Demonstration of thyroidal metastasis from lung cancer by F-18 FDG PET scan.

A case is presented of detection of a secondary thyroid cancer arising from a pulmonary adenocarcinoma by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET). The need to investigate thyroidal hypermetabolic foci detected incidentally on PET scans is well established so as not to miss a primary thyroid cancer. However, as our case illustrates, the possibility of metastatic thyroid cancer, even though less common, should be considered.