A 17-year-old female had been complaining of a headache for 6 years. She presented severe hypertension (200/138 mmHg) on admission. CT showed a hypervascular tumor behind the urinary bladder and a swelling of the right internal obturator node. Intense FDG uptakes were identified in the both lesions. High FDG accumulation was also observed in the brown adipose tissue (BAT) throughout the patient's body, and intense contrast enhancement was found in the BAT on CT. The diagnosis was a malignant paraganglioma with obturator node metastasis. The post-surgery FDG-PET/ CT examination revealed that the FDG accumulations in the BAT had completely disappeared.