fig 2.

Case 2. A, Axial unenhanced CT scan shows a large expansile maxillary sinus mass with extension into the nasal cavity, the nasopharynx, the infratemporal fossa, and the subcutaneous tissues of the left maxillary region.

B, Coronal unenhanced CT scan shows a large expansile mass in the left maxillary sinus that erodes the sinus walls and extends into the nasal cavity, left orbit, and subcutaneous soft tissues of the maxillary region.

C, Poorly differentiated neuroendocrine carcinoma infiltrating maxillary bone. The tumor consists of small pleomorphic spindled cells with hyperchromatic nuclei. Focal rosette formation is noted (hematoxylin and eosin stain; original magnification, ×10).