Pleomorphic adenoma is the most common parotid gland tumor. It accounts for 70-80% of all benign parotid tumors.
Over 84% of pleomorphic adenomas occur in the parotid gland, 8% occur in the submandibular gland, and 6.4% occur in the minor salivary glands.
Pleomorphic adenomas are usually seen in middle aged women and present as a painless slowly growing mass. Typically, these masses are solitary and well demarcated. They may appear heterogeneous secondary to hemorrhage, calcification, and necrosis.
Sarcomatous transformation is seen in only 2-5% of cases and is usually associated with tumors that have been present for 10-15 years.
Pleomorphic adenoma of the minor salivary glands of the palate.
This picture shows the pharyngeal component of a right parotid pleomorphic adenoma that has grown medially and presented as a mass in the parotid region and a corresponding one in the pharynx (dumbell-shape)
Pleomorphic adenoma of the submandibular gland.
Click picture for more details of pleomorphic adenoma of submandibular gland