Craniopharyngioma brain tumour (orange, round) in a childs head, coloured magnetic resonance imaging (MRI) scan. This is a side view, with the front of the head at left. This is a slow-growing tumour, which in the childhood form develops from the remnants of the Rathke pouch, an embryonic structure of the lower brain. The tumour can grow large before being diagnosed, causing headache, growth failure, delayed puberty and hormonal imbalances. Surgical removal of the tumour can effect a cure, especially when combined with subsequent radiotherapy, but the delicate nature of the surrounding tissues makes it hazardous. Risks include blindness, diabetes and social problems due to hypothalamic damage.