Primary aneurysmal bone cyst of the maxillary sinus in a child: case report and review of the literature.

Our case report describes a primary aneurysmal bone cyst (ABC) of the maxillary sinus in a 12-year-old girl. The young patient presented with progressive diplopia, strabismus, and rapidly growing painless swelling of the left cheek. Imaging studies showed a heterogeneous contrast enhancing mass expanding the left maxillary sinus. The lesion was completely resected endoscopically and histological examination reported it as an ABC. The patient recovered well and is free of recurrence 9 months following surgery. ABC is a benign lesion usually associated with other bone pathology (fibrous dysplasia). It may behave aggressively and invade the orbit; so resection is necessary. Minimally invasive techniques such as endoscopic sinus surgery can be performed successfully in select cases. Long follow up is important because recurrence may occur, in which case further resection is warranted.