Local tumor invasiveness. (A) Thinning of right medial wall of maxillary bone (arrow) in CT of paranasal sinuses. (B) Palatal perforation on physical examination. (C) High signal intensity of hard palate is not delineated in T1-weighted MRI (arrow). (D) Skin infiltration by tumor (arrow) in CT of paranasal sinuses. Picture was taken with an Olympus Camedia C4000Z camera (Olympus, Tokyo, Japan). Adobe Photoshop 6.0 was used to process images (Adobe, San Jose, CA).