Surgical Risk Factors for Recurrence of Inverted Papilloma

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1 The Laryngoscope VC 2015 The American Laryngological, Rhinological and Otological Society, Inc. Surgical Risk Factors for Recurrence of Inverted Papilloma David Y. Healy Jr., MD, CDR, MC, USN; Nipun Chhabra, MD; Ralph Metson, MD; Eric H. Holbrook, MD; Stacey T. Gray, MD Objectives/Hypothesis: To identify variations in surgical technique that impact the recurrence of inverted papilloma following endoscopic excision. Study Design: Retrospective cohort. Methods: Data from 127 consecutive patients who underwent endoscopic excision of inverted papilloma and oncocytic papilloma at a tertiary care medical center from 1998 to 2011 were reviewed. Patient demographics, comorbidities, tumor stage, and intraoperative details, including tumor location and management of the base, were evaluated to identify factors associated with tumor recurrence. Results: Recurrence of papilloma occurred in 16 patients (12.6%). Mean time to recurrence was 31.0 months (range, months). Mucosal stripping alone was associated with a recurrence rate of 52.2% (12/23 patients), compared to 4.9% (3/61 patients) when the tumor base was drilled, 4.7% (1/21 patients) when it was cauterized, and 0.0% (0/22 patients) when it was completely excised (P 5.001). Increased recurrence rate was associated with tumors located in the maxillary sinus (P 5.03), as well as the performance of endoscopic medial maxillectomy (P 5.001) and external frontal approaches (P 5.02). Conclusions: Drilling, cauterizing, or completely excising the bone underlying the tumor base during endoscopic resection reduces the recurrence rate of inverted and oncocytic papilloma, when compared to mucosal stripping alone. Surgeons who perform endoscopic resection of these tumors should consider utilization of these techniques when possible. Key Words: Inverted papilloma, Schneiderian papilloma, paranasal sinus tumor, endoscopic sinus surgery, risk factors. Level of Evidence: 4 Laryngoscope, 126: , 2016 INTRODUCTION Sinonasal inverted papilloma (IP) are benign neoplasms that demonstrate a slow but persistent growth pattern, can be locally destructive, and have potential for malignant transformation. Patients with IP typically present with unilateral nasal obstruction, but may have other symptoms such as rhinorrhea, hyposmia, epistaxis, or headache. 1 IPs derive from the Schneiderian membrane, which is the mucosal lining of the nasal passage and paranasal sinuses; thus, the more descriptive nomenclature for this lesion is Schneiderian papilloma, inverted type. The tumor has a distinct histologic appearance of a thickened epithelium that lacks mucous-secreting cells From the Department of Otolaryngology (D.Y.H.), Naval Medical Center Portsmouth, Portsmouth, Virginia; Department of Surgery (N.C.), University of Illinois College of Medicine, Saint Anthony Medical Center, Rockford, Illinois; Department of Otolaryngology (R.M., E.H.H., S.T.G.), Massachusetts Eye and Ear Infirmary, Boston, Massachusetts; Department of Otology and Laryngology (R.M., E.H.H., S.T.G.), Harvard Medical School, Boston, Massachusetts, U.S.A. Editor s Note: This Manuscript was accepted for publication August 19, The views expressed in this article are those of the author(s) and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the United States government. Research data were derived from a Massachusetts Eye & Ear Infirmary, Boston, Massachusetts, institutional review board protocol. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to David Y. Healy, Jr., MD, Department of Otolaryngology, Naval Medical Center Portsmouth, 620 John Paul Jones Circle, Portsmouth, VA dyhealy@hotmail.com DOI: /lary and has inverted into the underlying stroma. 2 A less common oncocytic type of Schneiderian papilloma has similar clinical presentation and behavior to IP, but has pseudostratified columnar epithelium containing eosinophilic cytoplasm on pathological examination. Optimal treatment of both inverted and oncocytic papilloma is complete surgical excision. The traditional external surgical approach of lateral rhinotomy with medial maxillectomy has given way to transnasal endoscopic resection. A systematic review of published series of IP excision demonstrated a recurrence rate of 12% for endoscopic approaches compared to 17% for external approaches. 3 A meta-analysis comparing contemporary endoscopic ( ) versus external approaches ( ) demonstrated an improved recurrence rate in the endoscopic group (12% vs. 20%, respectively). 