Figure 8a. Differentiated squamous cell carcinoma of the nasopharynx. (a) Axial CT scan obtained during quiet respiration shows a tumor of the right and posterior walls of the nasopharynx (arrow). The left margin of the lesion is not clearly seen. (b) Axial CT scan obtained during the Valsalva maneuver shows that the left and posterior walls of the nasopharynx are separated. The tumor is located on the posterior wall (black arrows) and right wall (white arrows). The left wall is preserved (arrowheads).