Sinonasal inverted papilloma: narrative review

The diagnostic value of image-enhanced endoscopy system in sinonasal inverted papilloma

PURPOSE

This study aimed to evaluate the diagnostic value of image-enhanced endoscopy (IEE) in detecting sinonasal inverted papilloma (SNIP).

METHODS

Overall, 86 patients with unilateral nasal papillary or lobulated neoplasms were included between July 2018 and June 2019. All patients underwent IEE examinations, and the diagnosis of all neoplasms was confirmed through postoperative pathology. Logistic regression analysis was conducted to screen for independent predictors of various types of vascular patterns of SNIP. Furthermore, a prognostic nomogram was constructed using the independent predictors screened by logistic regression analysis to evaluate its usefulness in distinguishing SNIP from nasal polyp (NP) and papillary mucosa folds (PMF).

RESULTS

In total, 86 consecutive cases were observed, including 37 with SNIP, 40 with NP, and 9 with PMF. Logistic regression analysis showed that spot, corkscrew, and multilayered vascular patterns were independent predictors of SNIP diagnosis. Furthermore, a nomogram comprising the three independent risk factors was constructed with scores of 5, 2, and 3. The area under the receiver operating characteristic curve for predicting SNIP was 0.954, 0.66, 0.71, and 0.76 for the nomogram model, spot vascular pattern, corkscrew vascular pattern, and multilayered vascular pattern, respectively.

CONCLUSION

The nomogram model based on spot, corkscrew, and multilayered vascular patterns in SNIP observed using IEE can be a useful diagnostic tool for predicting and distinguishing between NP and PMF.

Diagnostic accuracy of clinical visual assessment using endoscopic images for nasal cavity mass lesions

Objectives: Discrimination of nasal cavity lesions using nasal endoscopy is challenging because of the differences in clinical manifestations and treatment strategies. We aimed to investigate the diagnostic accuracy of clinical visual assessment (CVA) of nasal cavity masses using endoscopic images and determine whether there is a difference according to pathologic class and the examiners' experience. Methods: We collected pathologically confirmed endoscopic images of normal findings, nasal polyp (NP), benign tumor, and malignant tumor (each class contained 100 images) randomly selected. Eighteen otolaryngologists, including six junior residents, six senior residents, and six board-certified rhinologists classified the test set images into four classes of lesions by CVA. Diagnostic performance according to the pathologic class and the examiner's experience level was evaluated based on overall accuracy, F1-score, confusion matrix, and area under the receiver operating characteristic curve (AUC). Results: Diagnostic performance was significantly different according to the pathological class of nasal cavity mass lesions with the overall accuracy reported high in the order of normal, NP, benign tumor, and malignant tumor (0.926 ± 0.100; 0.819 ± 0.135; 0.580 ± 0.112; 0.478 ± 0.187, respectively), F1 score (0.937 ± 0.076; 0.730 ± 0.093; 0.549 ± 0.080; 0.554 ± 0.146, respectively) and AUC value (0.96 ± 0.06; 0.84 ± 0.07; 0.70 ± 0.05; 0.71 ± 0.08, respectively). The expert rhinologist group achieved higher overall accuracy than the resident group (0.756 ± 0.157 vs. 0.680 ± 0.239, p < .05). Conclusion: CVA for nasal cavity mass was highly dependent on the pathologic class and examiner's experience. The overall accuracy was reliably high for normal findings, but low in classifying benign and malignant tumors. Differential diagnosis of lesions solely based on nasal endoscopic evaluation is challenging. Therefore, clinicians should consider further clinical evaluation for suspicious cases.

[Inverted papilloma of the nose and paranasal sinuses : Diagnosis, treatment, and malignant transformation]

Inverted papilloma (IP) are benign tumors that show a locally aggressive behavior, a high rate of recurrence, and a potential for malignant transformation. Specific radiological signs such as hyperostosis at the origin of the IP and convoluted cerebriform patterns, as well as the typical endoscopic aspect, can lead to diagnosis and enable preoperative planning of surgical access and the extent of surgery. Endonasal endoscopic techniques are considered the gold standard and the introduction of extended surgical techniques such as the prelacrimal approach, frontal drillout, or orbital transposition facilitate complete subperiosteal resection with preservation of important physiological structures. There is a risk of synchronous and metachronous squamous cell carcinomas (IP-SCC). Research focuses on radiological criteria to differentiate benign IP from IP-SCC, genetic and epigenetic factors in the process of malignant transformation, and estimation of the risk of IP progressing to IP-SCC.

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.

Unique clinical and prognostic behavior of patients diagnosed with combined exophytic and inverted papilloma histologic subtype

Objectives

To evaluate the clinical and prognostic behaviors of sinonasal papillomas.

Methods

Patients diagnosed with sinonasal papilloma were reviewed between 2001 and 2016 at a tertiary rhinology practice. Using pathology-specific electronic medical record software, patients diagnosed with sinonasal papilloma were identified. Four subcategories of this lesion were identified: inverting (IP), exophytic (EP) oncocytic (OP) and inverting + exophytic (IP + EP) papillomas.

Results

A total of 107 patients were identified with unique sinonasal papilloma diagnoses. Of these, the majority were diagnosed with IP (87, 81.3%). The subpopulation of patients co-diagnosed with IP and EP (IP + EP) was unique with respect to clinical presentation and prognosis relative to both the IP and EP alone populations. IP + EP patients (5, 4.7%) were older with an average age of 75.25 years compared to 45 (EP) and 55.26 (IP), p < .0001. IP + EP patients more often presented with epistaxis (60%) compared to 33.3% (EP) and 4.6% (IP). Finally, all IP + EP patients had at least one recurrence of their disease, compared to 33.3% (EP) and 28.5% (IP).

Conclusions

Each histopathologic subtype of sinonasal papilloma has unique clinical characteristics and recurrence rates after surgical resection. The subpopulation of patients diagnosed with IP + EP tends to be older, more likely to present with epistaxis, and more likely to recur. Additional investigation and analysis of this subpopulation is warranted.

Level of Evidence

4.

The Clinical Characteristics in Children with Sinonasal Inverted Papilloma: A Case Report and Review of the Literature

Sinonasal inverted papilloma (SNIP) is one of the most common benign epithelial tumors but rarely occurs in children. The case of a 9-year-old Chinese boy, who presented with a left maxillofacial hump, nasal obstruction, and left nasal cavity and maxillary sinus masses under nasal endoscopy, is reported. The lesion was first diagnosed as a sinonasal tumor. However, to our surprise, the mass was determined to be an inverted papilloma after a detailed histological examination. We retrospectively reported the clinical data of this case and reviewed the relevant literatures on SNIP. This report aims to provide new insights into the clinical characteristics in children with SNIP and improve the understanding of this disease.

Sinonasal inverted papilloma - malignant transformation and non-sinonasal malignancies

OBJECTIVES

To assess malignant transformation rate, non-sinonasal malignancies, and factors contributing to recurrence in patients treated for sinonasal inverted papilloma (SNIP).

STUDY DESIGN

Retrospective study.