4 Whether endoscopic or external approaches are used for access, the surgical principle is the same complete excision of the tumor is necessary to avoid recurrence. Incomplete excision of these tumors invariably leads to recurrence, typically within 3 years. 1 Modern surgical methods have managed to reduce, but not eradicate, recurrence of these tumors. Many studies have sought to identify risk factors for IP recurrence. One such risk factor appears to be tumor location. A systematic review of frontal sinus IPs demonstrated a recurrence rate of 22.4%. 5 It was postulated by the authors that the technical challenges of accessing the frontal sinus caused the higher recurrence rate in this location. Other reported risk factors for recurrence

2 TABLE I. Patient Demographics. Patients % of Total Recurrence P Total patients (12.6%) Gender Male (13.5%) NS Female (11.3%) NS Tobacco use History of smoking, quit (7.7%) NS Current smoker (10.0%) NS Tumor diagnosis Inverted papilloma (14.0%) NS Oncocytic papilloma (0.0%) NS IP with atypia/dysplasia (20.0%) NS Previous IP resection (14.9%) (4.0%) 2 or more (0.0%) Previous surgeries total* (13.3%) NS (14.2%) 2 or more (6.3%) *Includes all previous sinus surgeries. IP 5 inverted papilloma; NS 5 not significant. include tobacco 6 ; histologic parameters including hyperkeratosis, hyperplasia, and mitotic index 7 ; and certain histochemical markers. 1 Traditionally, tumor control was thought to be achieved by stripping all mucosa within the involved sinuses. 8 An unproven but compelling surgical principle aimed at lowering recurrence rates is to achieve a deep oncologic margin by drilling or removing the underlying bone at the site of tumor attachment (i.e., the tumor base). Evidence that this surgical maneuver may be important is suggested from a pathologic analysis of the bone at the base of IPs. In one study, Chiu et al. found mucosal tissue to be embedded within a bony crevice in two of nine (22.2%) surgical IP specimens. 9 Despite the theoretical advantage of using a drill or other ablative method along the IP base during surgery, these techniques have yet to be shown to reduce tumor recurrencerates.thepurposeofthisstudywastodetermine whether or not the use of such methods intended to enhance surgical control of the deep tumor margins do, in fact, impact the rate of IP recurrence following endoscopic resection. MATERIALS AND METHODS A retrospective analysis was conducted of all surgeries (n 5 135) performed to remove sinonasal inverted or oncocytic papillomas by three rhinologists (R.M., E.H.H., S.T.G..) at the Massachusetts Eye & Ear Infirmary (MEEI) from January 1998 through February Complete endoscopic excision or hybrid endoscopic/external approaches were utilized for all surgeries. Patients underwent at least 3 years of endoscopic tumor surveillance after surgery (mean length of follow-up 8.1 years). For the purpose of simplicity, inverted papilloma is used to mean both inverted and oncocytic papilloma unless otherwise specified. Exclusion criteria included: 1) surgeries that were known to be incomplete excisions at the conclusion of the procedure (n 5 3), 2) surgeries for malignant lesions or the presence of malignancy in pathologic specimen (n 5 1), 3) insufficient documentation (n 5 2), 4) no IP found in the pathologic specimen (n 5 1), 5) suspected but unproven recurrence due to loss of follow-up (n 5 1). In three cases, surgery was staged, because of the unexpected need for an external approach (n 5 1) or excessive blood loss (n 52). These staged procedures were treated as one surgery, with the higher estimated blood loss (EBL) used for statistical analysis. Surgical risk factors analyzed included method of tumor base deep margin control (drilling, removal, cauterization, or stripping of overlying mucosa alone), location of tumor, location of tumor base (as detailed in the operative report), previous surgeries, EBL, presence of bilateral polyps, and use of image guidance. If the operation report did not give the location of the tumor base, the location of the base was annotated as not detailed, and analyzed as a potential risk factor. Additional risk factors analyzed are given in Tables I and II. Four methods were utilized for surgical management of the tumor base: 1) mucosal stripping alone, 2) drilling the tumor base, 3) cauterization of the tumor base, or 4) completely resecting the tumor base (i.e., septectomy, middle turbinectomy, or removal of