Pheochromocytomas can be classified as benign or malignant, with malignant pheochromocytomas growing faster. Pheochromocytoma Pheochromocytoma is chromophilic tissue originating from the adrenal medulla, sympathetic ganglia, or elsewhere. This tumor releases large amounts of catecholamines either continuously or intermittently, causing persistent or paroxysmal hypertension and multiple organ function and metabolic disorders. They can be classified as benign or malignant, with more than 90% being benign and about 10% being malignant tumors. Most pheochromocytomas are benign and slow-growing. Surgical removal of pheochromocytomas is generally the most effective method of eradication, with a 5-year survival rate of more than 96%. On the other hand, malignant pheochromocytoma grows faster and is poorly demarcated from the surrounding tissues, which is prone to hemorrhage, necrosis and cystic changes, as well as invasion and metastasis to neighboring organs. Surgery is the main treatment method, which is not sensitive to radiotherapy and chemotherapy, and the 5-year survival rate is only 43%.