Cancer of the oropharynx represents 10% to 15% of all cancers of the head and neck. Most of these cancers (50%) occur in the tonsil region, including the tonsil, tonsil fossa, and tonsil pillars.

Unfortunately, most of these cancers are identified in advanced stages. The indolent progression, as well as large number of lymphatics, and a common confusion with infection have been suggested as to why these cancers are diagnosed in advanced stages.

The use of radiotherapy alone or chemoradiation has been the primary treatment option in many centers around the world. Recently the association of cancer of the oropharynx with human papillomavirus has been described and explains the increased incidence of this tumor in young patients.

The tonsil fossa, which contains the tonsil, is limited by the anterior tonsillar pillar (palatoglossus muscle) and the posterior tonsil pillar (palatopharyngeal muscle).

Lateral to the tonsil fossa are the pharyngeal muscles, the mandible, and the parapharyngeal space. The carotid artery is just lateral and posterior to the tonsil fossa. In this region, special care should be taken to avoid injury to these structures (Fig. 12.1).

A careful clinical examination must be done with inspection and palpation including the parapharyngeal space for correct staging of the primary cancer of the oropharynx and the neck. Infiltration of the oral tongue, the base of the tongue, and the vallecula is identified by palpation. Many times this infiltration is submucosal, preventing direct visualization. This examination is very important before the surgery because invasion of these structures is a contraindication to surgery.