fig24

Figure 24. SNUC. (A) Coronal CT image of the paranasal sinus shows diffuse soft-tissue opacification of the right nasal cavity and ethmoid complex, with erosion of the ethmoid septa. The maxillary sinus is also opacified with lower attenuation; (B) Coronal T2-weighted MRI of the same patient shows intermediate tumor signal (red arrow). Maxillary sinus opacification appears hyperintense, consistent with retained secretions (yellow arrow); (C) Post-contrast T1-weighted MRI shows heterogeneous tumor enhancement (red arrow). The maxillary sinus demonstrates enhancing thickened mucosa, consistent with inflammatory disease (yellow arrow). SNUC: Sinonasal undifferentiated carcinoma; CT: computed tomography; MRI: magnetic resonance imaging.