METHODS

We retrospectively reviewed medical records of all patients treated for SNIP (n = 296) between the years 1984-2014 at Helsinki University Hospital. Data from the Finnish Cancer Registry confirmed the number of those patients with sinonasal and non-sinonasal malignancies.

RESULTS

Only 2 of 296 (0.7%) patients primarily diagnosed with benign SNIP developed sinonasal cancer in a mean follow-up of 5.8 years. The most common non-sinonasal cancer sites were similar to those reported for the whole Finnish population. None of the patients presented with an HPV-associated non-sinonasal malignancy. The recurrence rate among patients who underwent attachment-oriented surgery was significantly lower compared to those operated on with other approaches (40.2% vs. 56.6%, p = 0.006). Dysplasia in SNIP was associated with a higher recurrence rate (p < 0.001).

CONCLUSIONS

Malignant transformation of SNIP was rare. Patients with SNIP were not prone to HPV-associated non-sinonasal malignancies. Endoscopic resection and attachment-oriented surgery have become predominant approaches in the treatment of SNIP; meanwhile, the total number of SNIP recurrences has decreased.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:506-511, 2023.

A Rare Case of Cervical Squamous Cell Carcinoma Concurrent with Sinonasal Inverted Papilloma: A Case Report

Introduction

Cervical cancer is the fourth most common malignancy in women worldwide, and sinonasal inverted papilloma (SIP) is a rare benign sinus tumor with characteristics including a destructive growth pattern, high recurrence rate, and common malignant transformation. Cervical squamous cell carcinoma (SCC) combined with SIP has not been reported thus far.

Case Presentation

A 55-year-old woman was diagnosed with cervical SCC in our center and treated with concurrent radiochemotherapy. During the follow-up period after the completion of cervical cancer treatment, the progression of cervical squamous cell carcinoma was first considered because the squamous cell carcinoma antigen (SCCA) levels remained high and slowly increased. However, SIP was found after a detailed investigation. The SCCA levels returned to normal after surgery. Two months after the surgery, because SCCA slowly increased again, it was found that the SIP recurred. After additional surgical treatment, the SCCA level returned to normal.

Discussion and Conclusion

First, SCCA is an important indicator for monitoring changes in cervical SCC. When the changes in SCCA levels are inconsistent with the prognosis of cervical SCC, we should be vigilant about considering the possibility of other diseases existing at other sites in the body, which might lead to the earlier detection and treatment of SIP. Second, We recommended that SCCA be used as a routine monitoring index for SIP. If available, SCCA1 and SCCA2 should be evaluated to provide a more detailed assessment. Finally, for a high recurrence rate of SIP, anti-HPV treatment might be considered to reduce the risk of recurrence.

Sinonasal Inverted Papilloma and Squamous Cell Carcinoma: Contemporary Management and Patient Outcomes

Simple Summary

Inverted papillomas are benign sinonasal tumors that can recur or become cancerous. The mainstay of treatment is surgical resection. We summarize the biology of inverted papillomas and review surgical outcomes in an effort to define the current treatment strategy.

Abstract

Inverted papillomas (IP) are the most common sinonasal tumor with a tendency for recurrence, potential attachment to the orbit and skull base, and risk of malignant degeneration into squamous cell carcinoma (SCC). While the overall rate of recurrence has decreased with the widespread adoption of high-definition endoscopic optics and advanced surgical tools, there remain challenges in managing tumors that are multiply recurrent or involve vital neurovascular structures. Here, we review the state-of-the-art diagnostic tools for IP and IP-degenerated SCC, contemporary surgical management, and propose a surveillance protocol.

Case Report: Oncocytic Schneiderian Papilloma Originating From the Sphenoid Sinus

A rare case of oncocytic Schneiderian papilloma originating from the sphenoid sinus characterised, for 3 years, by non-specific symptoms of severe headache, a block of nasal breathing, and deprecating sense of smell was presented by an elderly female patient. Sphenoid sinus functional endoscopic sinus surgery (FESS), with a one-block tumour excision, through an endonasal approach, with a histological study of removed tumour masses, were performed on the patient. Long observation in the post-operative period was necessary, considering the risk of recurrence and malignancy of oncocytic Schneiderian papilloma (OSP). Although the oncocytic papilloma of the sphenoid sinus is rare, non-specific symptoms make this pathology easily misdiagnosed. Thus, any isolated unilateral process in the paranasal sinuses with long-existing symptoms must be given careful attention due to the chance of this process being an inverted papilloma with malignization. CT scan indicating a unilateral opacification of paranasal sinuses with local calcifications is a typical manifestation, and endoscopic sphenoidotomy can be recommended as a treatment of choice.

Preoperative Prediction of Malignant Transformation of Sinonasal Inverted Papilloma Using MR Radiomics

Purpose

Accurate preoperative prediction of the malignant transformation of sinonasal inverted papilloma (IP) is essential for guiding biopsy, planning appropriate surgery and prognosis of patients. We aimed to investigate the value of MRI-based radiomics in discriminating IP from IP-transformed squamous cell carcinomas (IP-SCC).

Methods

A total of 236 patients with IP-SCC (n=92) or IP (n=144) were enrolled and divided into a training cohort and a testing cohort. Preoperative MR images including T1-weighted, T2-weighted, and contrast enhanced T1-weighted images were collected. Radiomic features were extracted from MR images and key features were merged into a radiomic model. A morphological features model was developed based on MR morphological features assessed by radiologists. A combined model combining radiomic features and morphological features was generated using multivariable logistic regression. For comparison, two head and neck radiologists were independently invited to distinguish IP-SCC from IP. The area under the receiver operating characteristics curve (AUC) was used to assess the performance of all models.

Results

A total of 3948 radiomic features were extracted from three MR sequences. After feature selection, we saved 15 key features for modeling. The AUC, sensitivity, specificity, and accuracy on the testing cohort of the combined model based on radiomic and morphological features were respectively 0.962, 0.828, 0.94, and 0.899. The diagnostic ability of the combined model outperformed the morphological features model and also outperformed the two head and neck radiologists.

Conclusions

A combined model based on MR radiomic and morphological features could serve as a potential tool to accurately predict IP-SCC, which might improve patient counseling and make more precise treatment planning.

Exome sequencing reveals candidate mutations implicated in sinonasal carcinoma and malignant transformation of sinonasal inverted papilloma

We explored somatic mutations in dysplastic sinonasal inverted papilloma (SNIP), SNIP with concomitant sinonasal squamous cell carcinoma (SNSCC), and SNSCC without preceding SNIP. Ten SNIP and SNSCC samples were analyzed with exome sequencing and tested for human papillomavirus. The identified mutations were compared to the most frequently mutated genes in head and neck squamous cell carcinoma (HNSCC) in the COSMIC database. Exome sequencing data were also analyzed for mutations not previously linked to SNSCC. Seven of the most commonly mutated genes in HNSCC and SNSCC in COSMIC harbored mutations in our data. In addition, we identified mutations in 23 genes that are likely to contribute to SNIP and SNSCC oncogenesis.

HPV-Positive Status Is an Independent Factor Associated With Sinonasal Inverted Papilloma Recurrence

OBJECTIVES

The present study aimed to evaluate human papillomavirus (HPV) occurrence in sinonasal inverted papilloma (SNIP), and to assess factors associated with HPV positivity and SNIP recurrence.

