Mixed tumors of the salivary glands are characterized by which of the following?

There are approximately 400 to 700 minor salivary glands in the oral cavity. Pleomorphic adenomas (mixed tumors) can occur in any of them. These round tumors have a rubbery consistency and are slow-growing; all are potentially malignant. Unless adequately excised, they tend to recur locally in a high percentage of cases. The sites most commonly affected by pleomorphic adenomas of the salivary glands are the lips, tongue, and palate.