Pleomorphic adenoma has?
**Core Concept**
Pleomorphic adenoma, also known as benign mixed tumor, is a common type of salivary gland tumor that exhibits a wide range of histological characteristics. This neoplasm is composed of a mixture of epithelial and mesenchymal elements, including myoepithelial cells, resulting in a diverse cellular morphology.
**Why the Correct Answer is Right**
Pleomorphic adenoma is characterized by its unique ability to contain both epithelial and mesenchymal components. The tumor often displays a combination of glandular, ductal, and myoepithelial differentiation, along with the presence of myxoid, cartilaginous, or even osseous tissue. This pleomorphic nature of the tumor is due to the presence of myoepithelial cells, which can differentiate into a variety of cell types.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because pleomorphic adenoma does not typically exhibit malignant behavior, unlike some other salivary gland tumors.
**Option B:** This option is incorrect because while pleomorphic adenoma can occur in the parotid gland, it is not exclusive to this location and can also be found in the submandibular and minor salivary glands.
**Option C:** This option is incorrect because the histological appearance of pleomorphic adenoma is not typically characterized by a predominance of squamous cells.
**Clinical Pearl / High-Yield Fact**
Pleomorphic adenoma is the most common type of salivary gland tumor, accounting for approximately 60-70% of all cases. It is often associated with a slow growth rate and can cause symptoms such as a painless neck mass or facial swelling.
**Correct Answer: A. Benign**