This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'The salivary gland neoplasm which characteristically spreads perineurally along the caranial nerves is \nSelect and explain. \nA. Pleomorphic adenoma, B. Acinic cell carcinoma, C. Mucoepidermoid carcinoma, D. Adenoid cystic carcinoma', 'role': 'user'}, {'content': 'Answer: D \nExplanation: .ADENOID CYSTIC CARCINOMA (10% of salivary tumours) * It is common in submandibular and minor salivary glands. * It consists of myoepithelial cells and duct epithelial cells with cribriform or lace like appearance. * It involves facial nerve very early, spreads through the perineural sheath and infiltrates into the perineural tissues over a long distance, more proximally. * It also invades periosteum and bone medulla early and spreads extensively. * Prognosis is poor. * Radical parotidectomy and radical radiotherapy is the treatment of choice. ref:SRB&;s manual of surgery,ed 3,pg no 369', 'role': 'assistant'}]