Inverted papilloma of the nasal cavity and paranasal sinuses: a Korean multicenter study

The study group for sinonasal tumors at the Korean Rhinologic Society analyzed the results of the Korean multicenter experience for sinonasal inverted papilloma (IP) surgeries.

Multicenter cohort study and retrospective analysis.

In total, 939 patients diagnosed with sinonasal IP treated between 1998 and 2007 at 17 university hospitals were enrolled. Demographic data and information about previous surgeries, the origin and involved site of the tumor, the surgical approach, follow-up duration, recurrence, and the presence of malignancy were collected. There were 361 patients whose follow-up was <12 months who were excluded, and 578 patients were included for recurrence analysis.

The mean follow-up duration for recurrence analysis was 41.0 months, and 15.7% (91/578) had recurrences, with a mean time to recurrence of 32.6 months. However, the group whose follow-up was longer than 3 years had a higher chance of tumor recurrence. Patients whose IPs involved the frontal sinus or the medial wall of the maxillary sinus had higher recurrence rates. There was no significant difference in recurrence rates according to stage or surgical approach. In the T3 stage of Krouse, the T3-A stage of Furuta, and group B of the Citardi staging system, the endoscopic approach alone resulted in higher recurrence rates.

Generally, there were no significant differences in recurrence rates according to clinical stage or surgical approach. Given the rate of delayed recurrence, follow-up of >3 years is required. Moreover, surgeons should always consider combined approaches to reduce the chances of recurrence.