Résumé
A paraganglioma that arises from the Retroperitoneum, mediastinum is an extra-adrenal form of pheochromcytoma. Extra-adrenal pheochromocytomas can occur at any site in the abdomen where chromaffin tissue is located and have been found in the paravertebral ganglia, the organ of Zuckerkandl, and the urinary bladder. An extra-adrenal pheochromocytomas can arise from a collection of para-aortic, paraganglion cells located at the origin of the inferior mesenteric artery, This collection of paraganglia was first described in fetuses by Zuckerkandl in 1901 and has subsequently been referred to as the organ of Zuckerkandl. Extra-adrenal pheochromocytoma generally secrete norepinephrine, not epinephrine, because there is an absence of the enzyme phenyl- ethanolamine-N-methyl transferase. Therefore symptoms are related to the production of norepinephrine. Extra-adrenal pheochromocytomas pursue a more aggressive course than their adrenal counterparts. It was found to metastasize in approximately 20% to 40% of cases, compared with only a 2% to 10% rate of metastasis in all adrenal tumors. We report on a three case of paragangliomas that had a functional and non-functional paraganglioma of the organ of Zuckerkandl and a case of a non-functional paraganglioma of the posterior mediastinum.