New staging system for sinonasal inverted papilloma in the endoscopic era

OBJECTIVES: Advanced endoscopic techniques have emerged as the preferred treatment modality for sinonasal inverted papilloma (IP); however, a staging system that provides prognostic information has not yet been developed. This study aims to develop a clinically relevant staging system for IP managed with the endoscopic approach as the primary surgical modality. DESIGN: A systematic review of the English-language literature (1985-2006) and a single institution's experience. METHODS: From the literature, 445 patients with IP treated by endoscopic resection were identified in 14 reports. Only patients with known IP sites and outcomes were included. RESULTS: Patients were categorized into three groups on the basis of recurrence rates (RR): group A (IP confined to the nasal cavity, ethmoid sinus, and medial maxillary sinus), 3.0% RR (n = 234); group B (IP with lateral maxillary sinus, sphenoid sinus, or frontal sinus involvement), 19.8% RR (n = 177); and group C (IP with extrasinus extension), 35.3% RR (n = 34). Pearson's chi-square test showed statistically significant differences for all pair-wise comparisons between groups (P < .05). Mean follow-up was 39.8 months. CONCLUSIONS: This new staging system for IP provides information about prognosis (as operationally defined by RR) for IP managed by advanced endoscopic techniques. In contrast, other staging systems for IP reflect surgeon's judgment rather than outcomes data. This new classification for IP provides important objective data for preoperative planning and patient counseling.