Inverted papilloma of the sphenoid sinus: risk factors for disease recurrence

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Extended sphenoidotomy combined with transpterygoid approach for sphenoidal sinus inverted papilloma

PURPOSE

Inverted papilloma of the sphenoid sinus (IPSS) is a rare tumor with debated surgical management due to its proximity to vital structures. The aim of this manuscript is to highlight the role of a transpterygoid approach (TPA) and pedicle-orientated strategy in case of involvement of critical structures in IPSS and compare it with data from the literature.

METHODS

Patients with primary IPSS between January 2000 and June 2021 were included. Pre-operative CT/MRI were analyzed to classify the pneumatization of the SS and predict the insertion point of the inverted papilloma. All patients were treated with a trans-sphenoidal approach which was combined with a TPA in case of lateral insertion point. A systematic search was also performed to summarize the available literature.

RESULTS

Twenty-two patients were treated for IPSS. By CT, the SS was categorized with type III pneumatization in 72.8% of cases. Eleven patients (50%) were treated with a TPA with a statistical association with the insertion point on the SS lateral wall (p = 0.01), rather than a SS pneumatization (p = 0.63). The overall success was 95.5% after a mean follow-up of 35.9 months. For the literature, 26 publications were included on 97 patients and described a trans-sphenoidal approach with a success rate of 84.6% after a mean follow-up of 24.5 months.

CONCLUSION

IPSS is generally treated with a sphenoidotomy approach, although in selected cases, a TPA should be preferred to expose the whole SS lateral wall though allowing a complete pedicled oriented resection of the tumor.

Inverted Papilloma of the Middle Ear: Two New Cases and Systematic Review

INTRODUCTION

Inverted papillomas of the middle ear are extremely rare tumors that carry an increased risk of recurrence and malignant transformation. There are currently 59 cases of middle ear inverted papillomas reported in the literature. The objective in this study was to systematically evaluate outcomes regarding middle ear inverted papillomas with respect to demographics, anatomical tumor sites, malignant transformation status, recurrence rate and HPV status.

STUDY DESIGN

Retrospective case series and systematic review.

METHODS

A systematic review was completed on June 25, 2020 with a search strategy including PubMed, Embase, Scopus and Google Scholar. This revealed 181 articles. Full-text review was completed, and 66 articles were included. 115 articles were eliminated due to duplication of articles from databases, article titles not applicable to the aims of the systematic review and articles describing inverted papilloma of body sites other than middle ear.

DISCUSSION

Thirty-one cases of primary inverted papillomas of the middle ear were found in the literature with an additional 26 cases of secondary tumors. Four case reports did not specify primary versus secondary. The malignant transformation rate was 34.4% with a 53.6% recurrence rate. Treatment of middle ear inverted papillomas is primarily surgical with adjuvant radiation therapy considered for patients with recurrence or malignant transformation. Frequent clinical follow up of these patients is critical due to the increased rate of recurrence and malignant transformation.

CONCLUSION

Inverted papillomas of the middle ear are rare tumors that carry a high risk of recurrence and malignant transformation necessitating complete resection and frequent clinical follow up.

Long-term outcomes in sinonasal squamous cell carcinoma arising from inverted papilloma: Systematic review

Long-term survival and recurrence patterns of squamous cell carcinoma arising from inverted papilloma (IP-SCC) have not been thoroughly investigated. Four electronic databases were searched and primary studies describing overall survival (OS), recurrence, and mean time to recurrence of patients with IP-SCC were included for review. Our search yielded 662 studies. The 28 studies selected for inclusion identified 663 patients with IP-SCC. In 596 patients with reported T classification, 439 (73.7%) were T3/T4 on presentation. Of the 650 participants with recurrence data (local, regional, and distant), 155 (23.8%) experienced a recurrence, with an aggregate mean time-to-recurrence of 24.3 months. In 565 patients with 5-year OS rates, the aggregate 5-year OS was 62%. Based on the literature to date, IP-SCC is associated with a 5-year OS rate of 62%. 23.8% of patients experienced recurrence at a mean time of 24.3 months, suggesting the need for long-term surveillance.

