Paragangliomas of the head and neck.

Paragangliomas are neuroendocrine tumors derived from the extra-adrenal paraganglia of the autonomic nervous system. Within the head and neck, they are generally defined and named according to their site of origin, and may be found frequently neighboring vascular structures. Physiologic activity is rare in these neoplasms and they may exhibit patterns of inheritance which predispose their occurrence in families, often with multicentricity. These tumors generally exhibit a slow rate of growth, most often presenting asymptomatically as a space occupying mass lesion noted clinically or radiographically. The most common paraganglioma of the head and neck is the carotid body tumor followed by the jugulo-tympanic and vagal varieties. Other rare sites where this tumor may occur include; the larynx, sinonasal chambers and orbit. Diagnosis is generally made through a combination of clinical findings and radiographic studies. Magnetic resonance represents the most important imaging modality for the evaluation and characterization of suspected head and neck paraganglioma. Definitive management for these lesions should be carefully considered in relation to both tumor and patient-oriented factors, especially in regard to the potential morbidity of treatment. Surgery and radiation therapy represent the main treatment modalities for paraganglioma. The selection of treatment depends on the size, location, and biologic activity of the tumor as well as the overall fitness of the patient. Although radiotherapy may be effective in arresting growth of these tumors, rarely is the neoplasm eliminated without surgical resection. Surgery may be associated with significant morbidity, primarily as a consequence of incurring major cranial nerve injury. Patient selection (relative to age and medical condition) should be carefully considered prior to recommending aggressive surgery for paragangliomas of head and neck, especially in those patients at risk for disabling surgical morbidity.