[Malignant pheochromocytoma. A case report and comments on a rare pathology]

Pheochromocytomas and functioning paragangliomas are rare tumors arising from the primitive neural crest, and found in the adrenal medulla or elsewhere within the sympathetic paraganglion axis. Clinical symptoms are related to catecholamine production or less frequently to dopamine or other neuropeptides secretion. Malignant pheochromocytomas are very rare tumors comprising between 5-35%, but this value is uncertain because the usual criteria for malignancy, such as mitotic activity, nuclear pleomorphism, are not suitable to discern benign from malignant pheochromocytomas. A specific diagnosis of malignancy requires evidence of invasion of the adjacent organs and the occurrence of metastases. Personal experience is presented with 92 patients affected by: adrenal pheochromocytomas (51 cases), cervical paragangliomas (32 cases), and extra-adrenal paragangliomas (9 cases). Malignant forms were observed in a 23-year-old young woman affected by malignant pheochromocytoma with lymphatic para-aortic metastases (1.9%), and in 2 patients affected by cervical paragangliomas (1 CBT, 1 VBT) with lymph nodal metastases. Careful follow-up of all patients with measurement of the urinary catecholamine is necessary to detect metachronous neoplasm and later metastases, identified with RMN and 131I-MIBG scintiscan.