Cerebellopontine angle metastasis from papillary carcinoma of the thyroid:Case report and literature review

BACKGROUND Papillary thyroid carcinoma is the most common type of well-differentiated thyroid malignancy and typically has an excellent prognosis and a low incid ence of distant metastasis. However, once metastasis has developed in a dis tant site, prognosis is markedly diminished. Brain metastases from papillar y thyroid carcinoma are extremely rare. Currently, there are no established therapeutic guidelines for treating brain metastases from thyroid carcinom a. CASE DESCRIPTION We report on the case of a patient who presented with worsening neurologica l symptoms 3 years after resection of a thyroid papillary carcinoma. Magnet ic resonance imaging identified a lesion of the cerebellopontine angle that encased the lower cranial nerves. The patient underwent a left retrosigmoi d craniotomy with a 98% resection of the mass and received postoperative ad juvant radioiodine therapy, external beam radiation, and Gamma Knife radios urgery. The patient tolerated the procedure well and demonstrated significa nt progressive improvement ment in her neurological symptoms postoperativel y. After the multimodal approach to therapy, she remains symptom-free at 3- year follow-up. Radiographic monitoring of the small tumor remnant reveals a decrease in size from the postoperative period. CONCLUSION This article is the first formal case report of cerebellopontine angle meta stasis from papillary thyroid carcinoma. Therapeutic protocols for brain me tastases of papillary thyroid carcinoma are not firmly established. This ca se illustrates the unique event of a cerebellopontine angle metastasis from papillary thyroid carcinoma, which was successfully treated with a combina tion of surgical, chemical, and radiological modalities. This aggressive co urse of therapy has resulted in an excellent outcome in this instance. (C) 2000 by Elsevier Science Inc.