The hypopharynx is below the oropharynx. It is the place the food first passes through when we swallow. There are three areas in the hypopharynx:
• postcricoid area (junction of pharynx and esophagus);
• pyriform sinus; and
• posterior (back) pharyngeal wall.
This area is best examined with mirrors, fingers or scopes that can be passed into the mouth. Almost all of the cancers in this area are squamous (or epidermoid) cancers arising in the mucous membranes. A few cancers are of minor salivary gland origin.
These cancers first spread by direct invasion, growing down from the surface membranes into the next layer (the submucosa), then into the muscles and finally into the tissues that surround the pharynx. Further spread is to the lymph nodes in the neck (even at this stage the cancer may still be curable), then to the lungs and elsewhere in the body (where the chance of cure is very remote).
Sometimes these cancers begin with a white plaque or coating on the membrane (leukoplakia), a premalignant condition similar to that found in the mouth, but many cancers begin without any preliminary change. Not all white patches are leukoplakia , and biopsy is necessary to rule out other causes, such as fungal infections or a disease called lichen planus.
Other cancers may occur elsewhere in the head and neck at the same time or later, so the larynx, pharynx, nasopharynx and the entire oral cavity should be searched. The esophagus should also be evaluated. CT and
