Papillary thyroid microcarcinoma presenting as a metastasis to the brain

The brain is a particularly rare site of metastasis from papillary microcarcinoma, with only few cases described in the literature. We present a case of 59-year-old man who presented with seizures and dysphasia due to left frontal lobe cystic mass, which was excised and turned out on histopathology to be of thyroid origin. Total thyroidectomy was performed and histology showed multifocal papillary microcarcinoma with the largest focus of 3mm with no other adverse features. The patient had ablative radioactive iodine postoperatively, with subsequent exit scan showing no uptake in the brain. Follow-up brain magnetic resonance imaging showed continuous regression of the surgical cavity. Although rare, such cases should be aggressively treated and followed up over the long term, because of reported associated high mortality.