Pituitary gland tumour. Coloured three-dimensional computed tomography (CT) scan of an adenoma (a benign tumour, red) of the pituitary gland. This endocrine gland, normally pea-sized, is located at the base of the brain. Here, it is seen with the jaw bones (yellow) and the carotid arteries of the neck (green). The pituitary gland is the master endocrine gland, secreting many hormones that control the function of the body's other endocrine glands. Treatment of the tumour (which is usually successful) will depend on which part of the gland is affected, what hormones the tumour secretes, and hence what symptoms are seen. CT scanning uses X-rays to obtain body images.