Loss of p16 expression is a risk factor for recurrence in sinonasal inverted papilloma.

BACKGROUND: The purpose of this study was to evaluate p16, p53, EGFR, pEGFR protein expression and HPV infection as possible markers of tumor progression in a series of sinonasal inverted papilloma (SNIP) and sinonasal squamous cell carcinoma (SNSCC). METHODS: A series of 49 SNIP, 11 SNSCC associated with SNIP (SNIP-SNSCC) and 52 SNSCC not associated with SNIP were analyzed for p16, p53, EGFR, and phosphorylated EGFR (pEGFR) expression by immunohistochemistry. Human papillomavirus (HPV) infection status was evaluated by DNA-PCR. Results were correlated to clinical and follow-up data. RESULTS: Reduced or loss of p16 expression was observed in 18% SNIP, 64% SNIP-SNSCC and 87% of SNSCC. Reduced or loss p16 staining in SNIP correlated with shorter recurrent SNIP-free follow-up. In contrast, p16 expression was not predictive of recurrent SNSCC in cases with SNIP-SNSCC and SNSCC. P53, EGFR, and pEGFR expression did not differ between the tumor groups, nor were they related to recurrent SNIP-free follow-up or recurrent SNSCC. Oncogenic HPV types 16 and 18 were detected in 5% of SNIP and 18% of SNIP-SNSCC, but not in SNSCC. There was no correlation between HPV infection and >70% p16 immunostaining. CONCLUSIONS: HPV infection appears to play a minor role in SNIP and SNSCC and p16 immunostaining does not appear a valid surrogate marker for HPV. However, reduced or loss p16 expression may have prognostic value as a risk marker for recurrent SNIP.

HPV-Associated Benign Squamous Cell Papillomas in the Upper Aero-Digestive Tract and Their Malignant Potential.

Squamous cell papilloma (SCP) in the upper aero-digestive tract is a rare disease entity with bimodal age presentation both at childhood and in adults. It originates from stratified squamous and/or respiratory epithelium. Traditionally, SCPs have been linked to chemical or mechanical irritation but, since the 1980s, they have also been associated with human papillomavirus (HPV) infection. Approximately 30% of the head and neck SCPs are associated with HPV infection, with this association being highest for laryngeal papillomas (76-94%), followed by oral (27-48%), sinonasal (25-40%), and oropharyngeal papillomas (6-7%). There is, however, a wide variation in HPV prevalence, the highest being in esophageal SCPs (11-57%). HPV6 and HPV11 are the two main HPV genotypes present, but these are also high-risk HPVs as they are infrequently detected. Some 20% of the oral and oropharyngeal papillomas also contain cutaneous HPV genotypes. Despite their benign morphology, some SCPs tend to recur and even undergo malignant transformation. The highest malignant potential is associated with sinonasal inverted papillomas (7-11%). This review discusses the evidence regarding HPV etiology of benign SCPs in the upper aero-digestive tract and their HPV-related malignant transformation. In addition, studies on HPV exposure at an early age are discussed, as are the animal models shedding light on HPV transmission, viral latency, and its reactivation.

Impact of human papillomaviruses (HPV) on recurrence rate and malignant progression of sinonasal papillomas.

Sinonasal papillomas are characterized by their potential for frequent recurrences and malignant progression. Currently, the role of human papillomavirus (HPV) infection in sinonasal papillomas is unclear. A study was conducted to elucidate the impact of HPV infection on recurrence and malignant progression of sinonasal papillomas. One hundred and seven patients with 151 tumors could be examined. One hundred and one patients suffered from benign papilloma, mostly inverted papillomas (IP); six patients suffered from carcinomas in situ and squamous cell carcinomas (SCC) ex-IP. Recurrent IP were more often HPV-positive than non-recurrent tumors (38.8% vs. 60%-65%). Low-risk (LR) HPV infection (especially HPV 6) increased the risk of tumor recurrences (p = 0.0385 and p = 0.0556, respectively). IP and oncocytic papillomas (both lesions are known for their malignant potential) were more often high-risk (HR) HPV-positive (15.5% and 16.7%) than fungiform papilloma (which usually does not progress to carcinoma). CIS and SCC ex-IP displayed higher HPV rates than benign IP (83.3% vs. 38.8%), especially higher rates of HR-HPV (66.7% vs. 23.8%, p = 0.0415). Data from this study endorse the hypothesis that recurrence of sinonasal papillomas is promoted by LR-HPV infection and that malignant progression of IP is promoted by HR-HPV infection.