A Systematic Review of Definitive Treatment for Inverted Papilloma Attachment Site and Associations With Recurrence

OBJECTIVE

Inverted papilloma (IP) is the most common benign neoplasm of the nasal cavity with known risk of recurrence. There is no standardized approach to definitive treatment for attachment sites. This systematic review aims to determine whether surgeon choice of technique differs by anatomic attachment site and whether different surgical techniques contribute to reduced rates of recurrence.

DATA SOURCES

PubMed and Ovid Medline.

REVIEW METHODS

A systematic review was conducted for studies reporting on IP. Those that included IP recurrence rates and primary tumor attachment site were reviewed.

RESULTS

Of 122 published studies, 14 met eligibility criteria, representing 585 patients and a recurrence rate of 5.8%. The maxillary sinus (50.9%) was the most common primary attachment site, and the sphenoid sinus was associated with the highest rate of recurrence (10.4%). The most utilized technique included debulking the tumor, removing mucosa over the attachment site, and drilling the underlying bone. The most common Krouse stage represented was T3 (53.3%). No single technique predicted a propensity for recurrence, but certain techniques are favored depending on IP attachment site. Finally, frozen sections to obtain evidence of clear margins intraoperatively significantly reduced rates of recurrence (3.4% vs 7.3%, P = .045).

CONCLUSION

Based on the current literature, the most common technique to address site of attachment involves resecting mucosa and drilling the tumor base. Choice of technique appears to differ for various sites of attachment. Use of intraoperative frozen section analysis appears to be associated with decreased recurrence overall.

LEVEL OF EVIDENCE

3.

Treatment strategies for inverted papillomas with intracranial or intraorbital involvement

OBJECTIVE

Sinonasal inverted papillomas are challenging benign tumours of the nasal cavity because of their high recurrence rates and the lifetime malignant transformation risk of 10 per cent as well as their locally aggressive behaviour. This study aimed to describe treatment strategies for inverted papillomas with intracranial or intraorbital involvement.

METHOD

This was a prospective case series study of 18 patients with inverted papilloma with intracranial or intraorbital involvement. Patient demographic data, imaging, pathology, surgical technique and recurrences were recorded prospectively over a period of seven years.

RESULTS

A total of 83 per cent of the patients in this study had been previously operated on, consisting of 8 cases with intracranial involvement, 1 case with intraorbital involvement and 9 with both. During follow up with a medium of 37 months (range, 13-115 months) there were two recurrences.

CONCLUSION

It was postulated that intracranial or intraorbital involvement observed in this series was the result of multiple revisions. However, using accurate imaging protocols and the pedicle-oriented approach for tumour excision, complete tumour removal was achieved in most cases with minimal post-operative complications.

Role of High-Risk HPV Detected by PCR in Malignant Sinonasal Inverted Papilloma: A Meta-Analysis

INTRODUCTION

Prior studies suggest that there may be a link between human papillomavirus (HPV) infection and malignant sinonasal inverted papilloma (SNIP). This systematic review and meta-analysis was performed to further evaluate this potential association.

STUDY DESIGN

Systematic review with meta-analysis.

METHODS

The Medline and Embase databases were used to identify case-control studies reporting the risk of malignant SNIP in patients with high-risk HPV subtypes identified by polymerase chain reaction (PCR). Meta-analysis was performed to determine pooled odds ratios (ORs) and 95% confidence intervals (CI).

RESULTS

Twenty-one studies were identified, including a total of 841 subjects with SNIP. Seventeen studies were included in the final analysis, as four studies did not have any HPV-positive tumors in either group. A total of 56 malignant SNIP and 551 benign SNIP were ultimately identified. The pooled log-OR was 1.80 (95% CI: 1.03-2.57) for all high-risk HPV subtypes. Stratification by high-risk HPV subtype showed a log-OR of 1.67 (95% CI: 0.88-2.46) for HPV-16 and log-OR of 2.68 (95% CI: 1.30-4.05) for HPV-18.

