Isolated Thyrotropin Deficiency Secondary to Primary Empty Sella in a Patient with Differentiated Thyroid Carcinoma: An Indication for Recombinant Thyrotropin

The primary empty sella syndrome is a common radiographic finding that is rarely associated with clinical pituitary dysfunction. Studies using dynamic endocrine testing, however, have shown altered pituitary reserve in some patients with the primary empty sella syndrome. We describe a patient with a primary empty sella and an isolated deficiency of thyrotropin reserve. This case is complicated by the presence of an aggressive metastatic papillary epithelial carcinoma of the thyroid. Standard treatment with radioactive iodine was unlikely to be effective in this patient due to the need for adequate thyrotropin (TSH) stimulation of the malignant tissue to optimize uptake of radioactive iodine by the tumor cells. Consequently, this patient was treated with human recombinant TSH before receiving radioactive iodine. The utility of this novel therapeutic agent and a review of hormonal abnormalities associated with the primary empty sella are also discussed.