Fig 9. Infiltration of the mandible with retropharyngeal spread of tumor. Axial T1-weighted scan demonstrates a large mass emanating from the right palatine tonsil extending along the floor of the mouth posteriorly to infiltrate the right side of the mandible. Note that the signal intensity of the right side of the bone marrow is dark, replacing the bone marrow fat. There is effacement of the retropharyngeal fat on the right side, with tumor abutting the longus colli/capitis muscle complex.