Brain metastases from papillary adenocarcinoma of the thyroid

Papillary thyroid adenocarcinoma (PTA) is the most common type of thyroid malignancy. Distant metastatic spread is relatively rare, most commonly affecting the lungs and bone. Brain metastases are very uncommon. We present a series of four patients with this development and review their diagnosis and treatment.

A retrospective chart review analysis of patients diagnosed with PTA between 1983 and 2003 at St. Joseph's Healthcare Centre in Hamilton, Ontario, was conducted.

Four patients with brain metastasis from their PTA were identified. Three were female and one was male. Their ages at the initial presentation ranged from 20 to 67 years (mean 48 years). The time between the initial treatment and presentation of distant metastasis ranged from 15 to 167 months (mean 89 months). Thyroglobulin data were followed on all four patients. Thyroglobulin results rose with the development of brain and other distant metastasis for two patients but never increased in the other two patients despite distant metastases at multiple sites. Treatment of brain metastasis was with a combination of surgery, external beam radiation, and radioactive iodine. All patients eventually died of their disease, and the overall survival after the diagnosis of brain metastases was 15.3 months in the four patients.

This study shows that brain metastasis may or may not be the first site of distant metastasis in patients with PTA. The distant metastasis cannot always be predicted from thyroglobulin data. Once brain metastases are diagnosed, palliation with preservation of quality of life becomes the goal of therapy.