Association Between Human Papilloma Virus Infection and Malignant Sinonasal Inverted Papilloma.

OBJECTIVE: This systematic review and meta-analysis aimed to evaluate the risk of malignant sinonasal inverted papilloma (SNIP) according to the type of human papilloma virus (HPV) infection. METHODS: The databases of PubMed, EmBase, and Web of Science were searched for studies that reported the risk of malignant SNIP in patients infected by specific types of HPV. The quantitative analyses for pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Twenty-six molecular epidemiological studies that recruited a total of 900 patients with SNIP were selected for the final meta-analysis. The summary ORs indicated that HPV-6 (OR: 2.02; 95% CI: 0.47-8.61; P = .343), HPV-11 (OR: 0.86; 95% CI: 0.26-2.89; P = .806), and HPV-6/11 (OR: 1.44; 95% CI: 0.59-3.53; P = .426) infections were not associated with the risk of malignant SNIP. However, the risk of malignant SNIP was increased in patients infected with HPV-16 (OR: 8.51; 95% CI: 3.36-21.59; P < .001), HPV-11/16 (OR: 7.95; 95% CI: 1.13-56.01; P = .038), HPV-18 (OR: 23.26; 95% CI: 5.27-102.73; P < .001), and HPV-16/18 (OR: 24.34; 95% CI: 5.74-103.18; P < .001). CONCLUSIONS: This study found that patients infected with HPV types 16, 11/16, 18, and 16/18 were associated with an increased risk of malignant SNIP. However, patients infected with HPV types 6, 11, and 6/11 did not have a significant risk of malignant SNIP. Laryngoscope, 131:1200-1205, 2021.

Expression of Sp100 Protein in Human Papillomavirus-Associated Sinonasal Inverted Papilloma.

OBJECTIVE: Sinonasal inverted papilloma (SNIP) is a benign tumor characterized by an aggressive growth, a tendency to recur, and an association with malignancy. However, the precise etiology of SNIP is still unknown. The objective of this study was to identify the expression pattern of speckled protein 100 (Sp100) in the malignant transformation (MT) of SNIP and its correlation with human papillomavirus (HPV)-16 and HPV-18 infections and other clinical features. This would further help in understanding the possible mechanisms for the development of SNIP. METHODS: Individual nasal mucosa specimens from 40 patients (25 males and 15 females) and 10 inferior turbinate specimens as controls were included in the present study. The samples were divided into several sections for histopathological examination, HPV DNA detection, and immunohistochemical staining. RESULTS: We observed that as SNIP progressed, the Sp100 protein expression was gradually downregulated, and SP100 localization changed from nucleus to the cytoplasm. Positive rate of HPV infection in the SNIP with MT group was higher than that in the other groups, and Sp100 expression was correlated to HPV infections and SNIP with MT. However, no correlation was observed between Sp100 expression and clinical features, such as age, gender, and smoking. CONCLUSION: Positive rate of HPV infection is high in the SNIP with MT and has a correlation with Sp100 expression. In addition, the expression of Sp100 is downregulated in SNIP with MT, and Sp100 may play a role in the progression of SNIP.

The role of human papillomavirus in the pathogenesis of sinonasal inverted papilloma: a narrative review.

