Pinar Akkus Gunduz, Mahsun Cidemal, Asena Gokcay Canpolat, Cigdem Soydal
A 70-year-old woman with endometrial carcinoma underwent 18F-FDG and 18F-FES PET/CT for pretreatment evaluation. Both studies demonstrated focal uptake in a nodule at the inferior pole of the left thyroid lobe. Ultrasonography revealed a TI-RADS 3 nodule, and fine-needle aspiration cytology showed atypia of undetermined significance. Total thyroidectomy was performed, and histopathology revealed a 20-mm noninvasive encapsulated classic papillary thyroid carcinoma. Estrogen receptor (ER) immunohistochemistry was unavailable; therefore, the relationship between 18F-FES uptake and ER expression could not be assessed. The patient subsequently received 100 mCi of radioactive iodine.