title: Preoperative staging and surgical approaches for sinonasal inverted papilloma.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Oikawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Furuta
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakamaru
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Oridate
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fukuda
mesh_terms: D000328:Adult; D000368:Aged; D004724:Endoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D013517:Otorhinolaryngologic Surgical Procedures / Q000379:methods*; D018308:Papilloma, Inverted / Q000473:pathology* / Q000601:surgery; D010255:Paranasal Sinus Neoplasms / Q000473:pathology* / Q000601:surgery; D011300:Preoperative Care / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome