CRANIOPHARYNGIOMA

brain tumour arising from Rathke's pouch, an embryonic remnant posterior to and above the pituitary gland. Although most common in children, it can occur at any age and is believed to arise from epithelial tissue along a track between the pituitary and the brain. As it grows, the tumour compresses the optic nerve and other nearby structures, causing loss of vision, headaches, vomiting, behavioral changes, and sometimes loss of the sense of smell. Because of the proximity and frequent involvement of the pituitary, endocrine disorders like those caused by pituitary tumours may occur.