This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Surgery
[{'content': 'Pheochromocytomas if extra adrenal are most commonly located in \nSelect and explain. \nA. Posterior mediastinum, B. Superior mediastinum, C. Anterior mediastinum, D. Middle mediastinum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Posterior mediastinumRef: Bailey and love, 26th ed; pg. 869* Neurogenic tumors derived from the sympathetic nervous system or the peripheral nerves, more common in posterior mediastinum.* Mostly incidental findings in Chest radiograph* May be painful also* Includes neuroblastoma in childhood* Schwannomas and neurofibromas in adults, which are usually benign.* Pheochromocytoma arises from the sympathetic chain and produces the characteristic endocrine syndrome.* Excision of neurogenic tumors by thoracotomy, for smaller tumors a VATS approach done.', 'role': 'assistant'}]