CONCLUSION

Infection with high-risk HPV subtypes may be associated with an increased risk of malignant SNIP. HPV-18 showed the greatest overall average effect size of the common high-risk subtypes.

LEVEL OF EVIDENCE

n/a Laryngoscope, 2021.

[Follow-up care of sinonasal papillomas - risk factors for recurrence and malignant progression]

OBJECTIVE

Sinonasal papillomas are tumors of the nasal cavity and paranasal sinuses. They are treated through complete resection under oncologic conditions. Two characteristics complicate follow-up: 1) frequent tumor recurrences (even many years after initial diagnosis), 2) possibility for malignant progression. This review elucidates risk factors for these two characteristics to depict "high-risk patients" for whom a closer follow-up is mandatory.

MATERIALS AND METHODS

Literature was searched in Pubmed (NCBI).

RESULTS

The most important risk factor for recurrence is incomplete tumor resection. This comprises several more factors: inappropriate surgical procedure, large tumors, difficult surgical conditions due to tumor localization or to prior surgery. Young age and tobacco smoking are risk factors for frequent recurrences. In regard to malignant progression, extended tumors, smoking, senior age, female sex, bone invasion, and lack of inflammatory polyps have been identified as risk factors. Histopathological factors for both - recurrences and malignant progression - are epithelial dysplasia, hyperkeratosis, squamous hyperplasia, as well as (if known) increased proliferation, aneuploidy, and infection with human papillomaviruses.

CONCLUSIONS

Complete resection of sinunasal papillomas under oncologic conditions is of utmost importance. A careful postoperative follow-up is mandatory. Most authors suggest at least a five-year, some a lifelong follow-up. Patients with one or more risk factors should be monitored more closely.

Need for long-term follow-up in sinonasal inverted papilloma: A Single-institution experience

BACKGROUND

Most studies on sinonasal inverted papillomas (SNIPs) regarding risk factors for recurrence, recurrence rates (RRs) and malignant transformation are biased by a significant proportion of revision cases.

METHODS

Retrospective study on patients with consecutive, treatment-naïve SNIPs at a tertiary referral center between 1999 and 2019.

RESULTS

Overall, RR was 9.8% (10 of 102 patients), with 2 of 10 recurrences (20%) occurring after more than 5 years. Histopathological workup revealed synchronous malignancy in 2 of 102 patients (2%). Subgroup analysis revealed a significantly higher RR for SNIPs involving the frontal sinus (26.3% vs 6.0%, P = .02). No SNIPs primarily originating from the frontal sinus were observed.

CONCLUSION

Overall, RR of treatment-naïve SNIPs is comparably low; however, long-term follow-up is mandatory due to late recurrences. Secondary involvement of the frontal sinus was identified as risk factor for recurrence. No SNIPs primarily originating from frontal sinus were observed.

Sinonasal inverted schneiderian papilloma presenting as a large intraoral lesion

Sinonasal inverted schneiderian papilloma (ISP) is a rare tumour, which almost exclusively arises from the mucosa lining, the nasal cavity and the paranasal sinuses. The tumour in its early stages presents as an asymptomatic mass, which may be discovered during routine examination. Large lesions usually measure a few millimetres to centimetres in size and show symptoms such as nasal blockade, recurrent sinusitis, postnasal drip, anosmia, epistaxis, facial pain and headache. Lesion presenting as a large oral mass is extremely rare and may cause diagnostic dilemma, resulting in misdiagnosis. This report describes a rare case of ISP presenting as large intraoral lesion, with wide area of facial skeletal involvement. Diagnosis and management of the pathology has also been highlighted.