STUDY DESIGN

Prospective study.

METHODS

We prospectively collected clinical data and fresh tissue specimens from 90 consecutive patients treated for SNIP at Helsinki University Hospital, between 2015 and 2019. Fourteen patients with recurrent SNIP underwent repeated tumor sampling. All tissue specimens were analyzed for the presence of HPV. Factors associated with SNIP recurrence and HPV positivity were assessed.

RESULTS

Among 107 SNIP specimens, 14 (13.1%) were positive for low-risk HPV and 6 (5.6%) were positive for high-risk HPV. HPV positivity was associated with an increased risk of recurrence (P = .004). Smoking was significantly associated with HPV positivity in SNIP (P = .01), but a history of HPV-related diseases or patient sexual habits did not correlate with HPV positivity. The recurrence rate was lower among patients with SNIP that underwent an attachment-oriented resection, compared to patients treated without attachment-oriented resections (78.6% vs 25.8%, P < .001).

CONCLUSIONS

The risk of SNIP recurrence was highly associated with 1) HPV positivity and 2) surgery without an attachment-oriented resection. Oncogenic HPV was rare in SNIP.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Establishment and genetic characterization of cell lines derived from proliferating nasal polyps and sinonasal inverted papillomas

To better understand the pathogenesis of nasal polyps (NPs) and sinonasal inverted papillomas (SIPs), we aimed to establish cell lines from fresh tissues of NPs and SIPs and characterize them. Primary cell cultures were obtained from two NP tissues (NP2 and NP3) and one SIP tissue (IP4). All the cells were polygonal in shape, expressed cytokeratin 14, and had normal diploid chromosome status. HPV58 DNA was detected in NP3. To obtain immortal primary cells, NP2 and IP4 cells were transduced with a combination of mutant CDK4, cyclinD1 and TERT. These cells were thereafter named NP2/K4DT and IP4/K4DT, respectively. HPV58-positive NP3 cells were transduced with TERT alone, the resulting cells named NP3/T. Phenotypic and genotypic identity of original tissues and derived cells was investigated. All the cell cultures with transgenes were confirmed to be derived from their parental cells and primary tumor tissues by analysis of short tandem repeats (STR) and maintained in vitro growth, genetic profiles and gene expression characteristics of the primary cells. These virtually immortalized cells, as well as the primary cells, have potential as in vitro models for studying the pathogenesis of NPs and SIPs and for preclinical study to develop new therapeutic agents.

Feasibility of a deep learning-based algorithm for automated detection and classification of nasal polyps and inverted papillomas on nasal endoscopic images

BACKGROUND

Discrimination of nasal cavity mass lesions is a challenging work requiring extensive experience. A deep learning-based automated diagnostic system may help clinicians to classify nasal cavity mass lesions. We demonstrated the feasibility of a convolutional neural network (CNN)-based diagnosis system for automatic detection and classification of nasal polyps (NP) and inverted papillomas (IP).

METHODS

We developed a CNN-based algorithm using a transfer learning strategy and trained it on nasal endoscopic images. A total of 99 nasal endoscopic images with normal findings, 98 images with NP, and 100 images with IP were analyzed using the developed CNN. Six otolaryngologists participated in clinical visual assessment. Image-based classification performance was measured by calculating the accuracy and area under the receiver operating characteristic curve (AUC). The diagnostic performance was compared between the CNN and clinical visual assessment by human experts.

RESULTS

The algorithm achieved an overall accuracy of 0.742 ± 0.058 with the following class accuracies: normal, 0.81± 0.14; IP, 0.57 ± 0.07; and NP, 0.83 ± 0.21. The AUC values for normal, IP, and NP were 0.91 ± 0.06, 0.82 ± 0.09, and 0.84 ± 0.06, respectively. The overall accuracy of the CNN model was comparable with the average performance of human experts (0.742 vs. 0.749; p = 0.11).

CONCLUSIONS

The trained CNN model appears to reliably classify NP and IP of the nasal cavity from nasal endoscopic images; it also yields a reliable reference for diagnosing nasal cavity mass lesions during nasal endoscopy. However, further studies with more test data are warranted to improve the diagnostic accuracy of our CNN model.

Clinical characteristics of sinonasal inverted papilloma associated with recurrence and malignant transformation

OBJECTIVE

Sinonasal inverted papilloma is a benign tumor but has a potential for recurrence and malignant transformation. The aim of this article is to analyze the clinical characteristics of sinonasal inverted papilloma associated with recurrence and malignant transformation.

MATERIAL AND METHODS

A retrospective study was performed in all patients with sinonasal inverted papilloma diagnosed between in our hospital during May 2013 and May 2018.

RESULTS

A total of 151 patients were enrolled in this study. The average age of these patients was 52.24 years, with a male-to-female ratio of 2.775:1, and the most frequent clinical symptom was nasal obstruction. The recurrence rate was 39.07% (59/151), the mean time of recurrence was 35.8 months and most recurrences occur within the first three years after surgery. There was no significant difference in recurrence rate between all four stages and between after endoscopic surgery and a combined endoscopic and external approach. The malignant transformation rate was 5.96% (9/151) and the mean time of malignant transformation was 9.06 months.

CONCLUSIONS

Because of its high recurrence rate and the potential of malignant transformation, so it is important to determine the primary site of the tumor and to make a complete removal and a follow-up of at least five years after surgery is recommended.

Bilateral Sinonasal Inverted Papilloma: Report of an Uncommon Case Involving Sinuses of the Face and Orbital Cavity

Patient: Male, 60-year-old

Final Diagnosis: Sinonasal inverted papilloma

Symptoms: Facial asymmetry • nasal obstruction • right hemiface proptosis

Medication: —

Clinical Procedure: —

Specialty: Dentistry • Pathology • Surgery

Rare Diseases of the Nose, the Paranasal Sinuses, and the Anterior Skull Base

Due to their low incidence and thus resulting limited diagnostic criteria as well as therapeutic options, rare diseases of the nose, the paranasal sinuses, and the anterior skull base are a significant challenge. The value as of which a disease has to be considered as rare amounts to a maximum of 5 patients per 10 000 people. Within these diseases, however, there are extreme differences. Some rare or orphan diseases like for example the inverted papilloma belong to regularly diagnosed and treated diseases of larger departments of oto-rhino-laryngology whereas other rare diseases and malformations have only been described in less than 100 case reports worldwide. This fact emphasizes the necessity of bundling the available experience of diagnostics and therapy. The present article gives an overview about rare diseases of the nose, the paranasal sinuses, and the anterior skull base from the field of diseases/syndromes of the olfactory system, malformations of the nose and paranasal sinuses, ventilation and functional disorders as well as benign and malignant tumors. The classification and data on diagnostic and therapeutic options were established based on the current literature.

