Oncocytoma of the salivary glands

by Jason Wasserman MD PhD FRCPC
November 9, 2022

What is an oncocytoma of the salivary glands?

Oncocytoma is a non-cancerous type of salivary gland tumour. The most common location for this tumour is the parotid gland although it can be found in any of the major or minor salivary glands located throughout the head and neck.

Is oncocytoma of the salivary glands a type of cancer?

No. Oncocytoma is a benign (non-cancerous) type of salivary gland tumour.

What causes oncocytoma of the salivary glands?

Most BCAs are sporadic which means the tumour develops without any known genetic or environmental risk factors. However, some oncocytomas may develop after radiation therapy.

What are the symptoms of oncocytoma of the salivary glands?

Most oncocytomas present as a small painless lump over one of the salivary glands.

How is the diagnosis of oncocytoma made?

The diagnosis of oncocytoma can be made after a small sample of the tumour is removed in either a core needle biopsy or fine needle aspiration biopsy (FNAB). The diagnosis can also be made after the entire is removed in an excision or resection. The tissue removed is then sent to a pathologist for examination under the microscope.

What does an oncocytoma look like under a microscope?

When examined under a microscope, oncocytomas are made up of large pink oncocytic cells. The cells are called oncocytic because the cytoplasm (body of the cell) is full of thousands of mitochondria, a type of cellular machinery that converts oxygen into energy. The oncocytic cells look pink when examined under a microscope because the mitochondria stick to eosin, a pink-coloured dye found in the hematoxylin and eosin (H&E) stain used by pathologists. The tumour may be described as well-circumscribed which means there is a clear border between the tumour and the surrounding normal salivary gland tissue.