found in 7 patients (19.7%). Marginally elevated urinary (nor)metanephrine excretion was present in 6 patients (16.7%); one additional patient had normetanephrine excess due to adrenal pheochromocytoma. Clinical symptoms and blood pressure were not significantly different in patients with and without dopamine excess. 111In-octreotide was positive in 94.3% of patients. 123I-MIBG uptake in the head and neck region (36.1%) was associated with dopamine excess (P=0.03).
Conclusion: Dopamine excess is present in a considerable percentage of patients with head and neck PGLs, and is associated with functional imaging of the lesions. Abnormal dopamine secretion seems unrelated to clinical symptoms in the majority of patients. In view of potentially adverse clinical consequences, we propose routine assessment of abnormal secretion of dopamine and other catecholamines in PGL management. Serial measurement of dopamine or its metabolites could be useful in the follow-up of PGL patients.