Skull metastasis with brain invasion from thyroid papillary microcarcinoma

Thyroid papillary microcarcinoma has a notably benign clinical course among carcinomas. The occurrence of distant metastases is exceptional, but significantly increases the risk of mortality. We report the case of a 75-year-old woman with a 1.0 cm primary thyroid papillary microcarcinoma with skull metastases and brain invasion. The clinical presentation was a large mass over the occipital area which progressively grew over the course of 1 year. No thyroid nodule or lymph nodes were palpable. The metastatic mass and primary tumor were surgically removed. The serum thyroglobulin level was 163 ng/mL 1 month after surgery. There was no further management because the patient refused follow-up. She returned to the hospital 15 months later due to a seizure. The tumor had further extended into the brain tissue. Her condition progressively deteriorated and she died 2 months later due to uncontrollable seizures.