the lamina papyracea when the tumor is based on bony structures that can be completely excised). Description of Statistical Methods Statistical analyses were performed using R software (R Foundation for Statistical Computing, Vienna, Austria). A stepwise multivariate logistic regression model was created with the binary outcome defined as no recurrence or recurrence of IP. Both the Fisher exact test and logistic regression analysis were used to analyze the effect of the various surgical risk factors. Institutional review board approval for this study was given by the Human Study Committee of the MEEI. RESULTS The study population consisted of 127 patients with a mean age of 56.9 years (range, ) as shown in Table I. Previous sinonasal surgery was performed prior to the diagnosis of IP in 65 (51.2%) patients. Previous surgery for a known diagnosis of IP was performed by outside surgeons in 32 (25.2%) patients. Forty-five patients (35.4%) had no prior history of endoscopic sinus surgery. The most common presenting symptom was nasal obstruction (63.3%), whereas 24.2% of patients were asymptomatic, with IP as an incidental finding on imaging or endoscopy. Other presenting symptoms included rhinorrhea/postnasal drip (8.7%), epistaxis (8.7%), pain or pressure (8.7%), sinusitis (7.9%), hyposmia (4.7%), visual disturbance (2.3%), and facial swelling (1.5%). Tumors were most commonly located (but not necessarily based) in the nasal cavity (58.3%), followed by the maxillary sinus (46.5%), the ethmoid sinuses (41.7%), the frontal sinus (17.3%), and the sphenoid sinus (11.0%). The tumor base (or the site of tumor attachment) was widely dispersed throughout the paranasal sinuses, with the classically reported location for IP based along the lateral 797

3 TABLE II. Location of Tumor and Base of Tumor. Patients % of Total Recurrence P Tumor location Nasal cavity (9.5%) NS Ethmoid sinus (17.0%).088 Maxillary sinus (16.9%).033 Sphenoid sinus (7.1%) NS Frontal sinus (15.3%) NS Tumor base location Nasal cavity Total (5.6%) NS Septum (0.0%) NS Lateral nasal wall (8.3%) NS Ethmoid cavity Total (7.5%) NS Uncinate (0.0%) NS Lateral Wall (12.5%) NS Turbinate (6.7%) NS Anterior sphenoid face (0.0%) NS Roof (0.0%) NS Maxillary sinus Total (10.7%) NS Anterior wall (6.7%) NS Posterior wall (9.1%) NS Medial wall (25.0%) NS Lateral wall (0.0%) NS Superior wall (8.0%) NS Floor (25.0%) NS Sphenoid sinus Total (0.0%) NS Anterior/inferior wall (0.0%) NS Posterior/superior wall (0.0%) NS Lateral wall (0.0%) NS Medial wall (0.0%) NS Frontal sinus Total (15.4%) NS Posterior wall (11.1%) NS Anterior wall (0.0%) NS Medial wall (0.0%) NS Interfrontal cell (0.0%) NS Floor (36.7%).032 Supraorbital cell (0.0%) NS Not detailed (62.5%).013 NS 5 not significant. nasal wall only occurring in 9.4% of patients in this series (Table II). All surgeries included a transnasal endoscopic approach (Table III). Thirty-nine patients (30.7%) underwent additional external procedures (Caldwell-Luc, external trephine, or osteoplastic flap without obliteration). Mean EBL was ml (range, 10 1,350 ml, standard deviation ml). Twenty-seven patients (21.2%) experienced complications, which included facial numbness (6.3%) and frontal stenosis (5.5%). Uncommon complications included cerebrospinal fluid (CSF) leak, acute sinusitis, epistaxis, diplopia, facial cellulitis, sublabial hematoma, mucocele formation, and epiphora, which occurred in one or two patients each. Tumor recurrence occurred in 16 patients (12.6%) as shown in Table IV. Fifteen patients had recurrence of benign IP, and one patient had a malignant conversion to Schneiderian carcinoma. The average time from surgery to recurrence was 27 months (range, months). Of the 15 patients with benign tumor recurrence, 12 underwent one revision surgery, and one underwent three revision surgeries. Both the patient with malignant transformation and the patient requiring multiple revision surgeries had extensive tumor involvement of the frontal sinus. Mucosal stripping alone without drilling, cauterizing, or removing the bone underlying the tumor base was associated with a recurrence rate of 52.2% (12/23 patients), compared to 4.9% (3/61) in patients where the TABLE III. Surgical Details. Total % of Total Recurrences P Surgery performed Frontal drillout (Draf III) (14.3%) NS Medial maxillectomy (26.7%).005 Denker s procedure (0.0%) NS Caldwell-Luc (13.7%) NS Trephine or osteoplastic flap (23.5%).024 Status of tumor base Mucosa stripped (52.2%).001* Bone removed (0.0%) Bone drilled (4.9%) Bone cauterized (4.8%) Surgical details Staged surgery (0.0%) Image guidance used (14.7%) Mucosal margins Not confirmed (6.8%) NS Confirmed negative (20.4%) NS Presence of polyps None (11.1%) NS Unilateral (17.7%) Bilateral (50.0%) Tumor stage A (13.7%) NS B (10.8%) C (50.0%) Lund-Mackay CT score < (10.5%) NS (9.6%) NS *Significance compared to drilling, cauterization, and removal combined. Margins achieved with intraoperative frozen section analysis. Staging system for inverted papilloma (Cannady 2007). 14 CT 5 computed tomography; NS 5 not significant. 798