Sinonasal inverted papillomas (IPs) are rare tumours arising from the nasal epithelial mucosa. Most lesions are benign, but a subset of IPs progress to dysplasia and squamous cell carcinoma. Although the epidemiology and clinical features of IPs are well known, the pathogenesis is still unclear. Given the established role of human papillomaviruses (HPVs) in the formation of other mucosal tumours including cervical and oropharyngeal cancer, some have suggested the virus may play a role in IP development. However, the association between HPV and IPs has not yet been proven, and the variable detection of HPV DNA in IPs has cast uncertainty on whether the virus plays a major role in pathogenesis. In this review, we summarize early clinical reports and synthesize recent studies that may elucidate the association between HPV and IPs. We also discuss the role HPV may have in the progression of benign IP to dysplasia and malignancy, as well as potential pathological mechanisms. We hope that synthesizing the initial and recent studies on this topic will not only lead to a better understanding of research in the role of HPV in IP development, but also help guide and contextualize future studies.

Human papilloma virus induced oropharyngeal inverted papilloma as a precursor to laryngeal papillomatosis in A 1 year old child.

Inverted papillomas are rare tumors in the pediatric population and have not been reported in children less than two years. These tumors may produce respiratory distress in patients, particularly if they ectopically occur in the airway. Human papilloma virus is one of the known etiologies for many head and neck neoplasms including inverted papillomas and squamous papillomas. We report a child who was surgically treated at fifteen months of age for inverted papilloma of the pharynx who subsequently developed squamous papilloma of the larynx which persisted as a recurrent respiratory papillomatosis. This is the first such reported case to our knowledge.

P16 detection in benign, precursor epithelial lesions and carcinomas of head and neck.

BACKGROUND: Human papillomavirus (HPV) had recently been implicated in the pathogenesis of Head and Neck SCCs. The biological role of HPV in benign and pre-cancerous lesions is far less studied. p16 is a widely accepted marker to detect immonohistochemically the presence of HPV. METHODS: We evaluated, immunohistochemically, expression of p16 in 212 specimens: glottis, supraglottis, oropharynx, nasal/paranasal, with various diagnoses: hyperplasia, polyp/nodule, keratosis, papilloma, inverted papilloma, dysplasia, cancer (SCC). Analysis was completed according to location and disease. RESULTS: Hyperplasias/polyps were all negative for p16. A small percentage of papillomas was p16+ regardless of their location (12.5 %), the majority of inverted papillomas were p16+ (78.6 %) and statistically significant (p < 0.04). In carcinomas, 18/59 were p16+ (30.5 %): nasal/paranasal SCCs had a significantly higher percentage of p16+ cancer cells compared to glottis (p = 0.009), while tumours of the supraglottis/oropharynx had an intermediate score for p16+ cells (p = 0.07). Dysplasias were p16+ in 9/64 (14 %) regardless of grading (p = 0.03 compared to carcinomas). CONCLUSION: p16 was highly detected in inverted papillomas and in certain anatomic sites; however, it failed to be traced in benign lesions and only rarely encountered in dysplasias.

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.

EGFR mutation and HPV infection in sinonasal inverted papilloma and squamous cell carcinoma.