Prognostic factors and risk factors for development and recurrence of sinonasal papillomas: potential role of different HPV subtypes

PURPOSE AND METHODS

A retrospective study was conducted to identify and assess potential clinical and molecularbiological risk factors for development and recurrence of sinonasal papillomas (i.e. inverted (IP), fungiform (FP), and oncocytic papillomas (OCP)). Investigated risk factors included age, gender, tumor size and localization, tobacco smoking, regular alcohol consumption, essential hypertension, anticoagulant medication, allergies, surgical approach, and HPV infection. Risk factors were evaluated by regression analysis.

RESULTS

Apart from age and incomplete tumor resection, the recurrence of Schneiderian papillomas is independent of conventional risk factors. Patients in this study displayed higher HPV infections rates in IP (38.8%) and in FP (100%) than in healthy mucosa, which is reported 0-5.8% in Germany and central Europe. The proportion of HPV-positive IP decreased with advanced tumor stages: 100% HPV positivity of T1 IP (2/2), 40.9% of T2 IP (9/22), and 35.7% of T3 IP (20/56). Most commonly detected HPV types were HPV 6, 11, and 16; however, patients in this study also displayed HPV types that have rarely or not at all been described in sinonasal papillomas before, such as HPV 58, 42, 83, and 91. Recurrent sinonasal papillomas displayed higher rates of HPV infections than non-recurrent tumors.

CONCLUSIONS

Young age at initial diagnosis and incomplete tumor resection are risk factors for recurrence of sinonasal papillomas. Our data suggest that HPV infection supports development and/or perpetuation of sinonasal papillomas. Additionally, sinonasal papillomas seem to display a unique subset of HPV genotypes, including genotypes that have not often been described before.

Inverted papilloma with multifocal attachment is associated with increased recurrence

BACKGROUND

Inverted papilloma (IP) is a benign sinonasal tumor with a well-known propensity to recur, especially at its bony attachment site. Anecdotal evidence suggests lower rate of recurrence in primary resection. We also aimed to evaluate the effect of multifocal vs single focus of attachment in disease control.

METHODS

This work is a retrospective review of 535 IP resections performed during the period from 2006 to 2016 at a tertiary-care center. Demographic data, tumor location and attachment sites, and follow-up duration data were obtained.

RESULTS

Two hundred ten patients were eligible for analysis. The mean age was 57 years, with an average postoperative surveillance of 36.4 months. Patients who had a previous procedure at an outside institution have a recurrence rate of 22.3%, compared with 12.4% for patients who had primary surgery at our institution. The most common site of attachment was maxillary sinus (47.6%), followed by ethmoid sinus (39%). Individual tumor review showed 50% of the patients to have multifocal attachment disease, of which there is a higher prevalence in secondary cases when compared with primary cases (53.7% vs 44.9%). Multiple tumor attachment sites had a significant effect on recurrence (odds ratio, 3.5; 95% confidence interval, 1.6-7.6; p = 0.002).

CONCLUSION

Primary resection and single-focus attachment of inverted papilloma are associated with lower recurrence rates at 3-year follow-up.

Morphologic, intraoperative, and histologic risk factors for sinonasal inverted papilloma recurrence

OBJECTIVE

Sinonasal inverted papillomas (IP) are benign neoplasms with a propensity for local recurrence. Many risk factors are reported, with little consistency between studies. This study aimed to comprehensively assess for demographic, imaging, histopathologic, and intraoperative risk factors for recurrence.

METHODS

We performed a single-center retrospective cohort study of patients with pathologically diagnosed IP without malignancy who underwent surgical resection between 1997 and 2018. Eligible patients were identified through a database maintained by the Department of Pathology. Logistic regression identified variables associated with recurrence, and conjunctive consolidation was performed to create a predictive model.

