The different types of head and neck cancer are primarily based on the site of origin. The most common types of head and neck cancer are classified into the following groups.

• Oral cavity. This area includes the lips, front and middle of the tongue, gums, lining of the cheeks, floor of the mouth, the hard palate and the area behind the wisdom teeth.
  
  
• Salivary glands. The major salivary glands are located on the floor of the mouth and near the jawbone. These glands produce saliva, the fluid that keeps the mouth and throat moist. Saliva is necessary to swallow and digest food. These cancers are often adenocarcinomas and not squamous cell cancer.
  
  
• Nasal cavity and sinuses. The nasal cavity is the space inside the nose. The sinuses are the small hollow spaces in the bones of the head surrounding the nose.
  
  
• Pharynx. The pharynx is a tube that is runs between the back of the nose and the esophagus, the tube that goes to the stomach. The pharynx is divided into three parts:
  
  
• Nasopharynx. The upper part of the pharynx that is located behind the nose.
  
  
• Oropharynx. The middle part of the pharynx that includes the soft palate (back upper roof of the mouth), the base of the tongue and the tonsils.
  
  
• Hypopharynx. The lower part of the pharynx that is closest to the esophagus.
  
  
• Larynx. The larynx is commonly called the voice box. It is largely composed of cartilage and is located below the pharynx in the neck. The larynx is divided into three regions:
  
  
• Supraglottis. This upper section contains cartilage and the epiglottis, a piece of tissue that moves to protect the airway from food.
  
  
• Glottis. This middle section contains the vocal cords, which are used to produce the voice.
  
  
• Subglottis. This lower section is the cartilage that connects to the windpipe (trachea).
  
  
• Lymph nodes in the upper neck region. In some instances, cancer is found in these lymph nodes with no obvious cancer in other parts of the head and neck. This cancer is called metastatic cancer with unknown primary.