Follicular Thyroid Carcinoma with Metastases to the Pituitary Causing Pituitary Insufficiency

Background: Pituitary metastases are found in about 1% of all pituitary resections. They often derive from breast, lung, and gastroenteric tract adenocarcinomas, very rarely from thyroid carcinoma. Presenting symptoms of thyroid carcinoma metastatic to the pituitary gland are usually chiasmatic with central neurological impairment due to space-occupying expansion in the parasellar region. Hypopituitarism is more often associated with papillary and medullary rather than follicular thyroid carcinoma (FTC). Here we describe a patient with pituitary metastasis from FTC who had hypopituitarism with thyrotropin (TSH) deficiency. Summary: A 61-year-old woman, who presented with visual deficits and pain to the right orbit, was found on magnetic resonance imaging to have a large mass involving the pituitary gland. She was found to have pituitary insufficiency based on corticotropin-releasing hormone and TSH-releasing hormone testing. Transnasopharyngeal biopsy of the mass revealed metastases from FTC. After total ...