Two Cases of Frontal Sinus Inverted Papilloma Treated With a Combined Bifrontal Craniotomy and Endonasal Endoscopic Approach.

An inverted papilloma of the frontal sinus is a challenging lesion for surgeons, for both anatomical and pathological reasons. Despite the trend away from an external approach and towards an endonasal endoscopic approach, indications for an external approach remain. The options for an external approach include endoscopic frontal trephination, transpalpebral orbital craniotomy, a supraorbital transeyebrow approach, an osteoplastic flap, and bifrontal craniotomy with cranialization. Each approach has advantages and disadvantages. Deciding on the appropriate approach is important for the patient's prognosis and risk of complications. We report two cases of frontal sinus inverted papilloma treated with a combined bifrontal craniotomy with cranialization and endonasal endoscopic approach. We also present a general review of the external approaches mentioned above.