Bilateral Choroid Plexus Metastasis from Papillary Thyroid Carcinoma: Case Report and Review of the Literature.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. It has an indolent clinical course and favorable prognosis. Brain metastasis is uncommon and complicates about 0.1%-5% of PTCs. Metastasis to the choroid plexus of the lateral ventricles has been reported in 7 cases of thyroid malignancies, all of which were unilateral.

METHODS: We report a case of a 52-year-old woman with a history of PTC who presented with severe headache, nausea and vomiting, right hemiparesis, and speech disturbance. Imaging studies depicted lesions in both lateral ventricles.

RESULTS: The patient underwent microsurgical tumor resection. Histopathologic examination revealed choroid plexus metastasis from PTC.

CONCLUSIONS: Metastases to the choroid plexus from extracranial tumors are very rare, with only a few cases reported thus far. A demographic analysis of these cases suggests there may be a tropism of some extracranial carcinomas, such as renal cell carcinoma, for choroid plexus, especially in the lateral ventricles. We report the eighth case of choroid plexus metastasis, but it is the first bilateral one arising from thyroid cancer.