RESULTS

Of 76 subjects, 37% (n = 28) had recurrence. Median follow-up and time to recurrence were 2.9 (range 0.5-21.1) and 1.7 (range 0.2-13.0) years, respectively. Confirmed negative margins on histology were protective (odds ratio [OR] 0.25, 95% confidence interval [CI] 0.08-0.85). Frontal sinus involvement (adjusted odds ratio [aOR] 5.83, 95% CI 1.20-28.37), incomplete resection (aOR 9.67, 95% CI 2.24-41.72), and presence of dysplasia (aOR 4.38, 95% CI 1.01-19.10) were significantly associated with recurrence on multivariable analysis. A three-level composite recurrence risk staging system was created by consolidating the above three variables. The recurrence risks of composite stage I, II, and III disease were 20%, 38%, and 100%, respectively. No demographic, imaging, staging, or surgical approach variables were associated with recurrence.

CONCLUSION

Frontal sinus involvement, incomplete resection, and dysplasia were significant risk factors for IP recurrence, whereas confirmed negative margins were protective. Creation of a composite staging system using the above variables may allow for risk stratification and a patient-specific approach to postoperative IP management.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:590-596, 2020.

Surgical outcomes of sinonasal inverted papilloma: a 17 year review

Introduction

Inverted papillomas represent one of the most common benign neoplasic lesions located in the sinonasal tract. Owing to the local erosive behavior, tendency to recur and the potential for malignant transformation, surgical management of inverted papillomas is often challenging.

Objective

This study aimed to analyze the surgical outcomes of patients with inverted papillomas, according to the Krouse staging and the different surgical approaches.

Methods

Retrospective study of patients diagnosed with sinonasal inverted papillomas who underwent surgical treatment between 2000 and 2016 at a tertiary referral hospital. Cases with follow-up less than 12 months were excluded. The rate and the time of recurrence were the main outcomes. Values of p < 0.05 were considered statistically significant.

Results

Thirty-six cases with mean age of 60 years, predominantly male (72%), were included. The follow-up period ranged from 1 to 16 years, with an average of 4.5 years. Krouse T1 Stage corresponded to 11.1%; T2 occurred in 50% of cases; while T3 and T4 Stages accounted for 30.6% and 8.3% of patients, respectively. Most cases were approached by an endoscopic technique alone (83.3%), with a recurrence rate of 13.3%. Patients treated via a combined or open approach revealed a recurrence of 16.7%. No differences in the recurrence rate were reported when comparing endoscopic surgery with the open or combined techniques. Krouse Stage T3 had a significant association with inverted papillomas recurrence (p = 0.023). All inverted papilloma relapses occurred up to 2 years post-operatively. One case of malignant transformation was recorded (2.7%).

Conclusion

Endoscopic surgery did not increase the recurrence rates and can be a safe and efficient alternative to open or combined techniques. The recurrence of inverted papillomas seem to be related to the persistence of the disease and tend to occur early after primary surgery. Krouse T3 Stages may be associated with a higher recurrence of inverted papillomas.

Origin site-based staging system of sinonasal inverted papilloma for application to endoscopic sinus surgery

Background

We aimed to assess the recurrence risk of sinonasal inverted papillomas (SNIPs), based on a staging system developed according to the originating site of SNIP.

Methods

A total of 200 patients with SNIP were enrolled, and a staging system was developed based on the originating sites and corresponding recurrence rates of tumor in the patients. In the verification phase, 675 patients with SNIPs were enrolled as above, and the originating sites of the SNIPs were confirmed by an endoscopic sinus surgery. Cluster analysis was performed to determine the stage for each SNIP.

Results

Overall, 608 patients completed the study. SNIP recurrence rates for stages 1‐4 were 0 (n = 43), 4.0% (n = 420), 13.4% (n = 134), 36.4% (n = 11), respectively (total = 6.4%).

Conclusions

The origin site‐based classification of SNIP may aid surgeons in selecting appropriate endoscopic surgical approaches to minimize the risk of recurrence.

