ABSTRACT
<p><b>OBJECTIVE</b>To investigate malignant transformation of sinonasal inverted papilloma (SIP) treated by nasal endoscopic and endoscopy-assisted surgery.</p><p><b>METHODS</b>Seven cases with malignant transformation of SIP treated by nasal endoscopic and endoscopy-assisted surgery from February 2001 to December 2010 were reviewed. Followed-up time after surgery for each case was over 3 years. All cases were unilateral disease and at grade IV according to the SIP grading standards of Krouse. One case was T2, five T3, and one T4. The surgery were performed under general anaesthesia or local and strengthen anaesthesia. Postoperative radiotherapy was applied, with the doses of 60 - 70 GY.</p><p><b>RESULTS</b>All cases were squamous cell carcinoma confirmed pathologically after surgery. The patients were followed up with endoscopic examination for 3 - 5 years. Of 7 cases, recurrent disease occurred in 3 years after operation, but no recurrence in other 4 cases.</p><p><b>CONCLUSIONS</b>Nasal endoscopic and endoscopy-assisted surgery can be used in the treatment for the malignant transformation of SIP, with the advantages of minimally invasion, fewer complications and the well-preserved nasal functions. Application of radiotherapy after surgery could improve long-term survival efficacy of the patients.</p>