[Specific scintigraphy in pheochromocytoma].

In 5 patients with pheochromocytoma and 1 patient with a pheochromoblastoma, 131I-meta-iodobenzylguanidine was used to localize hyperfunktioning adrenergic tissue. Except in one patient, a correct localization of the tumors was obtained. Three patients had an intraadrenal pheochromocytoma of the left adrenal gland, 1 patient a retropancreatic pheochromoblastoma and 1 patient multilocular pheochromocytoma with tumors in both renal hili, in the supraclavicular region and in the bones. In one patient with a pheochromocytoma of the right adrenal, no clearcut visualization of the tumor could be observed. In this patient, in contrast to the other examinations, a specific activity of 2 mCi/mg benzylguanidine was used (0.2 mCi/mg benzylguanidine in the other patients). Thus, the amount of benzylguanidine given for each scan was 10fold higher in the patients with a correct localization. The present results document the claim that scintigraphy with 131I-benzylguanidine is a safe and reliable method of detecting both benign and malignant adrenal and extra-adrenal pheochromocytoma. To separate the pheochromocytoma from the adjacent tissue, additional computed tomography should be performed.