UNUSUAL ASSOCIATION BETWEEN A THYROTROPIN-SECRETING PITUITARY-ADENOMAAND A PAPILLARY THYROID-CARCINOMA

We report here an unusual case of association between thyrotropin (TSH )-secreting pituitary adenoma and papillary thyroid carcinoma in a you ng female patient. Serum TSH levels did not significantly change after both stimulatory (thyrotropin-releasing hormone [TRH], domperidone) a nd inhibitory (bromocriptine levotriiodothyronine, [LT3], levothyroxin e [LT4], LT4 plus LT3) tests, while a 67% decrease of serum TSH levels was obtained after acute administration of a somatostatin analog (SMS 201-995, 100 mu g sc). Serum alpha-subunit levels and the alpha-subun it/TSH molar ratio were clearly elevated. Magnetic resonance imaging ( MRI) revealed the presence of a pituitary adenoma (1 cm in diameter). Pitfalls arising from the failure to inhibit TSH secretion in a patien t thyroidectomized for papillary cancer are discussed.