High-altitude paragangliomas diagnostic and therapeutic considerations.

Forty-one cervical paragangliomas that occurred in 40 patients born and living in Mexico City, Mexico, were studied. Tumors were most common in women (38/40); were unilateral (39/40), without a side preference; were of the nonhereditary type; and were not malignant. Tumor imaging with radionucleaide angiographic scanning was noninvasive, innocuous, and reliable for screening, whereas selective carotid angiography allowed for definitive diagnosis and clinical stratification of patients. Surgical resection was performed in 29 patients; in 23 cases, en bloc resection was accomplished without a vascular compromise, whereas in 4 patients, a portion of the external carotid artery had to be ligated and resected. Two other patients required a vascular graft to restore blood flow to the internal carotid. Seven patients had postoperative transient cranial nerve palsies, and one had an incomplete hemiplegia. Permanent nerve damage occurred in seven patients. It was concluded that high-altitude paragangliomas are hyperplastic growths that result from adaptation to hypoxia. They are rarely true neoplasm and, in general, are not associated with functional loss. In view of this and of the high morbidity rate associated with surgical removal, it was recommended that these patients be referred to research centers where efforts toward the elucidation of the etiology and pathophysiology of these tumors can be carried out. Surgery should be reserved for symptomatic cases or cases in which the diagnosis remains in doubt. The decision to operate must weigh the following factors: The tumor's benign nature, its slow growth rate, the technical difficulties associated with its resection, the high postoperative morbidity rate, and the general condition of the patient.