Adrenal gland tumour. Two halves of a sectioned phaeochromocytoma tumour from the adrenal glands. The adrenal glands are responsible for secreting the hormones adrenaline and noradrenaline. Tumours typically lead to uncontrolled oversecretion of these hormones, which causes high blood pressure, raised heart rate and anxiety. Although benign (non-cancerous) in most cases, phaeochromocytoma may be fatal due to the strain that hormone overproduction puts on the heart and circulatory system. Treatment is removal of the tumour or the entire gland.