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Cancer of the head and neck. Nasopharyngeal cancer.

ABSTRACT The nasopharynx is a small boxlike structure at the top of the pharyngeal cylinder. Neoplasms spread in two directions, each leading to distinct neurological signs. Direct extension through the foramen lacerum into the cavernous sinus and middle fossa of the skull leads to the involvement of cranial nerves III, IV, V, VI, and more rarely cranial nerve II. By contrast, spread to the lateral pharyngeal nodes in and about the carotid jugular sheath in the retroparotidian space results in infiltration of cranial nerves IX, X, XI, and XII. Usually cranial nerves VII and VIII are spared. Knowledge of the cranial nerve anatomy is critical to appreciate the extent of disease, and evaluate the patterns of spread.Current Classifications.—Tumor, Node, Metastasis (TNM) System.— Both the Union International Contre le Cancrum (International Union Against Cancer [UICC])1 and the American Joint Committee for Cancer Staging and End Results Reporting