Preoperative staging and surgical approaches for sinonasal inverted papilloma

Objectives: We sought to determine the value of preoperative staging by magnetic resonance imaging (MRI) assessment in the surgical management of sinonasal inverted papillomas (IPs). Methods: Preoperative MRI staging was used to assess 22 patients with IPs. In addition to the Krouse staging system, T3 cases were categorized as subgroup T3-B if tumors extended into the frontal sinus or the supraorbital recess; otherwise, they were categorized as T3-A. Standard endoscopic sinus surgery (ESS) was the first choice for T1 and T2 cases. Endoscopic approaches, including ESS combined with endoscope-assisted transantral approach and endoscopic medial maxillectomy, were considered in T3-A cases, and external approaches were considered in T3-B cases. Patients were followed for a minimum of 1 year after surgery. Results: Preoperative MRI staging and postoperative staging were coincident in 21 of the 22 patients (95%). All 8 T2 cases were treated by an endoscopic approach. Of 10 T3-A cases, 9 (90%) were treated by an endoscopic approach and 1 (residual case) was treated by an external approach. All 3 of the T3-B cases underwent an external approach. One T4 case with malignant transformation underwent an external approach followed by radiotherapy. After a median follow-up period of 22 months, none of the 22 patients had had a recurrence. No major complications were observed after endoscopic approaches, but epiphora or hemorrhage requiring transfusion occurred in 3 of the 5 patients (60%) who underwent external approaches. Conclusions: Preoperative staging of IP by MRI is useful for selecting cases that can be managed by endoscopic approaches, resulting in lower rates of tumor recurrence and morbidity.