Concurrent Inverted Papilloma and Squamous Cell Carcinoma with Intradural Extension Presenting with Frontal Lobe Syndrome

Inverted papilloma is an uncommon tumor mostly arising from the lateral wall of the nasal cavity and displays a benign but locally aggressive behavior. Intracranial extension is an extremely rare presentation of inverted papilloma. Extension occurs either as a benign lesion or due to malignant transformation. We report a case of concurrent inverted papilloma and squamous cell carcinoma presenting with epistaxis and recent-onset altered behavior and memory impairment. After literature review of similar cases having inverted papilloma with intracranial extension, we could identify a total of 12 cases, most of which were recurrences of a primary inverted papilloma that were resected before extension into the cranial cavity. Most cases were of extradural extension, and intradural spread resulted in poor prognosis on follow-up. Concurrent inverted papilloma and squamous cell carcinoma extending into the anterior cranial fossa and frontal lobe is a very rare clinical entity and can present as frontal lobe syndrome.

The role of Narrow Band Imaging (NBI) in the diagnosis of sinonasal diseases

BACKGROUND

Narrow band imaging (NBI) endoscopy is an optical method that helps to characterise tissue vasculature. Its appli- cation in sinonasal pathology remains scarce and a systematic study of its application to rhinology is lacking. The aim of this study is to analyse and describe the normal sinonasal mucosa under NBI light and to characterise the microvascular features of various sinonasal pathologies. We also want to suggest a classification of the patterns, peculiar to this district, and to evaluate whether they can be indicative of a specific physiological or pathological condition.

METHODS

Digital videos and images under white light and NBI of 103 patients (82 evaluated) with 29 sinonasal pathologies and 55 controls (33 evaluated). were independently analysed by three otolaryngologists and the final pattern was then arranged for each image, reaching an agreement between the individual evaluations.

RESULTS

Once the appearance of normal sinonasal (SN) mucosa was established (SN1), four patterns for the pathological mucosa were described and a working classification was proposed (SN2, SN3, SN4, SN5). We calculated specificity (80.6% vs 90.6%), sensi- tivity (20% vs 38.5%), PPV (46.1% vs 50%), NPV (54.7% vs 85.7%) and accuracy (53% vs 80.3%) of the ability of SN4 and SN5 pattern to discriminate between benign and malignant nasal neoformations.

CONCLUSIONS

This is the first study to propose a systematic NBI description and a classification of the vasculature of healthy and pathological mucosa in the sinonasal tract. Our preliminary results show that this technique can help in the workup of several rhinologic conditions and especially in distinguishing benign from malignant tumors.

Temporal bone primary inverted papilloma - Case Report and review of the literature

Inverted papilloma of middle ear is an extremely rare lesion of the respiratory epithelium that normally occurs in the nasal cavity and paranasal sinuses. So far less than 17 cases were described in literature. A 45-year-old patient was admitted in our Department with hearing loss, otorrhea and pulsing tinnitus on the right ear. The clinical examination showed a granulation tissue on the right eardrum. No tumor formation was seen in the nasal cavity. The MRI showed a tissue formation in the tympanic cavity with an extension in the middle cranial fossa. A mastoidectomy with antrotomy and duraplasty was performed. The histological diagnosis was inverted papilloma of the middle ear. In a second step occurred an eradication of the tumor with a subtotal petrosectomy. The etiology of the inverted papilloma of the middle ear is unknown. Our case is so far the 18^nd case described.Our experience has shown that the eradication of the tumor with a subtotal petrosectomy resulted as reasonable procedure. A long-term follow-up is suggested in order to detect possible recurrence or malignant transformation.

Imaging of sino-nasal inverted papilloma: How can we emphasize the usefulness of the “striated pattern” sign?

Background

Inverted papilloma (IP) is an uncommon sino-nasal neoplasm with potentially distinctive MRI and CT features. The MR “striated” imaging pattern has been reported as a valuable MR imaging feature of IP. The purpose of this study was to validate the usefulness of this sign using detailed criteria of the sign itself.

Results

All imaging findings were described for 16 patients in descriptive pattern. The nasal involvement showed highest prevalence followed by the maxillary sinus. The bony changes include remodeling and defects (n = 6), remodeling only (n = 4), and None (n = 6). Changes were severe 1/10, moderate in 3/10, and mild 5/10. Focal hyperostosis was seen in six. A striated pattern was “diffuse” in all 16 (100%) of the IPs; it followed a certain direction in all 16 patients: divergent (n = 6), convoluted (n = 2), and parallel (n = 8). Divergent growth from focal hyperostosis was seen (n = 4). Visibility of the sign was superior in T2 images (n = 11), superior in enhanced images (n = 3), and equal in both (n = 2).

Conclusions

The striated pattern is a reliable MR imaging feature of sino-nasal IPs. Validity and usefulness of this sign can be emphasized by defining parameters of the signs itself including the following: diffusivity, direction of striations and relation to hyperostosis, and comparing visibility in both T2 and GAD-enhanced images, as well as combining this imaging signature with remolding bony changes < 1.5.

[Unilateral diseases of the maxillary sinus]

Unilateral diseases of the maxillary sinus are among the most common rhinologic diagnoses. The diversity of these diseases can represent a challenge for the treating physician. The spectrum ranges from harmless maxillary sinus cysts that seldom require treatment, to highly aggressive malignant tumors. Special attention should be given to the management of inverted papilloma. These benign tumors are characterized by high recurrence rates and the potential for malignant transformation. The key to minimizing recurrence is precise surgical intervention. Other unilateral maxillary sinus diseases such as the antrochoanal polyp and the fungus ball (aspergilloma) are also discussed in depth.

A clinical analysis of sinonasal squamous cell carcinoma: a comparison of de novo squamous cell carcinoma and squamous cell carcinoma arising from inverted papilloma

Background: Sinonasal squamous cell carcinoma (SCC) is a rare tumor arising either de novo or in association with inverted papillomas (IPs).Objectives: The aim of this study was to investigate and compare the oncological features and prognosis of patients with sinonasal SCCs based on their etiology.Material and methods: The medical records of 117 patients who had been diagnosed with de novo SCC or those arising from IP (IP-SCC) were retrospectively reviewed. In situ hybridization analyses to detect HPV 16/18DNA and p16 immunohistochemistry were also performed in 10 cases with IP-SCC.Results: The three-year disease-specific survival (DSS) rate was higher in cases with T1, 2 and 3 than in cases with T4 in both tumor groups. T4 cases with de novo SCC had a better DSS than those with IP-SCCs. HPV16/18 was not detected in any of the 10 IP-SCCs.Conclusions and significance: T4 cases with de novo SCC tended to have a better DSS than those with IP-SCC. Since some T4 patients with IP-SCC were found to have a highly aggressive disease, careful treatment planning should be performed. High-risk HPV may not play a vital role in the carcinomatous transformation of most IP-SCC cases.

Prognostic Factors of Sinonasal Squamous Cell Carcinomas Arising De Novo and From Inverted Papilloma

BACKGROUND

The prognostic factors and survival difference between inverted papilloma (IP)-associated sinonasal squamous cell carcinoma (SCC) and de novo SCC are unclear.

OBJECTIVE

This study aimed to compare the clinical features and oncologic outcomes in patients with IP-associated SCC and de novo SCC; and additionally, to analyze the prognostic factors of the two types of SCCs.

