MON-446 Anaplastic Thyroid Cancer Presenting with Brain Metastasis: 17-Year Progression Free Survival

Abstract Anaplastic Thyroid Cancer is the most aggressive thyroid cancer with a median survival of just five months. Long term survival has been reported in locally aggressive cases but has yet to be reported in metastatic disease. This is a report of a 34-year-old male who presented with symptoms of dizziness, confusion, intermittent headaches, and erratic behavior for two weeks found to have metastatic anaplastic thyroid cancer. CT of the head revealed a 1 cm ring enhancing lesion and he was taken to the operating room for a left parietal craniotomy with mass removal. Initial pathology suggested papillary thyroid origin. His neck exam revealed a palpable 3 cm mass in the right thyroid lobe and he subsequently underwent total thyroidectomy. Final pathology revealed anaplastic carcinoma identical to the brain lesion. Post-operatively, he underwent 15 cycles of whole brain radiation therapy. Two additional brain lesions were identified after thyroidectomy and a third was identified after whole brain radiation. He underwent stereotactic radiosurgery of these three lesions less than two months after thyroidectomy. The patient went on to receive modified mantle field irradiation to the neck, thyroid bed, and the upper mediastinum and chemotherapy with doxorubicin for 6-8 weeks and temozolomide for 2 years. Radioactive iodine treatment was not administered. The patient has currently survived 17 years and his persistent, but stable, brain lesions are being followed with serial imaging. He remains clinically and neurologically asymptomatic. This is the first case presenting with long-term survival in a patient with metastatic anaplastic thyroid carcinoma.