Mucoepidermoid Carcinoma

The most common malignant tumour of salivary glands in people of all ages.


An unusual pattern of incidence typifies this tumour. The average age of diagnosis is 45, with less diagnoses at the extremes of age. It can arise from any of the salivary gland sites; about half arise in the major glands.
Incidence, age of onset, gender, geography

Aetiology and Pathogenesis

No specific aetiologies have been identified other than the common salivary gland causes.

Natural History

Tumours may be locally invasive but are often limited by bony boundaries. They spread to local lymph nodes depending on the site of origin. Metastatic spread occurs to the usual sites (bone, brain, lung, liver).

Clinical Presentation

The classical presentation is of a painless lump in the parotid region or within the oral mucosa. Local invasion can cause cranial nerve palsies, pain or bleeding.

Tumour Features

Macroscopically the tumours are light coloured with either infiltrative or well defined borders. Cystic areas may be present.
Microscopically the tumour is comprised of three cell types:

  • An epidermoid squamous component
  • A mucous producing adenocarcinoma-like component
  • An intermediate component

The architecture of these components is variable; usually there is formation of cysts mixed with solid regions.