[Malignant pheochromocytomas. Apropos of a case with multiple metastatic localizations]

We are reporting a case of malignant pheochromocytoma surgically treated initially for an isolated left pararenal localization, and which recurred several years later accompanied with numerous metastases. Despite of a treatment with Iodine 131 MIBG, the evolution was rapidly fatal with a picture of cardiac failure. This cardiac involvement would be linked to a myocarditis directly secondary to the catecholamines and causing a marked increase of the free fatty acids concentration in the heart tissue. In reference to this case, all the data which may tend to suspect the malignant nature of a pheochromocytoma, present in 10 p. cent of the cases, are successively reviewed. There is no clinical specificity. The presence of a mixed secretion with marked urinary dopamine secretion, would not present, for all authors, the same criteria of specificity. Thoraco-abdominal scan and scintigraphy with iodine 131 MIBG are the two tests permitting to demonstrate, with a great sensitivity and specificity, an extra-adrenal localization, which is the best argument in favor of a malignancy since 30 to 40 p. cent of extra-adrenal pheochromocytomas are malignant, more especially as the metastases are located in areas where there are no embryonic remnants of tissues containing chromaffin cells. This permits to appreciate the difference between a non-malignant multicentric pheochromocytoma and a malignant pheochromocytoma. The ideal treatment of a malignant pheochromocytoma rests on surgery under the condition that there are ony one or two metastases. This procedure is preceded by a sodium nitroprusside preparation and followed with an alpha-blockers treatment. In case of multiple metastases, the therapeutic use of iodine 131 MIBG seems to be a tempting alternative.