You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which of the following head and neck tumor has the worst prognosis? - and explain in detail?
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