4 TABLE IV. Patients With Tumor Recurrence (n 5 16). Age (yr)/gender Type Location of Tumor Location of Base Surgery Performed Recurrence (mo) 46/male IP NC, E, M Max sinus medial wall ESS, MM /female IP M Not detailed ESS, MM /male IP M Not detailed ESS, MM /female IP NC, E, M Not detailed ESS, MM /male IP M Max sinus medial and ESS, MM, CL 76.0 superior wall 69/male IP E, F Frontal sinus floor, ethmoid ESS, trephine 6.3 lateral wall 21/male IP NC, S Not detailed ESS /male IP E, F Frontal sinus floor and posterior wall ESS, Draf III, trephine 43/female IP M Max sinus medial wall and floor ESS, MM, CL /female IP NC, E Lateral nasal wall ESS, MM /male IP E, F Frontal sinus floor, ethmoid lateral wall ESS, Draf IIB, trephine 50/male IP, atypia E, F Frontal sinus floor ESS, trephine /female IP NC, M Max sinus medial wall ESS, MM /female IP NC, E, M Not detailed ESS, CL /male IP E, M Max sinus anterior and ESS 5.5 superior wall 52/male IP NC, M Max sinus posterior wall, lateral nasal wall ESS 7.3 Listed in chronological order. CL 5 Caldwell-Luc; E 5 ethmoid sinus; ESS 5 endoscopic sinus surgery; F 5 frontal sinus; IP 5 inverted papilloma; M 5 maxillary sinus; MM 5 medial maxillectomy; NC 5 nasal cavity; S 5 sphenoid sinus tumor base was drilled, 4.7% (1/21) in patients whose tumor base was cauterized, and 0.0% (0/22) for patients whose tumor base was removed (P 5.001) as shown in Figure 1. In those patients for whom the operative report did not specify the location of the tumor base, the risk of recurrence was significantly higher (62.5%, 5/8 patients, P 5.013). All of these patients underwent a mucosal stripping procedure. Fig. 1. Inverted papilloma recurrence rate versus technique use to treat tumor base. Kaplan-Meier survival curves demonstrate variation in inverted papilloma recurrence rate depending on the surgical technique used to treat the bone at the base of the tumor. Patients whose tumor base was treated by mucosal stripping alone (no action) had a significantly higher recurrence rate. Location of tumor in the maxillary sinus, as compared to the nasal cavity or other paranasal sinuses, was associated with an increased risk of recurrence (10/59 patients, 16.9%, P 5.024). Location of tumor within the frontal sinus was not associated with a higher rate of recurrence; however, tumor base location along the floor of the frontal sinus was associated with an increased rate of recurrence of 36.4% (4/11 cases, P 5.032). No other tumor base locations were associated with a statistically significant increase in recurrence rate. An increased incidence of tumor recurrence was also found for patients who underwent endoscopic medial maxillectomy (8/30 patients, 26.7%, P 5.005), and external frontal procedures (4/17 patients, 23.5%, P 5.020) for treatment of their papilloma. The recurrences in the external frontal approach group were observed only in those who had an external trephination (4/14 cases), whereas no recurrences occurred in those who underwent osteoplastic flap approaches without obliteration (0/3 cases). Increasing EBL was associated with increased risk of recurrence, with an odds ratio of per milliliter of blood loss (P 5.009). Increasing age was associated with a reduced risk of recurrence. The average age of the population with recurrence was 52.0 years old compared to an age of 57.6 years old in the population without recurrence (P 5.04). Higher tumor stage and presence of either the tumor or tumor base within the frontal or sphenoid sinus did not significantly impact recurrence rate. The intraoperative confirmation of negative mucosal margins 799

