Predicting the site of attachment of sinonasal inverted papilloma.

Statement of problem Sinonasal inverted papilloma is a benign, epithelial neoplasm, which has a propensity for malignant transformation and recurrence. The evolution of endoscopic trans-nasal surgery has facilitated less destructive and, more functionally and cosmetically acceptable approaches to this tumour. Recurrence rates have been shown to be more favourable than after traditional external approaches. Precise surgery is enhanced by pre-operative localisation of the site of tumour attachment. The aim of this study was to examine, in a prospective fashion, the predictive value of osteitis on the pre-operative CT scan of the paranasal sinuses at correctly identifying the site of attachment of sinonasal inverted papilloma. Method of study Pre-operative CT scans of the paranasal sinuses in 24 patients with histology-proven sinonasal inverted papilloma were examined for osteitis, allowing a prediction of the site of attachment. Coronal reformats of thin-cut (1mm) axial CT scans were evaluated. Intra-operatively, the actual site of tumour attachment was established. A correlation between the predicted and actual site of tumour attachment was calculated. Main result The predictive value of the osteitis sign was 95%. Principal conclusion Pre-operative identification of osteitis can be used in 95% of cases to accurately predict the intra-operative site of attachment of sinonasal inverted papilloma.