There are 3 main types of head and neck cancers. These are named after the cell type in which the cancer first develops:

• Mucosal squamous cell carcinomas begin in the squamous cells, or moist lining, of the mouth, nose and throat. Most head and neck cancers are squamous cell carcinomas
• Adenocarcinomas start in the glandular cells of the head and neck area
• Cutaneous carcinomas start in the skin of the head and neck area.

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

• mouth (oral cavity) – includes the lips, gums, lining of the cheeks and lips, front two-thirds of the tongue, floor of the mouth under the tongue, roof (hard palate) of the mouth, and the small area behind the wisdom teeth
• throat (pharynx) – the tube that leads from behind the nose to the trachea (windpipe) and oesophagus (food pipe). It comprises the nasopharynx (the upper part of the pharynx, behind the nose), oropharynx (the middle part of the pharynx, the soft palate at the back of the mouth, the base of the tongue and the tonsils), and the hypopharynx (the lower part of the pharynx)
• voice box (larynx) – includes the vocal cords and the epiglottis (a piece of tissue that prevents food from entering the trachea)
• nose (nasal cavity) – the hollow space behind the nose; also includes the paranasal sinuses (small, air-filled spaces in the nose)
• salivary glands – the major salivary glands are found in front of the ears, under the lower jaw, and under the tongue. However, most 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. This means that the doctors are not sure where the cancer started in the body (see also Cancer of unknown primary).