Papillary Thyroid Carcinoma with Retropharyngeal Node Metastasis Demonstrating Negative I-131 but Positive FDG Uptake on PET/CT / 대한내분비외과학회지

ABSTRACT

Papillary thyroid carcinoma (PTC) is commonly accompanied by cervical lymph node metastasis, whereas metastases to the retropharyngeal lymph nodes (RPN) are rare. Radioactive iodine (RAI) ablation is recommended for detection and treatment of differentiated thyroid carcinoma (DTC). However, in some cases of iodine-negative DTC, F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) can aid in detection of additional lesions. We report on a patient with PTC who had retropharyngeal node involvement with iodine-negative features and low thyroglobulin level at the time of diagnosis but with metastasis identified on FDG PET/CT.