A TSH-secreting pituitary microadenoma diagnosed with inferior petrosal sinus sampling: Case report / 대한내과학회지

ABSTRACT

Thyroid stimulating hormone (TSH)-secreting pituitary adenomas are rare tumors of the pituitary gland and represent 1~2% of all pituitary adenomas. A TSH-secreting pituitary adenoma shows as a normal or elevated thyrotropin level in a hyperthyroid patient. We present a 32-year-old woman who was diagnosed with a TSH-secreting pituitary microadenoma. She had a high free T4, with a normal TSH and alpha-subunit. Bilateral inferior petrosal sinus sampling (IPSS) was done to confirm the alpha-subunit secreting adenoma, and the concentration of the alpha-subunit was high on the tumor side. The pituitary microadenoma was removed, and her TSH and free T4 levels decreased to normal. IPSS may help give an accurate diagnosis in the patient with a normal alpha-subunit.