subject: Head Neck Cancer Treatment In India At Low Cost. [print this page] Head and neck cancer
overview
Head and neck cancer actually includes many different malignancies. The way a particular head and neck cancer behaves depends on the site in which it arises (the primary site). For example, cancers that begin on the vocal cords behave very differently than do those that arise in the back of tongue, just an inch or less from the vocal cords.
The most common type of cancer in the head and neck is squamous cell carcinoma, which arises in the cells that line the inside of the nose, mouth and throat. Other less common types of head and neck cancers include salivary gland tumors, lymphomas and sarcomas.
Cancers spread in three main ways. - The first is direct extension from the primary site to adjacent areas. - The second is spread through the lymphatic channels to lymph nodes. - The third is spread through the blood vessels to distant sites in the body.
In head and neck cancer, a spread to the lymph nodes in the neck is relatively common.
The lymph nodes most commonly involved are located along major blood vessels underneath the sternocleidomastoid muscle on each side of the neck, particularly the internal jugular vein node at the angle of the jaw. The risk of spread to other parts of the body through the bloodstream is closely related to whether the cancer has spread to the lymph nodes in the neck, how many nodes are involved, and their location in the neck. The risk is higher if cancer is in lymph nodes in the lower part of the neck rather than only in those located in the upper neck.
Most 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. Some head and neck cancers begin in other types of cells. For example, cancers that begin in glandular cells are called adenocarcinomas.
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.
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.
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.
Larynx. The larynx, also called the voicebox, 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.
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.
Cancers of the brain, eye, and thyroid as well as those of the scalp, skin, muscles, and bones of the head and neck are not usually grouped with cancers of the head and neck.
