Caption

Light micrograph of a section through a human adrenal gland showing pheochromocytoma. This is a rare, usually non-cancerous (benign) tumour that arises from certain cells known as chromaffin cells, which produce hormones necessary for the body to function properly. Most pheochromocytomas originate in one of the two adrenal glands located above the kidneys in the back of the upper abdomen. The tumour releases hormones that may cause high blood pressure, sweating and symptoms of a panic attack.