Use of fusion images of I-131 metaiodobenzylguanidine, SPECT, and magneticresonance studies to identify a malignant pheochromocytoma

Pheochromocytoma is a chromaffin tumor in which 10% are extra-adrenal and 1 0% are malignant, I-131 metaiodobenzylguanidine (MIBG) scintigraphy has an important role in the identification of these tumors and investigation of m etastatic lesions. The authors describe a 36-year-old woman who underwent r esection of a malignant left adrenal pheochromocytoma who was thought to ha ve metastases in the liver and para-aortic lymph nodes. Fusion images of I- 131 MIBG SPECT and magnetic resonance studies were obtained to properly ide ntify the metastatic lesions. These fusion images helped greatly in subsequ ent surgery.