Papillary thyroid carcinoma with brain metastases: an unusual 10-year-survival case.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy with indolent clinical course and good prognosis. Brain metastases are extremely rare and the average survival time after diagnosis has been reported to be around 12 months.
SUMMARY: We here report a 69-year-old patient who was admitted to the emergency room in January 2000 with progressive dizziness, headache, and vomiting. Five years before admission the patient underwent partial thyroidectomy for goiter. On admission, a diagnostic evaluation that included brain magnetic resonance imaging showed multiple brain lesions, and a stereotactic biopsy demonstrated a metastatic carcinoma from primary PTC, with the neoplastic cells staining for thyroglobulin. Total thyroidectomy was then performed, which showed colloid goiter and a PTC metastasis on a cervical lymph node. The patient received 200 mCi of radioactive iodine ((131)I) with suppressive therapy with l-thyroxine thereafter. Subsequently, serial whole-body scanning and magnetic resonance imaging showed multiple brain metastases and the patient received further (131)I treatment, with a total dose of 1.2 Ci in a 10-year span. She also underwent partial surgical resection of brain metastases because complete resection was not feasible. Thereafter, the patient was subjected to whole-brain body radiotherapy with a dose of 44 Gy, followed by two brain gamma knife radiosurgeries (15 Gy each). To date, biochemical tests are within the normal range and the patient remains asymptomatic.
CONCLUSIONS: To our knowledge, this is the first report of a 10-year-survival case of brain metastases from PTC, despite this being a bad prognostic factor. A combined approach of surgical excision, (131)I, whole-brain radiotherapy, and gamma knife radiosurgery was successful to treat metastases derived from primary tumor.