Pleomorphic adenoma is best described as which type of tumor?

• A. Benign mixed tumor
• B. Malignant epithelial tumor
• C. Malignant mesenchymal tumor
• D. Benign lymphoid tumor

Answer: (A)

Pleomorphic adenoma is a benign mixed tumor. It contains both epithelial elements (ducts and acini formed by epithelial/myoepithelial cells) and a mesenchymal-like stroma that can be myxoid, chondroid, or even osseous. This combination gives the tumor its “mixed” designation, and the term pleomorphic reflects the variable histologic appearance rather than any malignant behavior. It is a non-malignant salivary gland tumor, most commonly arising in the parotid.