Treatment of pituitary tumor depends on the type of tumor, its size, and how far it has grown into the brain. The doctor may recommend waiting and seeing if the tumor grows or may prescribe medication to manage your hormones and/or shrink the tumor. Radiation may be an option, with or without surgery. If the tumor is large and cannot be removed through transsphenoidal surgery, a craniotomy may be necessary. This involves removing a piece of the skull to access the tumor.