Case 3. Schwannoma of the maxillary sinus in a 24-year-old woman. A and B, Precontrast axial and coronal CT scan with a bone algorithm shows a lobulated expansile mass arising from the left infraorbital canal, which replaces the left maxillary sinus. Note cortical thinning and remodeling of the orbital floor and the medial and posterior maxillary sinus walls by the mass. C, Fat-suppressed axial T2-weighted MR image shows multiple fluid-fluid levels within the lesion, which are suggestive of intratumoral hemorrhage. D, Contrast-enhanced fat-suppressed coronal T1-weighted MR image shows cystic change at the lower part of the mass and marked enhancement in the upper solid part of the mass.