Paragangliomas

Paragangliomas-A Decade of Clinical Experience, Somasundar, Journal of Surgical Oncology 74:286 (2000)

Paragangliomas arise from neuroendocrine cells of the autonomic nervous system.

Here idenitified 14 patients with paragangliomas at WVU from 1986-1996. Nine had paragangliomas in the head and neck region. Nine tumors originated from the carotid body, 3 from glomus vagale and 2 from glomus tympanicum. There were 14 tumors in 9 patients. --- had metastasis to the adjacent regional lymph nodes and 1 had metastasis to the thoracic vertebrae. Also, both of these arose from the carotid body.

These are rare tumors causing considerable difficulty in diagnosis and treatment. Although most are benign, about 10% of those in the carotid body recur. The malignant potential is determined by local invasion and distant metastasis.

Carotid bodies and related paraganglia have been described a homeostatic role by sensing fluctuations in blood Ph and oxygen tension. Most common site is at the carotid bifurcation. They are asymptomatic initially, however, with progression they can invade the skull base and affect cranial nerves. Most frequent presenting symptom is that of palpable neck mass in carotid paraganglioma, located below the angle of the jaw and deep to the sternomastoid muscle, that either the patient or the family doctor noticed on routine physical examination. The mass is frequently pulsatile and bruit can be auscultated. Cranial nerve deficits may be seen with larger tumors. Deficits of cranial nerves 9 and 10 are most commonly seen in the cranial nerves. 7, 8, 11, and 12 can also be affected. None of our patients presented with cranial nerve palsies.

MRI and CT scan showed a typical carotid body tumor located at bifurcation of the cervical, and carotid artery. The characteristic and almost pathognomic finding of flow voids within the lesion on spin echo, MRI or flow augmentation on gradient echo sequences represents the large blood vessels within the carotid body tumor, a finding usually not present in other histologic tumor types present in this location. Blood supplies in the carotid bodies is by multiple tiny feeding vessels from the proximal internal and external carotid arteries and from the crotch between these arteries. Because the carotid body lies on the posterior medial aspect of the internal carotid artery in the area of the bulb, this may be the most difficulty area to resect and is approached last. If necessary, the external carotid artery is ligated to permit rotation or rolling of the internal and common carotid arteries.