Pituitary metastasis of thyroid cancer.

Pituitary metastases (PM) from thyroid cancer are rare, but their management can represent a difficult challenge for the endocrinologist. Our aim was to review all reported cases of PM from thyroid cancer. PubMed was consulted and 19 papers reporting 20 cases were found. We moreover discuss two of our own cases, which had come to our attention within a few months of one another. Eleven cases were follicular cancer, eight cases were papillary cancer, two cases were medullary cancer, and one case was an insular cancer. In nine cases, PM was the first sign of the disease. Cranial nerve involvement was the most common sign of its presence, and no neuroradiological imaging could lead to a sure diagnosis of PM. Neurosurgical intervention was performed in almost all cases, and post-surgical treatment comprised radioiodine, external beam radiotherapy, and radiosurgery. Prognosis was poor for larger metastases, cranial nerve palsy disappeared in only one case, and in only one case of intrasellar metastasis was the disease cured. PM from thyroid cancer are rare, but are burdened by a poor prognosis. An early diagnosis appears important, and a comprehensive strategy for treatment (neurosurgery, radioiodine, external radiotherapy, and radiosurgery) appears advisable.