METHODS

Data from 173 SCC patients treated for IP-associated SCC (n = 89) and de novo SCC (n = 84), were reviewed retrospectively for demographic features, tumor characteristics, treatment modality, and clinical outcomes. 5-year overall survival (OS) and disease free survival (DFS) was analyzed using the Kaplan-Meier method, and Cox proportional hazards model was used to analyze factors influencing prognosis.

RESULTS

A higher proportion of IP-associated SCC occurred in frontal and sphenoid sinus compared to de novo SCC. The two groups demonstrated similar 5-year OS and DFS (5-year OS: 63.3% and 55.4%, DFS: 45.4% and 50.1%, respectively). The metachronous tumor had a relatively better prognosis outcome than synchronous tumor and de novo SCC (5-year OS: 73.1%, 54.5% and 55.4%, respectively). Both groups showed similar loco-regional recurrence rates (p > 0.05); however, de novo SCC tumors demonstrated an increased incidence of distant metastasis. Multivariate analysis indicated that age >70 years, advanced tumor stage and surgical margin were independent predictive factors for the risk of mortality (HR 2.047, 1.581 and 1.931, respectively).

CONCLUSION

IP-associated SCCs have an aggressive loco-regional tendency, whereas de novo SCCs have a higher aggressive distant metastatic propensity. Age, tumor stage and surgical positive margin are key factors for poor prognosis and should be routinely taken into consideration during treatment planning and subsequent surveillance.

Prevalence and association of Epstein-Barr virus infection with sinonasal inverted papilloma and sinonasal squamous cell carcinoma in the northeastern Thai population

Aims

Sinonasal inverted papillomas (SIP) and sinonasal squamous cell carcinomas (SNSCC) are sinonasal tumors with unclear etiology and pathogenesis. Epstein-Barr virus (EBV) has been detected in these tumors but information concerning their association is still limited. This study aimed to investigate the prevalence in, and association of EBV infection with SIP and SNSCC in northeastern Thailand.

Methods

DNA was extracted from 226 formalin-fixed, paraffin-embedded tissues including 80 nasal polyps (NP; the control group), 64 SIP and 82 SNSCC samples. Presence of EBV in these tissues was investigated using real-time PCR and their localization within tissues was confirmed using in situ hybridization (ISH). Characteristics of patients and the association of EBV prevalence with sinonasal tumors were analyzed.

Results

SIP and SNSCC were frequently found in people aged > 50 years and more often in males than in females (3:1 ratio). EBV infection was detected in 33.75, 64.06 and 37.80% of NP, SIP and SNSCC tissues, respectively, by real-time PCR. There was a statistically significant association between EBV infection and SIP (odds ratio [OR] = 3.52). This was not the case for SNSCC when compared to the NP group (OR = 1.83). Interestingly, EBV infection tended to be associated with inflammation and dysplasia in SIP. In SNSCC, EBV was mostly found in samples with undifferentiated or poorly differentiated cell types as well as in recurrent cases and lymph-node metastasis. Using ISH, EBV was detected only in infiltrating lymphocytes within the tumor stroma, not in the tumor epithelial cells.

Conclusions

Infiltrating lymphocytes containing EBV in the tumor microenvironment might enhance tumorigenesis of SIP and SNSCC. The mechanism by which EBV promotes development of SIP and SNSCC needs to be elucidated in the future.

A multimodal diagnostic approach to inverted papilloma: Proposal of a novel diagnostic flow-chart

PURPOSE

Inverted papilloma (IP) is a tumor usually arising from sinonasal cavities, with tendency for recurrence and possible malignant transformation. Along with endoscopy, computed tomography (CT) and magnetic resonance imaging (MRI) play a crucial role in defining preoperative staging, tumor origin, and possible differential diagnosis, with significant repercussions on therapeutic planning. However, at present no consensus has been reached concerning IP diagnostic workup. Aim of this study is to assess CT and MRI sensitivity and specificity in identifying IP imaging hallmarks, evaluating their global diagnostic accuracy in order to define a novel diagnostic flowchart.

METHODS

We retrospectively analyzed multimodal imaging of patients with histologically confirmed IP and mimics. Two neuroradiologists in consensus retrospectively rated the presence of typical imaging features of IP, both on CT and MRI scans. Sensitivity, specificity and diagnostic accuracy were assessed for both the techniques. Final results were expressed as ROC curves and relative areas under the curve (AUC).

RESULTS

The AUC considering CT parameters were 0.42, whereas the AUC considering MRI parameters were 0.54. Combining the 2 techniques and limiting the evaluation to the most distinctive features such as focal hyperostosis and CCP, the AUC was 0.79.

CONCLUSION

MRI can provide better tissue characterization and higher diagnostic accuracy in case of suspected IP, whereas CT is more useful in determining bony involvement. Here we propose a possible diagnostic flowchart for IP, based on the assumption that the combination of the imaging techniques allows to optimize the clinical assessment and the subsequent therapeutic planning.

Low Epstein-Barr virus count in sinonasal inverted papilloma

Background: Sinonasal inverted papilloma (SIP) is a benign tumour originating from the sinonasal mucosa showing an extensive growth pattern, a high risk of recurrence and a 5-10% risk to malignify. Epstein-Barr virus (EBV) is an oncogenic herpesvirus which infects most individuals via the saliva eliciting a latent infection. Previous studies have been reporting variable data on EBV in SIP, and there is no present appreciation regarding the association between these.Aims/objectives: The aims were to investigate the presence and count of EBV in SIP and map the viral distribution in the epithelium versus the connective tissue.Material and method: Fifty-three SIP patients were identified in the Pathology Department register at the University Hospital of Umeå. The biopsies were analysed with Epstein-Barr Encoded Region (EBER) in situ hybridization. EBER-positive cells were counted in the epithelium and connective tissue.Results: We found EBER-stained cells in 30% of the cases, where 19% of these had an abundance of stained cells, and the rest showed a low count.Conclusions/significance: These findings demonstrate a low EBV count in SIP. EBV is less likely to be a causative agent in the formation of SIP, or its malignant transformation.

Comparison of outcomes between patients with de-novo sinonasal squamous cell carcinoma vs malignant transformations from inverted papillomas

BACKGROUND

The survival difference between de-novo sinonasal squamous cell carcinoma (DN-SNSCC) and SCC arising from inverted papillomas (IPs) is unclear. The purpose of this study was to compare the outcomes between DN-SNSCC and IP-transformed SNSCC (IP-SNSCC) patients.

METHODS

In this retrospective review, we compared IP-SNSCC and DN-SNSCC cases from the Eye and ENT Hospital of Fudan University from 2010 to 2017. A total of 162 patients (39 IP-SNSCC and 123 DN-SNSCC) were included in our study. Demographics, tumor characteristics, treatment, and clinical outcomes were analyzed.

RESULTS

The median follow-up time in all cohorts was 56 (range, 5-109) months. There was no difference in age, sex, smoking history, alcohol consumption, tumor primary site, or disease stage between the IP-SNSCC and DN-SNSCC patients. We also did not find significant differences in overall survival and disease-free survival between IP-SNSCC and DN-SNSCC patients (p = 0.584 and p = 0.238, respectively). The 5-year local failure rate was 52.8% for IP-SNSCC patients, which was significantly higher than for those with DN-SNSCC (31.9%; p = 0.013). The 5-year nodal failure rate was 19.0% for IP-SNSCC patients and 8.5% for DN-SNSCC patients (p = 0.211). The 5-year distant metastasis rate was 8.0% for IP-SNSCC patients and 16.1% for DN-SNSCC patients (p = 0.318).

