Giant metastasis to the choroid plexus of papillary thyroid cancer: case report and review of the literature.

Metastases to the choroid plexus are extremely rare, accounting for only 1% of brain metastasis cases. Among intraventricular tumors, the most frequent are papillary carcinomas, meningiomas, and papilloma, with rare metastatic lesions accounting for only 6% of all intraventricular lesions. We report the case of a patient with a giant metastatic lesion of papillary thyroid cancer with intratumorally hemorrhage in the choroid plexus of the left lateral ventricle, which was treated urgently with subtotal resection of the lesion and subsequent adjuvant treatment with radiotherapy. To date, we report the 10th case of primary choroid plexus metastasis of the thyroid.