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Introduction

In this chapter we review benign and malignant tumors of the oral cavity, pharynx, and esophagus. To aid understanding of the descriptions of those conditions, we first cover the anatomy of those sites, as well as nontumor conditions that can give rise to or are considered in the differential diagnosis of cancer.

Traditionally, the oral cavity and pharynx have been grouped together for epidemiologic study and ease of categorization. However, the benign and malignant lesions of the oral cavity and pharynx differ greatly in anatomic, etiologic, biologic, and pathologic features. Furthermore, the pharynx is subdivided into three distinct regions: the oropharynx, hypopharynx, and nasopharynx (Figure 45-1).

Figure 45-1

The pharynx is divided into three distinct anatomic subsites. The soft palate, hyoid bone, and cricoid cartilage serve to demarcate each region.

Anatomy

Oral Cavity

The oral cavity extends from the cutaneous-vermilion junction of the lips to the anterior tonsillar pillars. The posterior border of the oral cavity also includes the circumvallate papillae inferiorly and the junction of the hard and soft palate superiorly. The oral cavity is divided into seven anatomic subsites:

  • Lips

  • Oral tongue, anterior two-thirds

  • Floor of mouth

  • Buccal mucosa

  • Gingiva (alveolar ridges), upper and lower

  • Retromolar trigone (RMT)

  • Hard palate

Salivary Glands and Ducts

  • Parotid (Stenson): orifice lateral to second molars. Produce two-thirds of mouth’s saliva when stimulated.

  • Submaxillary (Wharton): orifice in midline floor of mouth adjacent to lingual frenulum. Produce two-thirds of mouth’s saliva when unstimulated.

  • Sublingual (Rivinus): multiple orifices draining into floor of mouth or submaxillary duct.

  • Produce an average of 1500 mL saliva per day; this amount is reduced by radiotherapy and medications (primarily anticholinergics).

  • Saliva is 99.5% water, with an electrolyte composition of sodium 10 mEq/L, potassium 26 mEq/L, chlorine10 mEq/L, and bicarbonate 30 mEq/L and organic components including glycoprotein and amylase (which is distinct from pancreatic amylase). Saliva pH varies from 6.2 to 7.4.

Teeth

  • Deciduous teeth: 20

  • Adult teeth: 32, numbered superiorly right to left (1-16), and inferiorly left to right (17-32)

Tongue

Surface

  • Papillae: very small protrusions covering the anterior two-thirds of the tongue. There are four types: filiform (no taste function), fungiform (diffuse), foliate (lateral tongue), and circumvallate (large, form a V-shape at the junction of the anterior and posterior portions of the tongue).

  • Sulcus terminalis: groove at the anterior margin of the circumvallate papillae.

  • Foramen cecum: pit at the junction of the sulcus terminalis from which the embryologic thyroid begins its descent.

  • Frenulum: anterior fold of mucous membrane that attaches the anterior inferior aspect of the tongue to the floor of mouth and gingiva. Wharton salivary ducts open on either side of ...

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