Histopathology revealed papillary thyroid cancer in the index nodule, as well as 2 other foci of papillary thyroid cancer.<h4>Discussion</h4>FAT1 mutation has been previously associated with head and neck squamous cell carcinoma but has not been reported in the context of papillary thyroid cancer.<h4>Conclusion</h4>FAT1 gene variation may be a novel mutation associated with papillary thyroid cancer. This evidence concerns the gene FAT1 and head and neck squamous cell carcinoma.