Ablative thyroid treatment for thyrotoxicosis due to thyrotropin-producing pituitary tumours.

Thyrotropin (TSH)-secreting pituitary adenomas (TSHomas) are rare tumours. It has been suggested that thyroid surgery or radioiodine treatment should not be considered in patients with such tumours as these treatments may facilitate rapid tumour expansion. We studied the effects of thyroid ablative treatment on tumour size and thyroid status in two patients with TSHomas. Patients studied were: (1) a female with a TSHoma who declined to undergo pituitary surgery and underwent a total thyroidectomy instead and (2) a male patient who opted for radioiodine treatment for his recurrent TSHoma. Changes in tumour size on serial magnetic resonance imaging scans, and restoration of euthyroidism were studied. No marked changes in tumour size or features of aggressiveness occurred in these patients over periods of 8 and 12 years. Euthyroidism was restored and maintained in both patients. Ablative thyroid treatment can be a safe and successful option to treat TSHomas.