CONCLUSION

IP-SNSCC and DN-SNSCC patients have similar survival outcomes. IP-SNSCC seems to have exhibited a higher local failure rate in our study. We believe that IP-SNSCC is a highly aggressive disease that requires radical treatment. Prophylactic neck treatment should not be omitted in a subset of IP-SNSCC patients.

The serum squamous cell carcinoma antigen level in inverted sinonasal papilloma and nasal polyps patients

Objective

To clarify whether the serum squamous cell carcinoma antigen (SCCA) levels of patients with inverted papilloma (IP) are different from patients with nasal polyps (NP) and rhinitis.

Materials and methods

Serum SCCA levels were measured in 30 patients with IP and 30 patients with NP at one day before surgery and seven days after surgery and measured in 28 patients with rhinitis.

Results

Elevated serum SCCA levels (>1.5 ng/ml) were found in 80.0% of patients in the IP group, 6.7% of patients in the NP group and 14.3% of patients in the rhinitis group, which was a significant difference. The medians of serum SCCA levels in the IP, NP and rhinitis groups were 3.9, 0.8 and 1.1 ng/ml, respectively, which was a significant difference. The SCCA level in IP group was not significantly correlated according to Krouse Staging. There was a significant difference in serum SCCA levels between the pre- and postoperative stages in the IP group, at 3.9 and 0.8 ng/ml, respectively, while in the NP group the levels were 0.8 and 1.0 ng/ml, not significantly different. With regard to the IP diagnosis in the IP and NP group based on the SCCA level (>1.5 ng/ml), sensitivity and specificity was 80.0% and 93.3%, respectively.

Conclusions

The serum SCCA level in patients with IP was elevated and then it decreased after surgery. This was different from NP and rhinitis patients who mostly had normal levels, which did not change.

Surgery of Inverted Papilloma of the Maxillary Sinus via Translacrimal Approach-Long-Term Outcome and Literature Review

There are several differential diagnoses of unilateral sinus disease. One of these is inverted papilloma (IP) of the maxillary sinus, which is a common benign tumor with a substantial rate of malignant transformation. In general, endoscopic endonasal techniques for addressing the tumor are favored nowadays instead of classical external approaches. The aim of this retrospective study was to investigate the long-term outcome of inverted papilloma treated endoscopically via the prelacrimal approach. We reviewed 17 patients with primary or recurrent IP of the maxillary sinus that were treated via the prelacrimal endoscopic endonasal technique. After a median follow-up period of 45.9 months (3.8 years), none of the 17 included patients showed signs of recurrent disease and no serious complications were reported. Hypoesthesia of the incisors was reported by four patients and was resolved with time in one. All of the maxillary sinuses could be fully visualized with the flexible endoscope. IP is an important differential diagnosis in the clinical finding of unilateral nasal polypoid lesions. The prelacrimal approach is an effective and safe method in the treatment of IP with limited patient morbidity.

High CT attenuation values relative to the brainstem may predict squamous cell carcinoma arising from inverted papilloma

Background: A diagnostic indicator for differentiating squamous cell carcinomas (SCCs) from inverted papillomas (IPs) has not been established. Objectives: This study aimed to evaluate whether CT attenuation values relative to those of the brainstem (relative CT number) could be useful in differentiating IPs from SCCs. Material and Methods: Consecutive patients who were pathologically diagnosed with IP or SCC between 2007 and 2017 were retrospectively identified. Relative CT numbers were compared between the two patient groups. The factors with predictive power for differentiating IPs from SCCs were identified by univariate and multivariate logistic regression analyses. Results: Fifty-four sinonasal tumour cases were finally analysed (IP, 25 cases; SCC, 29 cases). Relative CT numbers were significantly higher in SCC than in IP (p < .001). The univariate logistic regression analysis showed BMI, relative CT number, and disease duration to have predictive value for differentiating IPs from SCCs. In the multivariate logistic regression analysis, only the relative CT number had predictive value for distinguishing IP from SCC (odds ratio, 1.97), with a relative CT number of ≥1.4 being significantly associated with SCC. Conclusions: High relative CT numbers could potentially be used to identify SCCs, and their measurement could provide a basis for differentiating IPs from SCCs.

Survival outcomes and prognostic factors of squamous cell carcinomas arising from sinonasal inverted papillomas: a retrospective analysis of 120 patients

BACKGROUND

This study aimed to analyze the prognostic factors and survival outcomes of squamous cell carcinoma (SCC) originating from sinonasal inverted papillomas (IPs), based on data from a single institution.

METHODS

The data from 120 patients treated at the affiliated Beijing Tongren Hospital, Capital Medical University, for SCC originating from sinonasal IPs between 2005 and 2018 were retrospectively reviewed. Data related to demographic features, tumor characteristics, treatment modality, and clinical outcomes were collected. Survival data were investigated using the Kaplan-Meier method, Cox regression analysis, and the nomogram model predictive of survival probabilities.

RESULTS

Among 1034 patients with sinonasal IPs, 120 patients (11.6%) with malignancy were identified. The overall survival (OS) and disease-free survival (DFS) rates at 5 years were 56.0% and 42.3%, respectively. Multivariate analysis showed that synchronous tumors and tumor stage were independent predictive factors for the risk of mortality (hazard ratio [HR], 1.954; 95% confidence interval [CI], 1.022-3.737, p = 0.043; HR, 1.737, 95% CI, 1.095-2.770, p = 0.020, respectively). The surgical margin was another important independent predictor, with patients with negative margins demonstrating a more than 2-fold improved survival compared to those with positive margins (HR, 2.095; 95% CI, 1.031-4.243; p = 0.041).

CONCLUSION

The main factors affecting the prognosis and outcomes were synchronous tumors, advanced tumor stage, and positive surgical margins. These findings highlight the importance of tumor biology and early detection in patient outcomes. In addition, risk factors should be taken into consideration during treatment planning and subsequent tumor surveillance.

Comparative transcriptome analysis of sinonasal inverted papilloma and associated squamous cell carcinoma: Out-HOXing developmental genes

BACKGROUND

Sinonasal papilloma has a tendency toward local destruction, recurrence, and malignant transformation. This study aimed to unravel mechanisms in the malignant transformation of sinonasal papillomas using RNA-seq.

METHODS

The cohort consisted of 37 consecutive patients; tumor histology included a continuum spectrum (sinonasal papillomas/dysplastic/carcinomas-in-situ/invasive squamous cell carcinomas). These were microdissected and RNA was subjected to whole-transcriptome shotgun sequencing.

RESULTS

RNA-seq and pathway analysis showed that the highest expressed genes/potential drivers were development- and differentiation-related genes. The protein expression of six highly upregulated genes (HOXA9, EN1, DUX4, CA9, CD1a, and CK5/6) validated the RNA-seq results. HOXA9 and CA9 were found to be expressed in most of the carcinoma samples but were largely negative in papillomas; all of the CA9-negative carcinomas were recurrent.

