Metastatic medullary thyroid cancer: localization with iodine-131 metaiodobenzylguanidine.

A patient in whom metastatic medullary thyroid cancer was diagnosed underwent a scintigraphic examination using [131I]MIBG. Multiple hot lesions and diffuse hepatic uptake were noted corresponding to bone and liver metastases. Iodine-131 MIBG may prove to be useful for scintigraphic localization and for the treatment of medullary thyroid cancer as in pheochromocytoma and neuroblastoma.