Definition
Pleomorphic adenoma is a benign salivary gland tumor that exhibits wide cytomorphologic and architectural diversity. The tumor has the following 3 components:
An epithelial cell component
A myoepithelial cell component
A stromal (mesenchymal) component
Identification of these 3 components, which may vary quantitatively from one tumor to another, is essential to the recognition of pleomorphic adenoma. This tumor is also referred to as a benign mixed tumor.