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 salivary gland tumors has highest rate of malignant transformation: and explain in detail?
Tumours of salivary gland tissue constitute about 5% of head and neck tumors and affect major salivary glands five times more than the minor salivary glands. The incidence of malignancy among salivary gland tumours varies inversely with the size of the gland. About 15% of parotid tumors, 50% of submandibular gland tumours, and 90% of minor salivary gland tumours are malignant. Approximately 70% of all minor salivary gland cancers of oral cavity occur on the hard palate.