Pediatrics Endocrinology e51b5e03 Pheochromocytoma is the disease of: A Pituitary gland B Adrenal medulla C Pancreas D Adrenal cortex High-Yield Explanation b. Adrenal medulla(Ref: Nelson's 20/e p 2227-2729, Ghai 8/e p 525)Pheochromocytoma is a neoplasms of chromaffin cells in medulla that release catecholamines.