Unusual thyroid carcinoma metastasis in paranasal sinuses and parapharyngeal space

The prevalence of follicular cell-derived thyroid carcinoma with an unusual pattern in its metastatic spread is relatively unknown, and therefore its clinicopathological characteristics are not well defined and represent uncertainty in diagnosis and treatment. In this report, two cases of metastasis in the paranasal sinuses and one of metastasis in the parapharyngeal space are described. In the first case, given the extension of the lesion to the cavernous sinus, surgical resection was not possible and external radiotherapy management was determined. However, the patient died of COVID-19. In the second case, the patient underwent endoscopic release of the left maxillary nerve and partial resection of the tumor as a palliative measure, clinical improvement was observed, and he subsequently received 30Gy external radiotherapy. The third case was managed surgically using a minimally invasive approach using robotic transoral surgery, which was successful. Metastasis in the paranasal sinuses and parapharyngeal space due to differentiated thyroid carcinoma represents an unusual scenario. Its characterization and management will always be a challenge, but new minimally invasive techniques play an increasingly promising role. © 2022 EDIZIONI MINERVA MEDICA.