5 by frozen section also did not improve recurrence rates. Other factors including gender, smoking status, previous surgeries, comorbidities, computed tomography stage, presence of atypia or oncocytic papilloma on histology, use of image guidance, and presence of inflammatory polyps did not significantly influence recurrence rate. DISCUSSION Although drilling of bone at the base of sinonasal IP to achieve oncologic margins has been advocated by several authors, 1,9 the current study is the first to demonstrate a reduction in tumor recurrence with this technique. The manner in which the tumor base was treated had a marked influence on recurrence rate, with drilling, cauterization, or removal of all bone at the tumor base achieving recurrence rates less than 5%. Surgeries that did not specifically address the bone at the tumor base (i.e., mucosal stripping alone) had a significantly higher recurrence rate (52.2%) and accounted for the majority of recurrences. A possible explanation as to why drilling, cauterizing, or removing the bone underlying the tumor base is important is the presence of rests of abnormal epithelium or frank tumor embedded within the bone that cannot be removed by mucosal stripping alone. 9 Another possibility is that surgical manipulation of the bony tumor base required that the surgeon isolate the tumor base carefully and methodically, thus enhancing the surgeon s ability to appreciate the entire extent of the tumor. Complete removal of bone at the tumor base was associated with no recurrences. This method was utilized when practical, for example, if the tumor base was found to be pedicled on the middle turbinate, superior turbinate, or uncinate process. In such cases, the underlying bone could be removed with little or no patient morbidity. Even in those cases where the tumor was based on the lamina papyracea, an orbital decompression procedure without incising the underlying periorbita led to complete tumor eradication. Cauterization was typically utilized in areas where, in the surgeon s estimation, drilling or removal of bone at the tumor base was not easily performed, such as at the skull base, where there was an increased risk of CSF leak with more significant manipulation of the tumor base. Similar to drilling, cauterization of the base is thought to destroy potential diseased epithelium embedded in the bone, which could result in recurrent tumor. In this study, tumor location within the frontal sinus was not associated with a higher rate of recurrence. However, a significantly higher rate of papilloma recurrence occurred in patients whose tumor base was located along the floor of the frontal sinus (Table II). Also, the performance of external frontal procedures was associated with a higher tumor recurrence rate (all recurrences occurred with external trephine approach). These findings correlate well with the several reports of higher recurrence rate association with frontal sinus IP. A recent systematic review analyzing the published recurrence rates of frontal sinus IP found the rate to be 22.4%, well above the overall rate of 13% in modern 800 series. 10 Numerous authors have attributed this higher rate to the technical difficulty in accessing the frontal sinus. 5,10 The floor of the frontal sinus is the most difficult to visualize and instrument via an endoscopic approach, 11 and can pose a surgical challenge even when a frontal trephination approach is added. Optimal surgical access to the lateral aspect of the frontal floor is best achieved with an osteoplastic flap approach, which provides direct visualization. This study demonstrated an increase in recurrence rate for tumors located within the maxillary sinus (16.9%). This finding correlates with the IP staging systems of Krouse, 12 Han, 13 and Cannady 14 that assign a higher stage to tumors of the lateral maxillary sinus due to increased difficulty in visualizing and removing these tumors via a transnasal endoscopic approach. Endoscopic medial maxillectomy procedures were also associated with a significantly higher recurrence rate (26.7%). This finding may be explained by the fact that these procedures were commonly performed in conjunction with mucosal stripping procedures and in surgeries where the base location was not detailed in the operative report, both of which were associated with high recurrence rates; therefore, it is difficult to ascertain the importance of endoscopic medial maxillectomy as an independent risk factor. Medial maxillectomy has been considered a viable surgical option for IP tumor removal since it was demonstrated to improve recurrence rates prior to the advent of endoscopic techniques. 