Thyroid Carcinomas with Brain or Skull Metastases. Review

Abstract

The head (brain or skull) is a rare metastatic site for thyroid carcinomas. We analyzed retrospectively 20 patients with head tumors combined with a current or previous thyroid carcinoma between February 1995 and December 2004. There were 4 men and 16 women. Patients with a second malignancy were excluded. The mean age at the time of diagnosis of primary thyroid carcinoma was 60.2 +/- 16.0 years (mean +/- standard diagnosis). The histologic types of thyroid carcinoma included 7 papillary carcinomas (PTC), 10 follicular carcinomas (FTC), one Hurthle cell carcinoma (HTC ), one anaplastic carcinoma, and one medullary carcinoma. Seventeen patients' (85%) metastases were found after diagnosis of primary thyroid carcinoma. The mean interval was 68.0 +/- 74.5 months. Nineteen patients (95%) had other distant metastatic lesions before head metastases were discovered. There was no survival difference between brain and skull metastases (P = 0.07). In the brain metastatic group, there was no survival difference between papillary and follicular thyroid carcinoma (P = 0.56). Patients who received treatment of brain metastases did not have significantly longer survival than those who refused treatment (P = 0.38). However, a tendency of longer survival could be found in the following 3 conditions: skull metastases rather than brain metastases, differentiated thyroid carcinoma (PTC, FTC, and HTC) rather than anaplastic and medullary carcinomas, and treated brain metastases rather than untreated. Head metastases from thyroid carcinomas are more common in women and older patients. Although selection bias inherent to retrospective survey and small case numbers limit conclusions, we suggest that radiotherapy or surgical resection of head metastases may prolong survival in differentiated carcinoma.