Imaging sphenoid diseases

In this review we provide comprehensive analysis of the imaging features of diseases affecting the sphenoid sinus, including a large and heterogeneous spectrum of pathologies such as sinusitis, pseudotumours, bony pathologies, and tumours. Clinical symptomatology related to sphenoid pathologies is often non-specific and patient clinical examination and endoscopic investigations are not definitive; thus, radiological imaging is mandatory for diagnosis. Strengths and limitations of both morphological and functional imaging methods such as computed tomography (CT), magnetic resonance imaging (MRI), and combined positron-emission tomography/computed tomography (PET/CT) have been considered and integrated into a well-defined clinical context in order to recognise specific imaging features and to underline their clinical relevance for an early and accurate diagnosis. An overview of several sphenoid conditions is herein selected with a didactic objective including both common and less common diseases.

The clinical behavior of sinonasal inverted papilloma with cellular dysplasia: case series and review of the literature

The prognosis and recurrence rate of inverted papilloma (IP) with concomitant cellular dysplasia are not well-delineated. Demographic, clinical and imaging data of all patients who were surgically treated for sinonasal inverted papilloma (SNIP) in our center between 1996 and 2013 were reviewed. Data regarding the coexistence of dysplastic changes or malignancy within the resected tissues were also retrieved. After the exclusion of malignant cases and patients who were lost for follow-up, 92 patients were included in the study. Five patients had coexisting cellular dysplasia (4.7%), four of them had severe dysplasia and one had mild-to-moderate dysplasia. All four cases with severe dysplasia recurred, three were primarily treated endoscopically and one by external approach. Only the case with mild to moderate dysplasia which had been treated by subcranial approach did not recur. Patients with dysplasia had significantly higher recurrence rate than patients without dysplasia (80 vs. 14%, p = 0.019). This significant relation between histology and recurrence remained even after adjustment to tumor extent. The adjusted odd ratio of dysplasia (dysplasia vs. no dysplasia) is 9.7, p = 0.043. SNIP with dysplasia should be treated aggressively and followed closely. The histopathologic investigation of SNIP specimens should always note the presence of dysplasia and its severity. Further investigation on the clinical behavior of SNIP with dysplasia is needed. Multicenter studies are warranted due to the rarity of dysplastic SNIP.

Complete response of skull base inverted papilloma to chemotherapy: Case report

Background:

Inverted papilloma (IP) is the most common benign sinonasal neoplasm. Endoscopic techniques, improved understanding of pathophysiology, and novel surgical approaches have allowed rhinologists to treat IPs more effectively, with surgery being the mainstay of therapy. Frontal sinus IP poses a challenge for surgical therapy due to complex anatomy and potentially difficult surgical access.

Objectives:

We reported a unique case of a massive frontal sinus IP that presented with intracranial and orbital extension, with near resolution after chemotherapy.

Methods:

A retrospective case review of a patient with a frontal sinus IP treated at a tertiary academic medical center.

Results:

A 75-year-old male patient presented with nasal obstruction, purulent nasal discharge, and a growing left supraorbital mass. Endoscopy demonstrated a mass that filled both frontal and ethmoid sinuses, with orbital invasion. There also was substantial erosion of the posterior table, which measured 1.73 × 1.40 cm. A biopsy specimen demonstrated IP with carcinoma in situ. The patient was deemed unresectable on initial evaluation and, subsequently, underwent chemotherapy (carboplatin and paclitaxel). The tumor had a dramatic response to chemotherapy, and the patient elected for definitive surgery to remove any residual disease. During surgery, only a small focus of IP was found along the superior wall of the frontal sinus. No tumor was found elsewhere, including at the site of skull base erosion. The final pathology was IP without carcinoma in situ or dysplasia.

Conclusion:

This was the first reported case of chemotherapeutic “debulking” of IP, which facilitated surgical resection, despite substantial intracranial and orbital involvement. Although nearly all IPs can be treated surgically, rare cases, such as unresectable tumors, may benefit from systemic chemotherapy.

