Surgical management of inverted papilloma involving the frontal sinus: a practical algorithm for treatment planning

Inverted papilloma of the frontal sinus is a challenging disease. Given its rarity, only small case series are present in the literature. The objectives of the present study are to review our experience in the surgical management of inverted papillomas involving the frontal sinus and to propose a practical algorithm for selecting the most appropriate approach. Data on patients affected by inverted papilloma involving the frontal sinus and surgically treated between 2002 and 2016 were collected. The type of involvement of frontal sinus and extent of surgery performed (endoscopic endonasal, external or combined approaches) were analysed. A brief review of consistent literature was also carried out. Forty-seven consecutive patients were treated using an exclusive endoscopic endonasal approach (EEA) in 18 cases, while a combined endonasal with external osteoplastic approach was required in 29 cases. Most patients (29/47, 62%) had been treated previously, mainly by an endoscopic approach. A single intraoperative complication occurred (1/47, 2%), i.e. cerebrospinal fluid (CSF) leak, that was successfully repaired intraoperatively without any consequences. Recurrences were observed in only 2/47 cases (4%) after a mean follow-up of 43 months (range, 12-137). The management of inverted papilloma involving the frontal sinus requires great expertise and the surgical technique should be tailored to the site of attachment of the tumour, its extension and the anatomical conformation of each frontal sinus. The encouraging results obtained in this case series support the use of this practical treatment algorithm.