BACKGROUND: The pathogenesis of inverted papilloma (IP) has not been fully elucidated. However, chronic paranasal sinus inflammation has been anecdotally observed in sites distant from tumor obstruction in IP patients, suggesting an association between inflammation and IP tumorigenesis. This study assesses the association between sinonasal inflammation found in IP and compares this to the level of inflammation observed in other sinonasal tumors. METHODS: A retrospective chart review was performed identifying patients with unilateral IP. Pertinent clinical data was obtained and comparative analysis of preoperative computed tomography (CT) imaging and histopathology was performed. A sample of unilateral, sinonasal, non-IP and non-squamous cell tumors was used as the control. The Lund-Mackay scoring system was used to assess radiologic sinonasal inflammation both ipsilateral and contralateral to the tumor. RESULTS: Seventy-one patients were included; 58.9% of patients with IP had evidence of contralateral sinusitis at the time of presentation. In the control group, 26.7% had evidence of contralateral inflammation. When comparing contralateral sinus inflammation between the 2 study groups, the IP patients had significantly higher Lund-Mackay scores than the control group (1.9 vs 0.26, p < 0.001). When comparing ipsilateral sinus inflammation, no significant difference was found in Lund-Mackay scores (5.44 vs 4.00, p < 0.184). CONCLUSION: In this study, unilateral IPs were associated with a higher level of contralateral sinonasal inflammation when compared to control. This suggests that IP may be associated with inflammation that is independent of obstruction by the tumor. Further studies are needed to better understand the temporal relationship between chronic inflammation and tumorigenesis.
BACKGROUND: The pathogenesis of inverted papilloma (IP) has not been fully elucidated. However, chronic paranasal sinus inflammation has been anecdotally observed in sites distant from tumor obstruction in IP patients, suggesting an association between inflammation and IP tumorigenesis. This study assesses the association between sinonasal inflammation found in IP and compares this to the level of inflammation observed in other sinonasal tumors. METHODS: A retrospective chart review was performed identifying patients with unilateral IP. Pertinent clinical data was obtained and comparative analysis of preoperative computed tomography (CT) imaging and histopathology was performed. A sample of unilateral, sinonasal, non-IP and non-squamous cell tumors was used as the control. The Lund-Mackay scoring system was used to assess radiologic sinonasal inflammation both ipsilateral and contralateral to the tumor. RESULTS: Seventy-one patients were included; 58.9% of patients with IP had evidence of contralateral sinusitis at the time of presentation. In the control group, 26.7% had evidence of contralateral inflammation. When comparing contralateral sinus inflammation between the 2 study groups, the IP patients had significantly higher Lund-Mackay scores than the control group (1.9 vs 0.26, p < 0.001). When comparing ipsilateral sinus inflammation, no significant difference was found in Lund-Mackay scores (5.44 vs 4.00, p < 0.184). CONCLUSION: In this study, unilateral IPs were associated with a higher level of contralateral sinonasal inflammation when compared to control. This suggests that IP may be associated with inflammation that is independent of obstruction by the tumor. Further studies are needed to better understand the temporal relationship between chronic inflammation and tumorigenesis.