Skull Base Metastasis from Follicular Thyroid Carcinoma: A Case Report and Review of the Literature

Metastasis to the skull base is rare but occurs most frequently with breast and prostate cancer. Suspicion for skull base metastasis should be elevated in patients with a history of cancer and unexpected ipsilateral cranial nerve findings. In this case report, we present a highly aggressive case of poorly differentiated follicular thyroid carcinoma with the unanticipated finding of metastatic spread the skull base. This case is unique from others given the extensive involvement of the pelvis, larynx, and aggressive infiltration of multiple skull base sites including the cavernous sinus, Meckel’s Cave, foramen ovale, and the floor of the right middle fossa. We conclude that skull base metastasis should be on the differential diagnosis for a patient with a history of aggressive thyroid cancer and new pathologic ipsilateral cranial nerve physical exam findings.