Aneurysmal bone cyst of the frontal sinus.

Aneurysmal bone cysts are benign, vascular, cystic osseous tumors. Approximately 2% of all aneurysmal bone cysts are found in the head and neck region, with the most common site being the mandible. We report a case of an aneurysmal bone cyst arising from the frontal sinus in a pediatric patient. The diagnosis was suggested through various radiographic studies, with the final pathologic diagnosis confirmed after tumor excision. Complete en-bloc excision was performed by using a bifrontal craniotomy approach, with immediate reconstruction of the defect by using a split calvarial bone graft.