Hyperthyroidism with an FSH-and TSH-secreting pituitary adenoma

A 34-year-old man was found to have elevated thyroxine (T4), triiodothyronine (T3), calculated free T4, thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), and alpha subunits of TSH and FSH. A computed tomography scan of the head showed a 16-mm macroadenoma of the pituitary gland. There was no evidence of loss or excess secretion of other pituitary hormones. The large chromophobe adenoma was removed via a transphenoidal approach. The patient has been taken off all medication. Thyroid function has returned to normal and there has been no loss of pituitary secretory capacity of other pituitary hormones. The occurrence of a combined TSH- and FSH-secreting pituitary adenoma is rare; to the authors' knowledge, only one case has been documented in the literature.