BACKGROUND: To evaluate the involvement of EGFR signalling and HPV infection in a cohort of inverted sinonasal papilloma (ISP) and sinonasal squamous cell carcinoma (SNSCC) and their value for prognosis and clinical treatment. METHODS: We analysed 55 ISP, 14 SNSCC associated with ISP (SNSCC-isp) and and 60 SNSCC not associated with ISP (SNSCC-novo) for EGFR gene mutation and copy number gain, protein expression of EGFR and phosporylated EGFR (pEGFR), and HPV-infection and KRAS mutation. Findings were correlated to clinico-pathological and follow-up data. RESULTS: We found EGFR exon 20 mutations in 38% (7/18) ISP, in 50% (6/12) SNSCC-isp and in 5% (1/19) SNSCC-novo. EGFR was expressed in 92% of ISP, while pEGFR was observed in 54% (21/39). SNSCC-isp and SNSCC-novo demonstrated comparable expression of EGFR (57% and 33%) and of pEGFR (44% and 38%). We observed an inverse relation between EGFR exon 20 mutation and pEGFR expression. Four of 39 (10%) ISP carried HPV-16. Oncogenic HPV was detected in 3/12 (25%) SNSSC-isp and in 1/8 (13%) SNSCC-novo. KRAS mutations were not detected in any of the samples. HPV infection was inversely correlated with pEGFR expression but not with EGFR mutation. ISP with EGFR activation by mutation or by phosphorylation had longer ISP-free survival, however, neither EGFR exon 20 mutation, pEGFR expression nor HPV infection demonstrated prognostic value in SNSCC. CONCLUSIONS: EGFR exon 20 mutation is frequent in ISP and SNSCC-isp, while activation of EGFR through phosphorylation also plays an important role. Our data indicate that a large proportion of SNSCC patients could benefit from therapy with modern EGFR inhibitors.

High prevalence of human papillomavirus infection in sinonasal inverted papilloma: a single-institution cohort of patients.

BACKGROUND: Both the prevalence of sinonasal inverted papilloma (IP) and the causal association with alpha-human papillomaviruses (alpha-HPVs) are controversial. In this study we aimed to determine HPV status in histologically selected, microdissected, formalin-fixed, and paraffin-embedded tissue samples of IP. METHODS: HPV status was assessed retrospectively by polymerase chain reaction (PCR)-bead-based multiplex genotyping on tissue samples of patients diagnosed with IP and consecutively treated with endoscopic resection. Forty-one HPV genotypes were considered, distinguishing between high risk and low risk. HPV status was correlated with demographics and clinical variables. Sixty sinonasal IP tissue samples were initially considered. After exclusion of 5 cases due to insufficient quality/quantity of the samples, 55 patients were included for analysis. RESULTS: HPV-DNA sequences were identified in 34 of 55 (61.8%) IPs, with a higher prevalence of high-risk than low-risk HPV genotypes (19 [55.9%] and 15 cases [44.1%], respectively). HPV16 strongly prevailed among the high-risk HPV cases (84.2%), and HPV54 prevailed among the low-risk HPV cases (53.3%). IPs with origin within the maxillary sinus were significantly associated with high-risk HPV (p = 0.019). No significant associations emerged between HPV status and demographics or clinical variables. CONCLUSION: In a series of 55 IP tissue samples, HPV-DNA sequences were identified in 61.8% of cases, which differs from the data of previous investigations. Further case-control studies are advocated to confirm this prevalence in the Italian population addressed, and also to clarify any pathogenic involvement of HPV in the natural history of IPs.

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.

Human Papillomavirus and Factors Associated with Recurrence in Sinonasal Inverted Papillomas from Poland and Spain.

Sinonasal inverted papilloma (SNIP) is a benign but locally aggressive tumor that has a tendency for recurrence and malignant transformation. The role of human papillomavirus (HPV) in SNIP is controversial. To determine the HPV-DNA prevalence and type distribution in SNIP in two different geographic areas and assess the association between SNIP recurrence and HPV infection, as well as additional potential etiologic factors. Two retrospective cohorts of SNIP patients from Poland and Spain were evaluated. Demographic, tobacco/alcohol use, clinical, and follow-up data were collected. All samples were subject to histopathologic evaluation, DNA quality control, and HPV-DNA detection by PCR. HPV-DNA positive samples and a random sample of HPV-DNA negative cases were further subject to p16INK4a analysis. Proportional-hazards models were used to evaluate the risk of recurrence by selected variables. Seventy-nine SNIP patients (46 from Spain diagnosed between 1995 and 2014, and 33 from Poland diagnosed between 2012 and 2017) were included in the study. HPV-DNA was detected in four patients (5.1%), two from each region, and all four were positive for the HPV11 subtype. Seventeen patients (21.5%) experienced recurrence, with a median time to recurrence of 14 months. No association was identified between lesional HPV-DNA positivity, toxic habits, Krouse stage, or malignant transformation and a higher risk of recurrence. The low prevalence of HPV-DNA in SNIPs suggests that HPV is not a main etiology for development of these lesions. With a lack of association between the evaluated factors and recurrence, further research with larger number of patients and additional biomarkers is warranted to further understand predisposing risk factors.