Advances in recurrence and malignant transformation of sinonasal inverted papillomas

Sinonasal inverted papilloma (SIP) is a benign tumor of the nasal cavity and sinus. SIP is characterized by aggressive malignant transformation and a high rate of recurrence. Inadequate removal of the tumor during surgery is one of the most significant contributors to SIP recurrence. A growing body of evidence suggests that molecular alteration in SIP, including human papilloma virus infections, single nucleotide polymorphisms of key genes, deregulation of signaling pathways and immunological changes, may lead to SIP occurrence and malignant transformation. However, the extent to which these molecular mechanisms contribute to SIP pathology and transformation remains unclear due to limited research. Further studies are warranted to elucidate the primary dependent factors that contribute to SIP etiology. The present article reviewed risk factors of progression and recurrence of SIP, including outdoor and industrial occupational exposure, smoking, septal deviation, SIP location, recurrent cases, stage of SIP-associated squamous cell carcinoma and choice of surgical method.

Atypical presentations of sinonasal inverted papilloma: Surgical management and influence on the recurrence rate

BACKGROUND

Sinonasal inverted papilloma (SNIP), classically, is a unilateral benign tumor of the nasal lateral wall. Numerous variations have been observed, depending on location, bilateral presentation, or association with nasal polyposis.

OBJECTIVE

The aim of this work was to describe atypical presentations of SNIPs with their management specificities and to assess their influence on the recurrence rate in a large case series.

METHODS

A retrospective single center study of 110 patients treated for SNIP. Atypical inverted papillomas were identified according to the following criteria: (1) unusual location (frontal, posterior, anterior), (2) bilateral involvement, and (3) association with nasal polyposis. Surgical management was detailed, and the influence of each atypical group on recurrence was assessed by using Kaplan-Meier survival curves and the log-rank test.

RESULTS

Distribution of atypical presentations was as follows: frontal sinus localization (10.9%); posterior localization, including sphenoid sinus (9%); nasal anterior localization (3.6%); bilateral involvement (3.6%); and nasal polyposis association (10%). The surgical approach was endoscopic (74.5%), external (5.5%), or combined endoscopic and external (20%). Except for nasal anterior localization, all the groups were associated with a higher recurrence rate, without reaching statistical significance.

CONCLUSION

Recurrence rates for these atypical presentations arise from their specific surgical challenges. The choice of the surgical technique is guided by tumor location and extension, and by the surgeon's experience; the main objective is a complete resection. The endoscopic endonasal approach is the most frequent procedure.

Etiology of sinonasal inverted papilloma: A narrative review

Objective

Sinonasal inverted papilloma (IP) is a benign and uncommon tumor of the nasal cavity and paranasal sinuses with a tendency for recurrence and even malignant transformation. Though the morphology and clinical behavior of this lesion has been well described, its etiology remains controversial.

Methods

Computerized searches were performed in PubMed, Scopus, and Google scholar through May 2015. In this review, etiologic factors including human papilloma virus (HPV), Epstein–Barr virus (EBV), cell cycle related proteins and angiogenic factors, occupational and environmental exposures, and chronic inflammation, will be discussed.

Results

Many studies indicate that HPV has been detected in a significant percentage of IP, while EBV has not been shown to be significantly associated. Certain cell cycle regulatory factors and angiogenic proteins contribute to the dysregulation of proliferation and apoptosis, and facilitate migration and tumor invasion. Occupational exposures, such as welding and organic solvents, have been implicated, and smoking seems more critical to recurrence and dysplasia rather than initial IP occurrence. Chronic inflammation may also have a causative relationship with inverted papilloma, but the mechanism is unclear.

Conclusions

Though etiology of sinonasal IP remains controversial, the studies reviewed here indicate a role for viral infection, cell cycle and angiogenic factors, environmental and occupational exposure, and chronic inflammation. Further study on etiologic factors is necessary for clinical guidance and therapeutic targets.

