Parotid Benign
Tumors

This type of tumor accounts for the vast majority of all parotid tumors. They occur not only in the parotid gland but have been found in all salivary glands, including the submandibular gland, sublingual, and even in the minor salivary glands lining the mouth, nose & throat. They tend to grow slowly and have a genetic makeup that predisposes them to transform into cancer if left in the body for too long. It also has little legs on its surface and so requires meticulousness and patience by your surgeon to remove without leaving any of it behind; if removed incompletely, then the tumor will grow in time (7-10 years) to show itself again. Pleomorphic adenomas can grow to become very large or massive. Due to the potential to grow large & transform into an aggressive cancer, it is recommended that pleomorphic adenomas be removed.

A benign tumor that is made up of several components: fluid-filled part (cyst), lymphoid tissue, & salivary tissue. Warthin’s tumor grows slowly and tends not to cause any symptoms except a lump that is felt & may be visible. It happens almost exclusively in the parotid gland (98%). On occasion, the cyst component gets infected & becomes painful. Often, there is more than one Warthin’s tumor, either in the same salivary gland or in multiple glands, and even on both sides (5-10%). It occurs more often in older men and in smokers (92% are smokers). The tendency to be multiple is more likely in smokers. It is more common in Asians & Middle Easterners and uncommon in people of African ancestry.

Hormones, radiation, viruses (EBV & HHV8), and autoimmune diseases (e.g., Hashimoto’s thyroiditis, Sjogren’s syndrome) have been associated with Warthin’s tumor. There has been emerging evidence to suggest that autoimmune processes, combined with a toxic insult from smoking and viruses, may be key in driving this tumor’s formation. The chance of transforming into cancer is very small (1-2%).

Oncocytomas are rare tumors made up completely of oncocytic cells. Oncocytic cells are large and contain excess amounts of mitochondria and eosinophilic granules, which gives the tumor an orange or red hue. Interestingly, oncocytic cells can be found in other tumors (Warthin’s tumor, oncocytic carcinoma, and more). The tumor itself is lobulated and has an obvious capsule. Even though they are benign and don’t spread to other organs, they can be eaten through surrounding tissue and should be removed before they can damage tissue.

Basal cell adenomas tend to happen more often in women older than 40, and can develop even later in life. On needle biopsy, this is a hard tumor to diagnose because it looks similar to other benign and cancerous tumors (pleomorphic adenoma, adenoid cystic carcinoma, and basal cell adenocarcinoma). Treatment is surgical removal with a very low chance of reappearing.

Myopetheliomas are smooth, white tumors with a visible capsule. A subset that has spindle or clear cells under the microscope has a higher chance of turning into a cancer, which is otherwise very low. Most are solid, but some can appear with cysts within them. Treatment is simple surgical removal.