GH1 and hyperprolactinemia: Among all the patients with prolactin-positive tumors (n=184), those with hyperprolactinemia (n=90) had larger tumors (p<0.001) and higher levels of GH (p=0.026) and GH nadir (p=0.024), and their tumors were more likely to invade into cavernous sinus (p=0.003) and sphenoidal sinus (p=0.001), compared to the patients without hyperprolactinemia (n=94).