Ectopic Papillary Thyroid Carcinoma Mimicking Esophageal Cancer in FDG PET

Ectopic papillary thyroid carcinoma (PTC) usually occurs along the cervical midline and was barely reported in FDG PET studies. We present a rare case of ectopic PTC within the esophagus with focal FDG activity on FDG PET in a 43-year-old woman who was previously diagnosed as having esophageal cancer based on the endoscopy and PET findings. Surgical pathology revealed the presence of PTC lesion within the muscular layer of the esophagus. Combining this with the negative imaging and laboratory results suggesting a normal thyroid gland led to a diagnosis of primary ectopic PTC.