Hyperthyroidism due to thyrotropin-secreting pituitary tumors

Two patients with thyrotropin-secreting pituitary tumors were reported. And their clinical characteristics were analyzed retrospectively. Patients were presented with thyrotoxicosis and one had visual field defect. Hyperthyroidism was determined in these patients by means of elevated total or free thyroid hormone levels while serum TSH levels were not lower than detect limits. They were previously considered as suffering from primary hyperthyroidism and were treated with antithyroid drug for 4 to 7 years, one of them subsequently underwent subtotal thyroidectomy. MRI showed pituitary macroadenomas in 1 patients who underwent transsphenoidal adenomectomy and followed by radiotherapy, while microadenomas in the other patient who was given radiotherapy. Thyrotropin-secreting pituitary adenoma should be considered in patients with el-evated thyroid hormone and non-suppressed serum TSH level. Combined treatment with transsphenoidal adenomectomy and radiotherapy are the choice for thyrotropin-secreting pituitary tumors. Key words: Thyrotropin-secreting pituitary tumors;  Thyrotoxicosis;  Diagnosis