A Discrepancy between 131 I-Metaiodobenzylguanidine ( 131 I-MIBG) Scintigraphy and 18 F-FDG PET/CT after 131 I-MIBG Therapy in a Patient with Recurred Malignant Pheochromocytoma

A 59-year-old woman who was diagnosed with malignant pheochromocytoma underwent -fluorodeoxyglucose positron emission tomography/computed tomography (-FDG PET/CT). She had undergone left adrenalectomy for pheochromocytoma 4 years previously. Recent multiple metastatic pulmonary nodules were noted on the chest X-ray. After treatment with -metaiodobenzylguanidine (-MIBG) with 7.4 GBq, post-therapy -MIBG scintigraphy depicted multiple distant metastases including lung, liver, abdominal para-aortic and mesenteric lymph nodes. -FDG PET/CT also depicted multiple metastases in lung, liver, and abdominal para-aortic lymph nodes, but some lesions were not shown. In this case, -MIBG scintigraphy found additional lesions in metastatic malignant pheochromocytoma.