Transcriptionally Active HPV and Targetable EGFR Mutations in Sinonasal Inverted Papilloma: An Association Between Low-risk HPV, Condylomatous Morphology, and Cancer Risk?

Sinonasal inverted papillomas (IPs) commonly recur, and transform to malignancy in 5% to 10% of patients. It has long been debated whether IPs are caused by high-risk or low-risk (lr) human papillomavirus (HPV) and whether the HPV is transcriptionally active. EGFR mutations have also been recently implicated in the pathogenesis of IP with an unclear relationship to HPV status. IP cases over a 10-year period were tested for p16 by immunohistochemistry and for transcriptionally active hrHPV and lrHPV by reverse-transcriptase real-time polymerase chain reaction and RNA in situ hybridization, respectively. EGFR tyrosine kinase domain Sanger sequencing was performed on all lrHPV RNA positive and 15 randomly selected lrHPV RNA negative IPs. Seven sinonasal nonkeratinizing squamous cell carcinomas (SCCs) without associated IP were included as controls. Of the 44 IPs, 5 (11.4%) were associated with SCC, all keratinizing type. All IPs and associated SCCs were negative for p16 and hrHPV. lrHPV RNA was detected in 5/42 (12%) cases, including 3/5 (60%) with associated SCC (P=0.009). All 5 lrHPV RNA positive IPs involved the nasal cavity, had a distinct, condylomatous morphology, and were EGFR wild-type. In contrast, 11/15 (73.3%) lrHPV RNA negative IPs that were sequenced had EGFR exon 19 or 20 mutations. All control nonkeratinizing SCCs were lrHPV RNA negative, but 5/7 (71.4%) were p16 and high-risk HPV RNA positive. This study shows that a subset of IPs involving the nasal cavity have transcriptionally active lrHPV, condylomatous morphology, and possibly increased risk of malignancy. Furthermore, lrHPV positivity is mutually exclusive with EGFR mutations, which suggests alternate mechanisms of pathogenesis.

Low prevalence of human papillomavirus infection in sinonasal inverted papilloma and oncocytic papilloma.

The aim of this study was to investigate the role of human papillomavirus (HPV) in sinonasal inverted papilloma (SIP) and sinonasal oncocytic papilloma (SOP) from a single institution and whether p16 can serve as a surrogate marker for HPV infection. This study included 49 subjects with SIP and 36 subjects with SOP. Formalin-fixed paraffin-embedded tissues were used to extract genomic DNA, and HPV detection was performed by utilizing a valid nested polymerase chain reaction approach that can detect all known HPV subtypes. Immunohistochemistry was used to evaluate the expression of p16 in all tumor sections. The presence of HPV DNA was found in 6.1% (3/49) of the SIP patients and 11.1% (4/36) of the SOP patients. All identified HPV subtypes in SIP were high-risk HPV, including HPV-16 (two patients) and HPV-58 (one patient). Regarding SOP, there were three patients positive for HPV-16 and one with low-risk HPV (type 6). In total, 11/49 (22.4%) SIP lesions and 10/36 (27.8%) SOP lesions were considered p16 positive, with p16 staining in more than 70% of tumor cells. There was only one SIP and one SOP that were positive for both HPV (high-risk HPV type 16) and p16 staining. HPV does not play an etiologic role in inverted papilloma or oncocytic papilloma of the sinonasal region. p16 immunostaining should not be used as a surrogate marker to evaluate the HPV infection status in these lesions.

