Lesions of the tonsillar fossa may be either exophytic or ulcerative and have a pattern of extension similar to those of the anterior tonsillar pillar. These tumors present in advanced-stage disease more often than cancers of the tonsillar pillar. Approximately 75% of patients will present with stage III or stage IV disease.[3,26] The lymphatic drainage is primarily to level V nodes. Tumors of the posterior tonsillar pillar can extend inferiorly to involve the pharyngoepiglottic fold and the posterior aspect of the thyroid cartilage. These lesions more frequently involve level V nodes.
Soft palate tumors are primarily found on the anterior surface. Lesions in this area may remain superficial and in early stages. The lymphatic drainage is primarily to level II nodes.
Tumors of the pharyngeal wall are typically diagnosed in an advanced stage because of the silent location in which they develop.[3,26]
Symptoms of pharyngeal wall tumors may include:
- Weight loss.
- A neck mass.
These lesions can spread superiorly to involve the nasopharynx, posteriorly to infiltrate the prevertebral fascia, and inferiorly to involve the pyriform sinuses and hypopharyngeal walls. Primary lymphatic drainage is to the retropharyngeal nodes and level II and III nodes. Because most pharyngeal tumors extend past the midline, bilateral cervical metastases are common.
Precancerous lesions of the oropharynx include leukoplakia, erythroplakia, and mixed erythroleukoplakia. These are clinical terms that have no specific histopathologic connotations. Leukoplakia, the most common of the three conditions, is defined by the World Health Organization as "a white patch or plaque that cannot be characterized clinically or pathologically as any other disease." The diagnosis of leukoplakia is one of exclusion; conditions such as candidiasis, lichen planus, leukoedema, and others must be ruled out before a diagnosis of leukoplakia can be made.
The prevalence of leukoplakia in the United States is decreasing; this decline has been related to reduced tobacco consumption. Although erythroplakia is not as common as leukoplakia, it is much more likely to be associated with dysplasia or carcinoma.[4,39]