CONCLUSIONS

We conclude that sinonasal carcinomas arising from papillomas are mainly defined by overexpressed developmental/homeobox genes, which provide the potential for transformation/plasticity, along with differentiation and proliferation behavior of neoplastic cells. Our results support HOXA9 and CA9 as biomarkers for carcinomas, with CA9 emerging as a predictive marker of recurrence.

Optical imaging with a high-resolution microendoscope to identify sinonasal pathology

OBJECTIVES

High-resolution microendoscopy (HRME) is an optical imaging modality that allows real time imaging of epithelial tissue and structural changes within. We hypothesize that HRME, using proflavine, a contrast agent that preferentially stains cell nuclei and allows detection of cellular morphologic changes, can distinguish sinonasal pathology from uninvolved mucosa, potentially enabling real-time surgical margin differentiation.

STUDY DESIGN

Ex vivo imaging of histopathologically confirmed samples of sinonasal pathology and uninvolved, normal sinus epithelium.

SETTING

Single tertiary-level institution.

SUBJECTS AND METHODS

Five inverted papillomas, one oncocytic papilloma, two uninvolved sinus epithelia specimens, and three inflammatory polyps were imaged ex vivo with HRME after surface staining with proflavine. Following imaging, the specimens were submitted for hematoxylin and eosin staining to allow histopathological correlation.

RESULTS

Results show that sinonasal pathology and normal sinus epithelia have distinct HRME imaging characteristics. Schneiderian papilloma specimens show increased nuclear-to-cytoplasmic ratio, nuclear crowding, and small internuclear separation, whereas normal sinus epithelia specimens show small, bright nuclei with dark cytoplasm and relatively large internuclear separation. Inflammatory polyps, however, have varying imaging characteristics, that resemble both Schneiderian papilloma and normal sinus epithelia.

CONCLUSIONS

This study demonstrates the feasibility of HRME imaging to discriminate sinonasal pathology from normal sinus epithelia. While the system performed well in the absence of inflammation, discrimination of inflamed tissue was inconsistent, creating a significant limitation for this application. Novel imaging systems such as HRME with alternative contrast agents may assist with real-time surgical margin differentiation, enabling complete surgical resection of inverted papilloma and reducing recurrence rates.

Multifocal sinonasal inverted papilloma with middle ear involvement

Inverted papilloma of the nasal cavity is a benign neoplasm, although it can be locally invasive and has the potential for malignant degeneration. Inverted papilloma of the temporal bone is extremely rare. We describe a case of a 44-year-old woman who was treated for nasal inverted papilloma and was later found to have inverted papilloma of her temporal bone. The patient required several procedures to remove the inverted papilloma from the nasal cavity and temporal bone, and she is currently free of recurrence.

Low-Grade Papillary Schneiderian Carcinoma: A Case Report

The nasal cavity and paranasal sinuses are covered with ciliated respiratory mucosa of ectodermal origin, known as Schneiderian epithelium, which can give rise to different types of sinonasal carcinomas. A 42-year-old woman with a history of nasal polypectomy 3 years previously presented with nasal obstruction and rhinorrhea. She was found to have a papillary mass involving the left nasal cavity, and the left maxillary and ethmoidal sinuses by radiologic examination. She underwent endonasal resection under the diagnosis of oncocytic papilloma. The resected specimen showed exuberant invasive growth of papillary or inverted architectures of epithelial cells. The neoplastic cells were very bland, showing a round to polygonal shape, low nuclear-to-cytoplasmic ratio, abundant oncocytic cytoplasm, uniform nuclei, indistinct nucleoli, and scarce mitosis. The overall features were identical to those of a recent report of a low-grade papillary Schneiderian carcinoma. The main differential diagnosis is Schneiderian papilloma, and awareness of this novel entity is important for its proper treatment.

Malignant transformation of sinonasal inverted papilloma and related genetic alterations: a systematic review

Schneiderian papillomas are uncommon tumors which may develop within the nasal cavity and comprise three well-defined histological types: sinonasal inverted papilloma (SNIP), exophytic papilloma, and oncocytic papilloma. It is well known the rate of Schneiderian papilloma may also present a malignant degeneration and SNIP represents the most important subgroup in consideration of its frequency and malignant propensity. Although HPV infection is always considered the first event favoring the development of SNIP, however, it is not established as an eventual connection between viral actions and malignant transformation. In fact, different molecular mechanisms are suspected to play a crucial role in this process and, currently, many authors agree that only by improving our knowledge about these mechanisms it will be possible to achieve new and effective targeted therapies. So the aim of this study was firstly to systematically review the literature focusing on different biomarkers that could be implicated in the stages of SNIP malignant degeneration. Secondly, a systematic review with meta-analysis was performed to better define the incidence of sinonasal malignancies originating from Schneiderian papilloma (SNIP, exophytic papilloma, and oncocytic papilloma). Twenty-nine studies comprising a total of 3177 patients were statistically analyzed. Results showed a 9% (95% CI = 7-11) overall rate of malignant transformation from Schneiderian papilloma. In conclusion, this analysis confirmed that the potential malignancy of Schneiderian papilloma should not be underestimated. On the other hand, our review showed the paucity of studies investigating the molecular alterations which may be related with the malignant transformation of SNIP.

OSPs and ESPs and ISPs, Oh My! An Update on Sinonasal (Schneiderian) Papillomas

Sinonasal (Schneiderian) papillomas are benign neoplasms that arise in the sinonasal tract. Since their initial descriptions, sinonasal papillomas have triggered debate regarding their classification, etiology, rate or predictors of malignant transformation, and other issues. While significant strides have been made in recent years, there are still aspects of sinonasal papillomas that remain unclear even now. This review will serve to update the practicing pathologist on the current understanding of sinonasal papillomas.

MRI-Based Texture Analysis to Differentiate Sinonasal Squamous Cell Carcinoma from Inverted Papilloma

BACKGROUND AND PURPOSE

Because sinonasal inverted papilloma can harbor squamous cell carcinoma, differentiating these tumors is relevant. The objectives of this study were to determine whether MR imaging-based texture analysis can accurately classify cases of noncoexistent squamous cell carcinoma and inverted papilloma and to compare this classification performance with neuroradiologists' review.

MATERIALS AND METHODS

Adult patients who had inverted papilloma or squamous cell carcinoma resected were eligible (coexistent inverted papilloma and squamous cell carcinoma were excluded). Inclusion required tumor size of >1.5 cm and preoperative MR imaging with axial T1, axial T2, and axial T1 postcontrast sequences. Five well-established texture analysis algorithms were applied to an ROI from the largest tumor cross-section. For a training dataset, machine-learning algorithms were used to identify the most accurate model, and performance was also evaluated in a validation dataset. On the basis of 3 separate blinded reviews of the ROI, isolated tumor, and entire images, 2 neuroradiologists predicted tumor type in consensus.