1,8 The authors believe that a medial maxillectomy should now be utilized only if it facilitates removal of the tumor base, such as in cases when it is attached to the medial maxillary sinus wall. In this study, EBL was found to be a statistically significant predictor of IP recurrence. Increased intraoperative bleeding diminishes endoscopic visualization 15 and would be expected to increase the difficulty of defining and excising the tumor base. The IP tumor staging system proposed by Cannady et al. 14 was selected for statistical analysis in this study, because unlike other proposed papilloma staging systems, it has been shown to correlate with risk of tumor recurrence. Nevertheless, in this series, increased Cannady stage was not found to be associated with an increased rate of recurrence. This finding may reflect the relatively small size of the study population, as well as the presence of only two patients with stage C tumors. Another intriguing finding of this study was the paucity of tumors found to be based along the lateral nasal wall, which is classically taught as the most common site of origin for IPs. If endoscopic medial maxillectomy were to excise tumors that are based only along the lateral nasal wall, including the uncinate process, inferior turbinate, and medial wall of the maxillary sinus, then approximately 25% of the tumors, according to this series, would be expected to be completely excised. The remaining 75% of tumors had attachment to paranasal surfaces not removed with this approach. Because of this finding, the authors recommend that use of the term lateral nasal wall as the most common site of IP attachment be reconsidered. Furthermore, endoscopic surgery can and should be individualized so that

6 tumor removal, including treatment of the bone at the tumor base, reflects the extent and location of the papilloma. Weaknesses of this study include its retrospective design and its analysis of three surgeons whose varying nuances of surgical technique may affect recurrence rates. In addition, although the study population is relatively large from the perspective of the rarity of these tumors, it remains small from the perspective of robust statistical analysis. CONCLUSION This study is the first to demonstrate a reduction in the tumor recurrence rate when bone at the base of an IP is drilled, removed, or cauterized during endoscopic resection. The performance of a mucosal stripping procedure alone without addressing the underlying bone is not recommended during endoscopic resection of these neoplasms. BIBLIOGRAPHY 1. Anari S, Carrie S. Sinonasal inverted papilloma: narrative review. J Laryngol Otol 2010;124: Barnes L, Tse LLY, Hunt JL. Schneiderian papillomas. In: Barnes L, Eveson JW, Reichert P et al., eds. World Health Organization Classification of Tumours. Pathology and Genetic of Head and Neck Tumours. Lyon, France: IARC Press; 2005: Karkos PD, Fyrmpas G, Carrie SC, Swift AC. Endoscopic versus open surgical interventions for inverted nasal papilloma: a systematic review. Clin Otolaryngol 2006;31: Busquets JM, Hwang PH. Endoscopic resection of sinonasal inverted papilloma: a meta-analysis. Otolaryngol Head Neck Surg 2006;134: Walgama E, Ahn C, Batra PS. Surgical management of frontal sinus inverted papilloma. Laryngoscope 2012;122: Jardine AH, Davies GR, Birchall MA. Recurrence and malignant degeneration of 89 cases of inverted papilloma diagnosed in a non-tertiary referral population between 1975 and 1995: clinical predictors and p53 studies. Clin Otolaryngol Allied Sci 200;25: Katori H, Nozawa A, Tsukuda M. Histopathological parameters of recurrence and malignant transformation in sinonasal inverted papilloma. Acta Otolaryngol 2006;126: Weissler MC, Montgomery WW, Turner PA, Montgomery SK, Joseph MP. Inverted papilloma. Ann Otol Rhinol Laryngol 1986;95: Chiu AG, Jackman AH, Antunes MB, Feldman MD, Palmer JN. Radiographic and histologic analysis of the bone underlying inverted papillomas. Laryngoscope 2006;116: Walgama E, Ahn C, Batra PS. Surgical management of frontal sinus inverted papilloma. Laryngoscope 2012;122: Timperley DG, Banks, C, Robinson D, Roth J, Sacks R, Harvey RJ. Lateral frontal sinus access in endoscopic skull-base surgery. Int Forum Allergy Rhinol 2011;1: Krouse JH. Development of a staging system for inverted papilloma. Laryngoscope 2000;110: Han JK, Smith TL, Loehrl T, et al. An evolution in the management of sinonasal inverting papillomas. Laryngoscope 2001;111: Cannady SB, Batra PS, Sautter NB, Roh HJ, Citardi MJ. New staging system for sinonasal inverted papilloma in the endoscopic era. Laryngoscope 2007;117: Stankiewicz JA. Complications of endoscopic intranasal ethmoidectomy. Laryngoscope 1987;97: