Metastatic Medullary Thyroid Cancer to the Brain: A Case Report and Review of the Literature

Medullary thyroid cancer rarely metastasizes to the brain. Presentation and optimal treatment approaches vary widely. We present a 53-year-old male, diagnosed with medullary thyroid cancer 21 years prior, who was presented with at least seven metastases in his brain. He underwent two craniotomies for two large, hemorrhagic metastases followed by whole brain radiation therapy. Tumor genotyping revealed a somatic C634R mutation in the RET proto-oncogene. Subsequently, he was started on multikinase inhibitor therapy. He ultimately passed away 10 months after his surgery. Complete resection may be a reasonable approach for patients with one or more cerebral or cerebellar metastases when feasible. Further analysis is necessary to understand the specific mutations that predispose medullary thyroid cancer to central nervous system metastasis.