An Aggressive Plurihormonal Pituitary Adenoma With Thyrotropin, Growth Hormone, and Prolactin Excess

A 31-year-old gentleman presented with clinical hyperthyroidism, goiter, bitemporal hemianopia, and discordant thyroid function test. The high α-subunit and absence of throtropin (thyroid-stimulating hormone; TSH) response to thyrotropin-releasing hormone stimulation indicated a TSH-secreting pituitary tumor. Elevation in prolactin and growth hormone as well as secondary hypogonadism were also observed. A sellar-suprasellar mass displacing the optic chiasm was revealed upon magnetic resonance imaging. The patient was rendered euthyroid with carbimazole and Lugol's iodine before undergoing endoscopic transsphenoidal surgery. Due to the incomplete tumor excision during surgery, patient experienced recurrence of symptoms and rising thyroxine (T4) with nonsuppressed TSH. The histopathology examination demonstrated a plurihormonal tumor with positive immunohistochemical stain for TSH, growth hormone, and prolactin, with invasive and proliferative features. Subsequently he was initiated with a long-acting somatostatin analogue and underwent stereotactic radiosurgery. To date, his symptoms have improved, with a reduction of insulin-like growth factor 1 and normalization of other pituitary hormones as well as a slightly reduced size of the pituitary tumor.