Of course, we ended up doing 3 more cases-patients that arrived at the last minute. The last case was a 69 year-old woman with a large tumor of the cheek. The tumor was located under the superior aspect of masseter muscle and had eroded into the lateral wall of the  maxillary sinus, partially eroding the lateral and inferior walls of the orbit and destroying the zygomatic arch. The tumor filled the maxillary sinus but appeared encapulated, suggesting it grew into the sinus rather than from the sinus. This was a very interesting and technically challenging surgery. We approached the mass from a parotid type incision. We were able to completely resect the tumor.  It was not clear where this tumor originated.

From this diagram, it is apparent how this tumor could cause the damage described. The aponeurotic portion of the muscle arises from the area of the zygomatic arch, and is near the orbit and the lateral maxillary wall.