Occult functioning vagal paraganglioma in the infrahyoid carotid sheath.

Paragangliomas are highly vascular tumors that arise from chief cells in extra-adrenal paraganglia of the autonomic nervous system. Vagal paragangliomas occur along the vagal nerve, usually located in the rostral portion of the vagus nerve in the vicinity of the gangliom nodosum. Actively functional vagal paragangliomas are rare. We report a patient with functioning vagal paraganglioma located in the infrahyoid carotid sheath. The patient had no history of hypertension and catecholamines were not measured before surgery. The findings of diagnostic imaging workup, including computed tomography, ultrasonography and magnetic resonance, were suggestive of paraganglioma. The blood pressure and pulse rates increased sharply intraoperatively during tumor manipulation, together with spikes in noradrenaline and dopamine. The tumor was removed with successful preservation of the vagus nerve trunk. The blood catecholamine levels returned to normal immediately after surgery. Head and neck surgeons should be aware of occult functioning paragangliomas and patients with such tumors should undergo full hormonal assessment.