Single brain metastasis from thyroid cancer: Report of twelve cases and review of the literature

Brain metastases from thyroid carcinoma is unusual, with a frequency of 1%. We report twelve patients, with single brain metastases and with a karnofsk y performance scale score >60 at admission. No metastasis was seen during t he uptake of iodine-131, even in the cases from differentiated thyroid ;car cinoma, suggesting absence of differentiation between primary and metastasi c disease. The histopathology of thyroid carcinomas was anaplastic in five cases: differentiated in six, and medullary in one. Only in four patients, brain was the unique site of metastatic spread; in others, bones and lungs were also involved. All metastases were surgically removed, and all patient s were treated with radiotherapy (45 Gy) in the postoperative course. The s urvival average was 19.8 months, and the quality of life was satisfactory i n all patients. One patient remained alive till 5 years. Anaplastic histopa thology and size of the primitive, and also bone involvement of thyroid dis ease were significant risk factors in our cases (p < 0.05). According to th e literature, surgery is the best therapeutical choice. Alternative strateg ies in the management of brain metastasis, such as iodine-131 therapy, are discussed, paying particular attention to the relevant side effects.