Thyroid-stimulating hormone pituitary adenomas and hyperthyroidism.

Six cases of hyperthyroidism secondary to thyroid-stimulating hormone (TSH)-hypersecreting pituitary adenomas are presented (five females and one male). Hyperthyroidism presenting with diffuse goiter was associated with hyperprolactinemia in three cases. Elevation of triiodothyronine (T3) and thyroxine (T4) plasma levels was associated with TSH levels ranging between 2 and 2,000 microU/mL. Polytomography and computed tomography scanning with coronal views revealed four invasive and two enclosed tumors. Two patients underwent transfrontal operations, four underwent transsphenoidal operations, and one underwent both. Two cases of enclosed adenoma were cured primarily by a transsphenoidal approach without additional pituitary deficit. In four cases of invasive adenomas, operations and radiation therapy resulted in three failures and one cure. In cases presenting with hyperthyroidism and detectable TSH, early neuroradiological studies are indicated, as biological cure can be achieved by the transsphenoidal approach. Early treatment is also advocated because of the tendency for these tumors to become invasive (four out of six tumors).