Factors affecting recurrence of sinonasal inverted papilloma.

The aim is to study clinical characteristics and recurrence rates for sinonasal inverted papilloma (NIP), to evaluate relevant factors for its recurrence, and to compare the curative rates of different surgical approaches. The Krouse classification for the 156 follow-up cases of the patients with NIP was as following: 26 cases in T1, 33 cases in T2, 94 cases in T3, and 3 cases in T4. A total number of 99 cases of endoscopic sinus surgery were included, of which 26 cases of lateral rhinotomy approach were combined with Caldwell Luc approach, and 31 cases of nasal endoscopy combined with traditional surgery, with average postoperative follow-up of 3-11 years. Of the 156 studied patients with NIP, male:female = 1.69:1, age varied from 18 to 77 years, with average of 56 years, 19 cases showed postoperative recurrence, of which 8 cases developed to be squamous cell carcinoma. Among these 8 cases, 3 patients showed no recurrence after treatment in 5 years, and the other 5 patients died in 3-2 years period. Tumor recurrence rates for different surgical approach are: 9.09 % for endoscopic surgical group, 23.08 % for traditional surgical group, and 12.12 % for combined surgical group; tumor malignancy rates for different surgical approach are: 2.02 % for endoscopic surgical group, 11.54 % traditional surgical group, and 9.09 % for combined group, and Chi-square test showed that the differences in recurrence and malignancy rates for NIP patients with different surgical treatments were not statistically significant (P > 0.05). Recurrence rates for different stages are: T1 at 3.85 %, T2 at 12.12 %, T3 at 14.89 %, and T4 at 0.00 %, and the differences in the recurrence rates for different stages were not statistically significant (P > 0.05) by Chi-square test. There are clear clinical features for NIP, and the recurrence is related to the thoroughness of the first time surgical removal of lesions and is less relevant with Krouse classification stage and surgical approaches.