Cancers of the head and neck are categorised by the area of the head or neck where they begin.These areas are:

• oral cavity: including the lips, gums, lining of the cheeks and lips, front two-thirds of the tongue, floor of the mouth under the tongue, and roof (hard palate) of the mouth
• pharynx (throat): the tube that leads from behind the nose to the trachea (windpipe) and oesophagus; it comprises
  • the nasopharynx (the upper part of the pharynx, behind the nose)
  • the oropharynx (including the soft palate at the back of the mouth, the base of the tongue and the tonsils)
  • the hypopharynx (the lower part of the pharynx)
• larynx (voicebox): including the vocal cords and the epiglottis (a piece of tissue that prevents food entering the trachea)
• nasal cavity: the space inside the nose
• paranasal sinuses: spaces in the bones surrounding the nose
• salivary glands: however, more than half of all salivary gland tumours are benign and do not spread to other tissues.

One type of head and neck cancer, called metastatic squamous neck cancer with unknown (or occult) primary, occurs when cancerous squamous cells are found in the lymph nodes in the neck without any signs of cancer in other parts of the head and neck – that is, it is not known where the cancer started in the body.

Although most head and neck cancers begin in the squamous cells, other types of cells can become cancerous, leading to a number of different types of cancer.

Cancers of other parts of the head and neck region, including the brain, eye, oesophagus and thyroid gland, are usually not categorised as head and neck cancers.