Primary lesions of the root of the tongue.

In the assessment of the head and neck, differential diagnoses can be formulated by subdividing the anatomy into spaces along identifiable and logical boundaries. In the oral cavity, the root of the tongue is notably unlike adjacent regions due to structural and tissue-specific differences. The majority of lesions found in the root of the tongue are congenital and benign, representing ectopic tissues of thyroidal, epidermal, dermal, foregut, venous, and lymphatic origin. A greater number of acquired neoplasms and infections are seen in the adjacent sublingual, submandibular, and oropharyngeal regions of the base of the tongue, presumably due to their greater exposure to mucosal surfaces and lymphatic tissues. Many lesions of the root of the tongue have clinical and imaging characteristics that can help narrow the differential diagnosis, and surgical management may be required. Familiarity with these lesions and how they differ from other lesions of the oral cavity and oropharynx can significantly aid in their diagnosis and treatment.