Comparative 18 F-FDG PET/CT and FAP-targeted PET/CT Findings in Parotid Warthin Tumor.

Warthin tumor is the second most common benign parotid neoplasm and often shows marked uptake on 18 F-FDG PET/CT, frequently mimicking malignancy. In contrast, its imaging characteristics on fibroblast activation protein (FAP)-targeted PET/CT remain insufficiently defined. We report 2 cases of parotid Warthin tumors that demonstrated marked FDG uptake but absent or minimal uptake on FAP-targeted PET/CT using 68 Ga-FAPI-04 and 68 Ga-FAP-2286. This discordant imaging pattern suggests that FAP-targeted PET/CT may aid in distinguishing Warthin tumor from malignant lesions.