Temozolomide in Treating Patients With Invasive Pituitary Tumors

brain and central nervous system tumors, pituitary chromophobe adenoma, recurrent pituitary tumor, acth-producing pituitary tumor, growth hormone-producing pituitary tumor, prolactin-producing pituitary tumor, pituitary basophilic adenoma, pituitary eosinophilic adenoma, prolactin secreting adenoma, nonfunctioning pituitary tumor, interventional, phase2