Lymph Node Metastasis from Tall-Cell Thyroid Cancer Negative on 18F-FDG PET/CT and Detected by 18F-Choline PET/CT

摘要

A 77-year-old woman underwent thyroidectomy and I-131 remnant ablation for tall-cell differentiated cancer (DTC) of the left lobe. Detectable Tg levels (4.1 mu g/L) under TSH suppression, with undetectable serum Tg-antibody levels, prompted neck ultrasonography, which revealed a lymph node in the left laterocervical region and in the right retroclavicular region. F-18-FDG PET/CT showed uptake by the left lymph node. F-18-choline PET/CT showed increased uptake by both lymph nodes. Histopathology revealed DTC solid metastasis in the left lymph node and solid and cystic metastasis in the right one. F-18-choline PET/CT can locate virulent DTC recurrence, thereby increasing F-18-FDG PET/CT information.