Squamous Cell Carcinoma - Base of Tongue

•  Also known as lingual tonsil squamous cell carcinoma (SCCa)
•  Epithelial tumor of epidermoid origin arising in the lingual tonsilar area of the oropharyngeal mucosal space
•  Lingual tonsils are part of the Waldeyer lymphatic ring located just posteriorly to the circumvallate papilla of the tongue
•  Symptoms from this tumor occur late, so tumor is often large (>4 cm) at presentation
•  Lesion can either be exophytic, invasive, or both
•  Spread patterns:
  •  Anterior: sublingual space, oral tongue root, or floor of mouth
  •  Posteriolateral: anterior tonsillar pillar
  •  Inferior: supraglottic larynx and hypopharynx space
•  On CT: Mucosal asymmetry and moderate enhancement with contrast, difficult to assess superficial spread, deep spread easily noted
•  On MR: On T1 lesions are isointense to muscle and spread easily noted; on T2 lesions are iso- to hyperintese; post-contrast T1 shows enhancement
•  Smoking and alcohol are known risk factors
•  Most common nodal involvement is level II nodes
•  Men and those over 40 are most commonly affected
•  Lungs more so than bones more so than liver are the organs where metastasis is most commonly noted