[Functioning paraganglioma].

Pheochromocytomas and functioning paragangliomas are rare tumors arising from indifferent cells of the primitive neural crest. These tumors produce clinical symptoms (pheochromocytoma syndrome) related to catecholamine production. The pheochromocytoma syndrome, constituted by arterial hypertension, headache and sweating, is due in 80% of cases to adrenal pheochromocytomas and only in 20% of cases is due to extra-adrenal secreting paragangliomas. The diffused localization of the Paraganglion System and the common embryologic origin, can explain the occasional identification of multicentric tumors (10%), and the association with multiple endocrine neoplasms (MEN), especially in familial occurrence. Careful follow-up of patients, in order to detect the later development of multicentric or metachronous neoplasms is necessary. The Authors present their experience with 80 patients affected by neoplasms involving the adrenal medulla and the multicentric paraganglion system, surgically treated during the last 25 years. Eight patients (10%) were affected by functioning extra-adrenal paragangliomas: 7 patients (87.5%) had solitary extra-adrenal tumors (6 abdominal and 1 thoracic) with a classic pheochromocytoma syndrome, and 1 patient (12.5%) had a double asymptomatic abdominal paraganglioma.