Metastasis of follicular thyroid carcinoma to the maxillary sinus.

Thyroid carcinoma metastatic to the paranasal sinuses is extremely rare. We report a case of follicular thyroid carcinoma metastatic to the right maxillary sinus, with extension into the right side of the hard palate in a young lady. A radioactive iodine-131 (I-131) scan post total thyroidectomy revealed 0.8% uptake in the neck; the whole body scan revealed a functioning metastasis in the region of the right maxillary antrum. Pathological confirmation of metastasis was done by correlating the fine needle aspirate cytology with the thyroidectomy histology. The patient initially received 40 Gy of external beam radiotherapy, subsequently, she received 110 millicuries of I-131, followed by 50 millicuries 6 months later. She continues to be on follow-up on Eltroxin™ suppression and has remained disease free for the past 4 ½ years.