OCCULT FOLLICULAR CARCINOMA METASTASIZING TO THE SINONASAL TRACT

We report a 34-year-old woman with a clinically occult primary carcino ma of the thyroid metastasizing to the sinonasal tract. The metastasis showed intensive vascularization and involved the nose, the maxillary , ethmoid and sphenoid sinuses, extending to the intracranial cavity. After embolization, the lesion was removed and histopathologically dia gnosed as follicular carcinoma of the thyroid. A subsequent total thyr oidectomy revealed an,X-mm primary lesion within the left lobe. Thyroi d metastases, although rare, need to be considered in the differential diagnosis of hypervascular tumors in the sinonasal tract.