Follicular adenocarcinoma of the thyroid in the maxillary sinus.

No reports of metastatic thyroid carcinoma in the maxillary, ethmoid, or sphenoid sinuses can be found in the literature. A woman with severe posterior epistaxis was examined recently. She had undergone a partial lobectomy for a thyroid tumor 16 years previously. Hemorrhagic thyroid tissue was in the maxillary sinus. The results of subsequent examinations indicated thyroid deposits in the lung and spine. The patient received radioactive iodine, 100 MCi. Her lung and spine deposits lysed, and she experienced no further epistaxis. Thyroid carcinoma's ability to metastasize to a paranasal sinus is documented here. Epistaxis after a thyroidectomy for cancer now must be considered an unusual clinical manifestation of metastatic spread, unless otherwise proved. The differential diagnosis of epistaxis must now include thyroid carcinoma metastatic to the sinonasal tract.