RESULTS

The inverted papilloma (n = 24) and squamous cell carcinoma (n = 22) cohorts were matched for age and sex, while squamous cell carcinoma tumor volume was larger (P = .001). The best classification model achieved similar accuracies for training (17 squamous cell carcinomas, 16 inverted papillomas) and validation (7 squamous cell carcinomas, 6 inverted papillomas) datasets of 90.9% and 84.6%, respectively (P = .537). For the combined training and validation cohorts, the machine-learning accuracy (89.1%) was better than that of the neuroradiologists' ROI review (56.5%, P = .0004) but not significantly different from the neuroradiologists' review of the tumors (73.9%, P = .060) or entire images (87.0%, P = .748).

CONCLUSIONS

MR imaging-based texture analysis has the potential to differentiate squamous cell carcinoma from inverted papilloma and may, in the future, provide incremental information to the neuroradiologist.

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.

Sinonasal papillomas in a private referral otorhinolaryngology centre: Review of 22 years experience

OBJECTIVES

To evaluate the clinical presentation, treatment outcome and follow-up of all patients managed with sinonasal papillomas (SP), at a tertiary private otorhinolaryngology centre in Caracas (Venezuela).

MATERIAL AND METHODS

We reviewed 94 patients with SP that were treated at our otolaryngology center, from July 1st 1993 to June 31st 2015. The demographic data, clinical features, radiological findings, anatomical origin, disease extension into the adjacent structures, surgical approaches performed, histopathology outcomes, recurrent risk, malignant transformation rate and coadjuvant therapies were assessed.

RESULTS

Sixty-five patients (69.1%) were male and 29 (30.9%) female with an average age of 44.5 years (range 9-80 years). All patients underwent endoscopic sinus surgery. The most commont histologic subtypes of SP were inverted papilloma (58 patients; 61.7%), fungiform papilloma (35 patients; 37.2%) and oncocytic papilloma (one patient; 1.1%). SP was associated in 2 patients with undifferentiated squamous cell carcinoma. Twelve patients (12.8%) had disease with extension beyond the sinus without associated malignancy. All these patients received adjuvant treatment with advanced techniques of radiotherapy. The mean duration of the follow-up period was 9 years and 2 months. Eighteen patients (19.1%) had recurrent disease during the entire course of follow-up.

CONCLUSIONS

Complete endoscopic surgical removal of SP is the treatment of choice. In less endoscopically accessible tumours, with peripheral extension or incompletely resected, Intensity Modulated Radiotherapy and Volumetric Modulated Arc Therapy may be indicated. Timely post-operative endoscopic follow-up with biopsy of suspected lesions is important for early detection of recurrences and associated malignancy.

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.

Postoperative value of serum squamous cell carcinoma antigen as a predictor of recurrence in sinonasal inverted papilloma

OBJECTIVES

Sinonasal inverted papilloma (IP) has several unfavourable characteristics and therefore requires careful monitoring. The goal of this study was to identify whether serum squamous cell carcinoma antigen (SCCa) could predict IP recurrence.

DESIGN

A retrospective cohort study.

SETTING

Department of otolaryngology/head and neck surgery, Erasmus Medical Centre, Rotterdam, the Netherlands.

PARTICIPANTS

One hundred and thirty patients with IP treated at our centre with SCCa measurements available were included.

MAIN OUTCOME MEASUREMENTS

Follow-up of patients with IP since 2005, recurrence was defined as new disease within primary localisation at least 3 months after adequate surgical removal. We analysed the association between IP recurrence and serum SCCa values measured preoperatively, postoperatively and during follow-up.

RESULTS

Preoperative SCCa values or values measured during follow-up were not associated with risk of recurrence. Postoperative SCCa was positively associated with the risk of recurrence (P < 0.001). Postoperative SCCa had a good discriminative ability for the identification of recurrence with an area under the curve of 80.9%.

CONCLUSION

Postoperative SCCa is strongly associated with risk of recurrence. This might help the surgeon in the postoperative setting by identifying high-risk patients and planning follow-up strategy tailored to the individual patient.

Survival outcomes after endoscopic resection for sinonasal squamous cell carcinoma arising on inverted papilloma

BACKGROUND

Sinonasal inverted papillomas (IPs) can be associated synchronously or metachronously to invasive squamous cell carcinoma (SCC) in 5% to 10% of cases. The purposes of the present study were to analyze the outcomes of patients with sinonasal SCC arising from inverted papilloma (IP-SCC) treated through an endoscopic approach and review the pertinent literature.

METHODS

The medical records of all patients treated for IP-SCC between 1997 and 2014 at 2 referral centers following a uniform policy were retrospectively analyzed.

RESULTS

Thirty-four patients fulfilled the inclusion criteria. The 5-year overall survival (OS), disease-specific survival (DFS), and recurrence-free survival (RFS) rates were 66.8 ± 0.99%, 71.2 ± 0.96%, and 73.1 ± 0.82%, respectively. Multivariate analysis revealed that the advanced pT classification (pT3 or greater), the high-grade of tumoral differentiation, the cranioendoscopic approach, and the recurrence of disease impacted negatively on survival rates.

CONCLUSION

The endoscopic approach provides encouraging oncologic outcomes for sinonasal IP-SCC, comparable to those observed with traditional external approaches while minimizing morbidity for patients. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.

Inverted Sinonasal Papilloma Masquerading as a Malignancy - Report of an Unusual Case

Inverted sinonasal papilloma (ISP) is a benign epithelial neoplasm arising from the Schneiderian membrane. We report a case of ISP in a 50-year-old male that clinically presented as a polypoid mass in the nasal cavity. Imaging studies revealed it to be an aggressive lesion showing intracranial extension. On histopathological examination of the excised specimen, a diagnosis of ISP was arrived at. However, an extensive sampling of the tissue revealed no evidence of any malignant transformation. Taking into account the suggested viral aetiology for such lesions and the aggressiveness observed in this case, human papillomavirus (HPV) profiling was done but it turned out to be negative. Only one other case of inverted sinonasal papilloma arising from the nasal cavity and involving the brain has been reported in the literature to date. Considering the alarming clinical course in spite of its benign nature, it is important for the pathologist and surgeon to be well informed about this lesion.

Low-Grade Epithelial Proliferations of the Sinonasal Tract

Low-grade epithelial proliferations of the sinonasal tract include Schneiderian papillomas, respiratory epithelial adenomatoid hamartoma, seromucinous hamartoma and low-grade non-intestinal adenocarcinoma. There is considerable overlap in their clinical presentation, endoscopic appearance, and imaging features. Although well-described diagnostic criteria exist, a definitive diagnosis may be difficult to reach on a small biopsy. Schneiderian papillomas are divided into fungiform, inverted, and oncocytic types, each with characteristic clinical and morphological features. The latter two may progress to malignancy. The majority are still considered to be HPV-related. Two lesions are designated as hamartomas, but their pathogenesis remains uncertain, with inflammatory and neoplastic origins proposed. Respiratory epithelial adenomatoid hamartoma is increasingly being recognized for its association with chronic rhinosinusitis and olfactory cleft site of origin. Seromucinous hamartoma has gained attention in recent years and overlaps with both respiratory epithelial adenomatoid hamartoma and low-grade non-intestinal adenocarcinoma. Controversy surrounds their distinction, particularly from low-grade adenocarcinoma. The latter generally is cured by complete excision, with a 26 % risk of recurrence but rare metastases and deaths from disease.