Pituitary metastases of Hürthle cell carcinoma of the thyroid.

An 85-year-old man was referred to endocrinology following the discovery of an incidental pituitary mass on cranial imaging which was thought to be a non-functioning adenoma during an admission with headaches, lethargy, confusion and hyponatraemia. He had a history of Hürthle cell carcinoma of the thyroid treated with total thyroidectomy, ablative radioiodine therapy and thyroxine replacement. Subsequently, he developed metastatic spread to the neck, lungs and skeleton.