Incidence of IP and risk of malignant transformation in the Swedish population 1960-2010

The true incidence of inverted papilloma (IP) is not yet known. From hospital-based studies, its incidence has been estimated to approximately 0.5/100,000 person years. Earlier hospital case studies have shown that IP can undergo a malignant transformation in 1-53 %. The frequency of its malignant transformation on a population basis is unknown. To our knowledge, no standardised incidence ratio (SIR) has been reported for malignancies among IPs. This study aims to investigate these incidences on a population basis. Using the data from the Swedish Cancer Registry (SCR), we have identified patients with IP and patients with Squamous Cell Carcinoma (SCC) diagnosed between 1960 and 2010 in Sweden. Incidence of IP and incidence of SCC among patients with IP and SIR were analyzed. Eight hundred and fourteen patients with IP were identified. The incidence of IPs reported to the SCR increased from 1960 to 2010. In this cohort, SCC was overrepresented, as compared with the general population. The incidence of IP in the Swedish population seems to have increased.

Recurrence of sinonasal inverted papilloma following surgical approach: A meta-analysis

OBJECTIVES/HYPOTHESIS

Inverted papilloma (IP) is a rare benign tumor, which is found in the sinonasal area. It is characterized by recurrence, local destruction, and malignant change. Of these, recurrence is a challenging problem to many otolaryngologists. In this study, we evaluated recurrence based on the type of surgical approach using a meta-analysis.

STUDY DESIGN

MEDLINE, Embase, and Cochrane database.

METHODS

Relevant studies were identified by searching the following databases: MEDLINE, Embase, and Cochrane through February 2016. Random-effects models were used to estimate risk ratio (RR) and 95% confidence interval (CI). The Newcastle-Ottawa scale was used to assess the quality of cohort studies.

RESULTS

Our search yielded 14 retrospective cohort studies involving a total of 696 endoscopic approaches and 444 nonendoscopic approaches. The pooled RR for IP recurrence (endoscopic vs. external approach) was 0.56 [95% CI: 0.36-0.85, I² =48.3%]. A subgroup analysis was also performed.

CONCLUSIONS

Surgical management of IP via an endoscopic approach reduces the risk of recurrence compared to an external approach. Although further data are needed, early- stage IP requires endoscopic or endoscopic-assisted surgery to reduce the risk of tumor recurrence.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:52-58, 2017.

Management Strategies for Skull Base Inverted Papilloma

Objective

Inverted papilloma attached to the ventral skull base presents a surgical dilemma because surgical removal of the bony pedicle is critical to decrease risk of recurrence. The objective of this study is to evaluate the effectiveness of endoscopic management of skull base inverted papilloma.

Study Design

Case series with planned data collection.

Setting

Tertiary medical center.

Subjects

Patients with skull base inverted papilloma.

Methods

Over 7 years, 49 patients with skull base inverted papilloma were referred for surgical resection. Demographics, operative technique, pathology, complications, recurrence, and postoperative follow-up were evaluated.

Results

Average age at presentation was 57 years. Twenty-six patients (53%) had prior attempts at resection elsewhere, and 5 had squamous cell carcinoma (SCCA) arising in an inverted papilloma. Six patients (12%) suffered major complications, including skull base osteomyelitis in 2 previously irradiated patients, cerebrospinal fluid leak with pneumocephalus (n = 1), meningitis (n = 1), invasive fungal sinusitis (n = 1), and cerebrovascular accident (n = 1). The mean disease-free interval was 29 months (range, 10-78 months). One patient with SCCA recurred in the nasopharynx (overall 2% recurrence rate). He is disease-free 3 years following endoscopic nasopharyngectomy. Three patients with SCCA had endoscopic resection of the skull base, while 1 subject with inverted papilloma pedicled on the superior orbital roof had an osteoplastic flap in conjunction with a Draf III procedure. All others received endoscopic resection.

Conclusions

Removal of the bony pedicle resulted in excellent local control of skull base inverted papillomas. Our experience demonstrates that disease eradication with limited morbidity is attainable with this approach.