This is a phase II, open-label, 12-month pilot study in 10 patients with silent corticotroph pituitary tumors testing the hypotheses that Pasireotide LAR (long-acting release) treatment of patients with silent corticotroph pituitary tumors and elevated plasma Proopiomelanocortin (POMC) levels will reduce plasma POMC levels and this will be associated with a reduction in pituitary tumor size. Pasireotide LAR 40 mg will be administered monthly. Baseline and monthly visits on therapy will monitor plasma levels of POMC, other pituitary function, safety labs, glucose tolerance, physical examination, and visual fields. Pituitary magnetic resonance imaging (MRI) will be done at baseline, 6 months and 12 months of therapy. The eligible patient population will consist of adult patients with known silent corticotroph pituitary tumors and elevated plasma levels of POMC.