by Kristina-Ana Klaric MD and Jason Wasserman MD PhD FRCPC
March 25, 2023

What is a Warthin tumour?

A Warthin tumour is a non-cancerous type of salivary gland tumour. Most Warthin tumours are found in the parotid gland.

What causes a Warthin tumour?

Warthin tumours are strongly associated with a history of cigarette smoking. For patients without a history of smoking, the cause remains unclear.

What are the symptoms of a Warthin tumour?

Most Warthin tumours present as a slow-growing and painless lump on the side of the face or neck.

Can a Warthin tumour turn into cancer over time?

No. A Warthin tumour will not turn into cancer over time. However, it is not unusual for a patient to have more than one Warthin tumour.

How is this diagnosis made?

The diagnosis is usually made after a small sample of tissue is removed in a procedure called a biopsy or a fine needle aspiration. The diagnosis can also be made after the entire tumour is removed in a procedure called a resection. The tissue is then sent to a pathologist who examines it under a microscope.

What does a Warthin tumour look like under the microscope?

Under the microscope, Warthin tumours have a distinct look. At least some of the tumour will be made up of large pink epithelial cells. Pathologists describe these cells as oncocytic. The cells connect to form two rows, which pathologists describe as bilayered. The tissue below these cells is filled with small round immune cells called lymphocytes. Because of the large number of lymphocytes, a Warthin tumour can sometimes be confused for a type of immune organ called a lymph node. Some Warthin tumours will have large spaces on the inside of the tumour. Pathologists describe these spaces as cysts. The cysts may be filled with fluid or tumour cells.