[Basedow's disease and thyroid stimulating hormone producing pituitary adenoma in a patient]

TSH-producing adenomas of the pituitary gland are very rare. Synchronous combinations of TSH-producing adenomas with other causes of hyperthyroidism are certainly extremely rare. We present the second known case, reported in the literature, consisting of observations for 12 years in a woman aged 43 years, who presented with active Graves' disease and an apparently inactive pituitary macro-adenoma. However, after normalisation of serum T3 and serum T4 levels by antithyroid medication for one year, the serum TSH rose inappropriately and continued to rise for the following 11 years. Insidious growth of the adenoma also occurred. After one year of medical treatment, a huge goitre was resected (210 g) leaving the patient euthyroid, clinically and biochemically, for four years. Hereafter, hyperthyroidism developed again this time without Graves' disease. We conclude that the patient experienced hyperthyroidism on two occasions, the first caused by Graves' disease and then caused by a TSH-producing pituitary adenoma.