Cavernous sinus metastasis from thyroid papillary adenocarcinoma.

We report here an extremely rare case of cavernous sinus metastasis from thyroid papillary adenocarcinoma presenting long after initial diagnosis. A 41-year-old patient presented with a cavernous sinus tumor causing progressive diplopia 10 years after treatment for a papillary adenocarcinoma of the thyroid. After 5 years of close observation, subarachnoid hemorrhage developed from the cavernous sinus tumor extending to the cerebellopontine angle, at which point the patient underwent surgical removal of the tumor followed by gamma knife radiosurgery. The pathological diagnosis was papillary adenocarcinoma, indicating the distant metastasis from the thyroid. This case illustrates the unique event of a cavernous sinus metastasis long after initial treatment of the primary cancer.