Mixed Tumors of the Parotid Gland
The term "mixed tumor" refers to the commonest group of neoplasms of the salivary glands. In the parotid gland, they make up approximately 80% of the benign tumors. They are slowly growing, firm, encapsulated, and freely movable lesions, varying from 1 to 15 cm. in diameter. Grossly, the primary tumor occurs as a single nodule whose cut surface may show varying degrees of cartilaginous consistency. Recurrent lesions are usually multicentric. Long-standing mixed tumors may undergo malignant transformation, as shown elsewhere in this exhibit.
Less Common Benign Tumors and Cysts of the Parotid Gland
1. Warthin's tumor (papillary cystadenoma lymphomatosum) makes up about 7% of the benign group. It occurs predominantly in male patients and is located typically at the posterior margin of the lower pole of the gland. In about 10% of cases, the lesion is bilateral or multicentric. Grossly, these tumors are encapsulated,