The term paraganglia best defines the spread in the body of clusters of cel
ls with histological and cytochemical characteristics of neuroendocrine cel
ls originating from the neural crest. with either sympathetic or parasympat
hetic function. Carotid body hyperplasia is associated with long-standing h
ypoxia as in native inhabitants in high altitude or in patients with chroni
c pneumonopathies. while carotid body paraganglioma is a rare parasympathet
ic tumor with significant morbidity. Tumor extension per se, associated cra
nial nerve involvement, and the estimated 3-10% malignant potential. partic
ularly at a young: age, make early diagnosis and treatment of carotid body
paraganglioma mandatory. Biopsy should be avoided, because of the accompany
ing incidence of hemorrhage, while it is essential in all cases to investig
ate both sides of the neck to exclude bilateral tumors. The modalities of t
herapy include preoperative embolization, preoperative and postoperative ra
diation with ambiguous results of both, and complete surgical removal which
constitutes the definite therapy. The current stroke rate is less than 5%.
The histological appearance of a carotid body paraganglioma is not a relia
ble guide to its propensity for malignant behavior and recurrences are most
likely to appear in patients who have multiple paragangliomas or a family
history of carotid body paraganglioma.