Conditions and Cancer Types
About 90% head and neck cancers begin in the cells that line the mucosal surfaces in the head and neck area, e.g., mouth, nose, and throat. Mucosal surfaces are moist tissues lining hollow organs and cavities of the body open to the environment. Normal mucosal cells look like scales (squamous) under the microscope, so head and neck cancers are often referred to as squamous cell carcinomas.
Head and neck cancers can also develop from other types of cells:
- Lymphomas develop from the cells of the lymphatic system.
- Adenocarcinomas develop from cells that form the lining of glands in the body.
- Sarcomas develop from the cells which make up muscles, cartilage or blood vessels.
- Melanomas start from cells called melanocytes, which give colour to the eyes and skin.
Cancers of the head and neck are further identified by the area in which they begin:
- Oral cavity - The oral cavity includes the lips, the front two-thirds of the tongue, the gingiva (gums), the buccal mucosa (lining inside the cheeks and lips), the floor (bottom) of the mouth under the tongue, the hard palate (bony top of the mouth), and the small area behind the wisdom teeth.
- Paranasal sinuses and nasal cavity - The paranasal sinuses are small hollow spaces in the bones of the head surrounding the nose. The nasal cavity is the hollow space inside the nose.
- Pharynx - The pharynx is a hollow tube about 5 inches long that starts behind the nose and leads to the esophagus (the tube that goes to the stomach) and the trachea (the tube that goes to the lungs). The pharynx has three parts:
- Nasopharynx - The nasopharynx, the upper part of the pharynx, is behind the nose.
- Oropharynx - The oropharynx is the middle part of the pharynx. The oropharynx includes the soft palate (the back of the mouth), the base of the tongue, and the tonsils.
- Hypopharynx - The hypopharynx is the lower part of the pharynx.
- Salivary Glands - The salivary glands produce saliva, the fluid that keeps mucosal surfaces in the mouth and throat moist. There are many salivary glands; the major ones are in the floor of the mouth, and near the jawbone.
- Lymph nodes in the upper part of the neck. Sometimes, squamous cancer cells are found in the lymph nodes of the upper neck when there is no evidence of cancer in other parts of the head and neck. When this happens, the cancer is called metastatic squamous neck cancer with unknown (occult) primary.
- Larynx - The larynx, also called the voice box, is a short passageway formed by cartilage just below the pharynx in the neck. The larynx contains the vocal cords. It also has a small piece of tissue, called the epiglottis, which moves to cover the larynx to prevent food from entering the air passages.
- Other types of cancer can also be located in this area of the body, but the diagnosis and treatment are much different. Specific information about brain tumors, esophageal cancer, eye cancer, parathyroid cancer, sarcoma, and thyroid cancer is also available in this section.