Absence of high-risk human papilloma virus in p16 positive inverted sinonasal papilloma.

OBJECTIVES: Sinonasal inverted papilloma (SIP) is a relatively rare disease, and its etiology is not understood. It is characterized by locally aggressive growth and a strong tendency to recur despite its benign histology. AIMS: The aim of this study was to identify the presence of human papilloma virus (HPV) and its surrogate marker p16 in SIP tissue samples from a regional cohort. MATERIAL AND METHODS: Subjects were identified from our regional center cohort of 88 SIP patients treated between 1984-2014. From these subjects, 54 were included in this study. Of these, 53 biopsies were analyzed with PCR, and 54 samples were immunohistochemically stained for p16. DNA was extracted from histopathologically verified SIP. Genotype screening for 13 high risk-, 5 oncogenic and 6 low risk HPV types was performed using the PapilloCheck® HPV-screening test. RESULTS: HPV analysis was successful for 38 of 53 samples. Of the 38 successfully analyzed samples, only 2 samples were positive for HPV 11. Notably, p16 was present in the epithelia in all samples, and in the papilloma lesions in 37 samples. CONCLUSION: Since only 2 out of 38 SIPs were positive for HPV (type 11), and at the same time p16 was positive in epithelia in all samples and in 37 of 38 papilloma lesions of the samples, it is concluded that p16 cannot be used as a surrogate marker for high-risk HPV-infection in SIP. We are currently planning a prospective, multicenter study in order to increase the study power and in order to be able to better evaluate the clinical implications of HPV-and p16 in SIP.

Human papillomavirus and infiltration of CD8- and Foxp3-positive immune cells in sinonasal inverted papillomas.

Background: Sinonasal inverted papilloma (IP) is a benign tumor with a high risk of local recurrence and a potential to malignify and Human papillomavirus (HPV) has been suggested an etiological factor. p16INK4a (p16) overexpression is considered a surrogate marker for HPV, but whether p16 and HPV correlate to IP is uncertain. Besides, a prognostic role of tumor infiltrating lymphocytes (TILs) are observed in many tumors, however their role in IP is sparsely studied. Aims/objectives: We hence analyzed IPs for the presence and the prognostic role of HPV and p16 overexpression together with CD8+ and FoxP3+ TILs in a population-based study. Material and methods: 98 IP patients diagnosed 2001-2010 were identified from the Swedish Cancer Registry and analyzed for HPV by PCR and p16, CD8 and FoxP3 was by immunohistochemistry. Results: In total, 12.2% of the IPs were HPV-positive (nine HPV-11, two HPV-6 and one HPV-45). Patients with HPV-positive lesions were younger (p = .003) and tended to present with more dysplasia. No correlation was observed between TILs and prognosis. Conclusions and significance: Our data suggests that patients with HPV-positive IPs present with different clinical characteristics, suggesting possibly different disease entities. Moreover, recurrences may occur >5 years, which should be considered in the follow-up.

[Human papillomavirus and Epstein-Barr virus in the pathogenesis of inverted papilloma and associated sinonasal carcinoma]. / Virusy papillomy cheloveka i Épshteina-Barr v patogeneze invertirovannoi papillomy i assotsiirovannoi s nei sinonazal'noi kartsinomy.

