Abstract
BACKGROUND: Metastatic follicular thyroid carcinoma to the central nervous system (CNS), including the skull and dura, is exceedingly rare. OBSERVATIONS: The authors present the case of a gigantic, intraosseous, dural-based follicular thyroid carcinoma, highlighting the operative strategy for this mass. They also provide a literature review of CNS metastases of differentiated thyroid carcinoma. LESSONS: Although follicular thyroid carcinoma rarely metastasizes to the CNS, it should be included in the differential diagnosis of hypervascular intraosseous skull lesions, even in the absence of disseminated metastatic disease. The authors illustrate key operative steps in managing the tumor's hypervascularity, extracranial extension, and posterior sagittal sinus invasion, as well as unintended sequelae from ligating the seemingly occluded anterior and middle third of the superior sagittal sinus in large tumors. https://thejns.org/doi/10.3171/CASE24550.