This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Pathology
[{'content': 'Which of the following head and neck tumor has the worst prognosis? - \nSelect and explain. \nA. Adenoid cystic carcinoma, B. Acinic cell carcinoma, C. Cystadenolymphoma, D. Mucoepidermoid carcinoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Adenoid Cystic Carcinoma (Cylindroma)This is a highly malignant tumor due to its typical infiltrativenature, especially along the nerve sheaths. Adenoidcystic carcinoma is histologically characterized by cribriformappearance i.e. the epithelial tumor cells of duct-lining andmyoepithelial cells are arranged in duct-like structures ormasses of cells, having typical fenestrations or cyst-likespaces and hence the name 'adenoid cystic'. HARSH MOHAN Textbook of pathology 6th edition pg no 537", 'role': 'assistant'}]