Proactive Approach to Surveillance of Sinonasal Inverted Papilloma

Background Inverting papilloma (IP) is a benign and rare tumor of the paranasal sinuses, accounting for 0.5 to 4.0% of all sinonasal neoplasms. IP differs from other benign sinonasal neoplasms in its high rate of recurrence and potential for late malignant transformation. There is no consensus regarding optimal postoperative surveillance.

Objective To describe the approach to surveillance of IP at one tertiary medical center.

Methods The medical records of patients with biopsy-proven IP treated between 2000 and 2016 were retrospectively reviewed.

Results A total of 144 patients were included, 6 of who presented for management of recurrent IP initially managed elsewhere; these patients did not have previous scheduled follow-up. Ten patients (6.9%) had undergone malignant degeneration at the time of presentation. All patients underwent initial operative management. Postoperative follow-up consisted of debridement at 1 week, 2 weeks, and 1 month postoperatively. Postoperative CT imaging was obtained 4 months after initial resection. After the first year, follow-up visits were graduated to yearly visits.

A total of 58 patients were taken to the operating room for a “second look” procedure based on suspicious endoscopic or imaging findings. These were performed at an average of 19 months (range: 1–168 months) after initial resection. Of these, 21 (36%) had negative biopsies and 37 patients (27.6%) were found to have persistent disease, identified at an average of 16 months (range: 1–168). Two of these patients had malignant degeneration, one at 4 months and one at 25 years after initial resection. Fourteen of the 37 patients were again taken back to the operating room for a “third look,” 10 of whom were found have further persistent disease. Five patients were found on three or more occasions to have persistent disease.

Discussion Classical approaches to IP involved radical oncologic resections with the goal of preventing recurrence. Purely endoscopic approaches have been embraced because of their minimally invasive nature. However, in spite of the benign nature of IP, a less aggressive approach to resection carries an inherent risk of leaving residual disease. In our series, a significant number of patients under surveillance for benign IP were found to have persistent disease based on operative biopsy. Patients were followed up frequently after initial resection, allowing for early identification and biopsy. In our series, recurrences occurred most often within the first 18 months, suggesting this early period warrants particular vigilance. We attribute our higher apparent “recurrence” rate compared with published estimates numbers on our aggressive approach to management surveillance of sinonasal inverted papilloma. Likewise, our low rate of malignant degeneration is likely due to a low threshold for early operative intervention. Our data suggest that the current practice of follow-up for IP is likely inadequate, and published numbers may overestimate cure rates. Taken together, our series supports the use of minimally invasive initial resections, with a low threshold for “second look” procedures to identify disease persistence.

Conclusion A proactive approach to surveillance including frequent postoperative evaluations and early operative biopsy is indicated with the goal of decreasing disease recurrence and malignant degeneration.