CRANIOPHARYNGIOMA - A form of primary brain tumor which develops in the pituitary gland. These tumors often secrete increased quantities of pituitary hormones (e.g. growth hormone) which can result in conditions such as gigantism and acromegaly. They are often benign and rare and comprise less than 5% of childhood brain tumors. Other symptoms include vision changes, headache, and weight gain. Treatment often includes a combination of surgery and radiation therapy.