OBJECTIVE: To determine whether Epstein-Barr virus and human papillomavirus (HPV) types 6, 11, 16, 18, 35, and 43 DNA can be present in inverted papilloma (IP) and associated sinonasal carcinoma. MATERIAL AND METHODS: The investigation was carried out using tissue samples obtained during surgery from 76 cases of IP and 4 cases of sinonasal carcinoma that had developed in the presence of IP. PCR was performed in 41 cases of IP and in 4 cases of sinonasal carcinoma; immunohistochemistry was done in 15 cases of IP to identify HPV L1 capsid protein. RESULTS: HPV6 DNA was detected in 20 cases; three of them were simultaneously found to have also HPV11; 1 case had only HPV11. HPV types 16, 18, 35, and 45 and Epstein-Barr virus were not detected. PCR revealed HPV types 16 and 35 in one of the 4 cases of sinonasal carcinoma associated with IP. Immunohistochemical study identified HPV L1 capsid protein in the epitheliocytes and stromal infiltrating lymphocytes and macrophages in two cases of IP with the highest concentration of HPV DNA as evidenced by PCR, as well as in one case of sinonasal carcinoma. CONCLUSION: Taking into account the low HPV DNA concentration detected only for types 6 and 11, as well as the immunohistochemical detection of HPV L1 in the tumor stromal lymphocytes and macrophages and some basal epitheliocytes in individual cases, it can be assumed that HPV does not play a crucial role as an etiological factor for IP. PCR revealed oncogenic HPV types 16 and 35 in sinonasal carcinoma associated with IP only in one case, which makes it untimely to claim that this virus plays a very special role in the etiology of this carcinoma. Epstein-Barr virus was not found in any case.

Human papillomavirus: An unlikely etiologic factor in sinonasal inverted papilloma.

OBJECTIVES/HYPOTHESIS: Tenuous evidence has supported the hypothesis that sinonasal inverted papilloma (SNIP) arise from human papillomavirus (HPV) infection. To clarify the role of HPV in SNIP, all known HPV sub-types were evaluated by employing a robust polymerase chain reaction-based method in a wide variety of SNIPs from a single institution. STUDY DESIGN: Retrospective surgical specimen tumor sample analysis. METHODS: HPV positivity among SNIP samples and those with squamous cell carcinoma (SCC) were compared. Immunohistochemistry was used to quantify p16 (over)expression among tumors as a surrogate marker for HPV. RESULTS: HPV was detected in 10/76 (13%) SNIP specimens. Identified HPV subtypes included nononcogenic 6 and 11 (6/76, 8%) and oncogenic 16, 18, 45, 56 (4/76, 5%). There was no HPV positivity among SCC samples. Only 4/10 (40%) HPV + samples had > 75% p16 cell staining. CONCLUSION: HPV is not supported as an etiological driver of SNIP development or progression to SCC. The p16 biomarker is not a sensitive indicator of HPV positivity in SNIP. LEVEL OF EVIDENCE: NA Laryngoscope, 2443-2447, 2018.

Human Papilloma Virus (HPV) in Sinonasal Papillomas and Squamous Cell Carcinomas: A PCR-based Study of 60 cases.

This study was carried out to observe the association of Human Papilloma Virus (HPV) with papillomas and squamous cell carcinomas of the sinonasal region. The present study was a hospital-based study conducted over a period of three years from May, 2014 to May, 2017 in the Department of Pathology, Government Medical College, Srinagar. A total of 196 cases of non-neoplastic and neoplastic lesions of nasal cavity and paranasal sinuses were observed during the study period. Out of total 196 cases, 102 were non-neoplastic and 94 were neoplastic. Of the 94 neoplastic lesions, 58 were benign and 36 were malignant. A total of 60 cases which included 38(63.33%) inverted papillomas, 12(20%) exophytic papillomas and 10 (16.66%) squamous cell carcinomas were included in the present study for HPV association. We studied the association of HPV with sinonasal papillomas and squamous cell carcinomas by polymerase chain reaction (PCR). HPV positivity was seen in 5(13.16%) out of 38 cases of inverted papillomas, whereas 4 out of 12(33.33%) exophytic papillomas tested positive for HPV. Out of 10 squamous cell carcinomas HPV positivity was seen in 2(20%) cases. Low risk HPV types 6 and 11 showed an association with sinonasal papillomas and oncogenic HPV types 16 and 18 with squamous cell carcinomas.