MIBG superscan of metastatic paraganglioma occurring with neurofibromatosis type 1.

A Tc MDP bone superscan occurs when osseous activity is extremely intense and genitourinary and soft tissue activity is not identified. A similar phenomenon has been described with metaiodobenzylguanidine (MIBG) in metastatic pheochromocytoma and neuroblastoma. We present a case of metastatic paraganglioma resulting in an MIBG superscan. Neuroendocrine bone metastasis alters the biodistribution of MIBG such that the liver, heart, and urinary bladder are not well visualized. Our case occurred in association with neurofibromatosis type 1 and in the absence of an identified primary tumor.