Is there an occupational etiology of inverted papilloma of the nose and sinuses?

Etiology of sinonasal inverted papilloma: An update

Objective

Sinonasal inverted papilloma (IP) and its clinical features have been widely studied, but there are few studies delving into its etiology and risk factors. A narrative review was conducted to summarize a contemporary understanding of the potential etiologies of IP, including immunologic/inflammatory, viral, genetic, and environmental causes.

Study Design

Review.

Methods

A MEDLINE search was conducted through August 11, 2021, focusing on studies investigating the etiology and risk factors for sinonasal IP and its malignant transformation.

Results

High‐ and low‐risk human papillomavirus have been connected with the formation of IP, but conflicting evidence exists regarding their role. Occupational and industrial exposures may also contribute to IP formation, while smoking may increase the odds of malignant progression. Exon 20 mutations in EGFR are an active area of research in IP with mixed evidence. Finally, several cell cycle and angiogenic factors such as Ki67, VEGF, and Akt/mTOR have been implicated in the development and progression of IP.

Conclusion

There continues to be conflicting evidence around the development of IP, but significant progress has been made in recent years. Further study is needed for all these potential etiologies to elucidate risk factors and therapeutic strategies.

Sinonasal inverted schneiderian papilloma presenting as a large intraoral lesion

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

Clinical Implications of Carcinoma In Situ in Sinonasal Inverted Papilloma

Objective

Sinonasal inverted papilloma (IP) is a typically benign sinonasal tumor with a tendency to recur and the potential for malignant transformation. Varying degrees of dysplasia may be present, of which carcinoma in situ (CIS) is most advanced. We hereby describe the biological and clinical behavior of IP with CIS (IPwCIS).

Study Design

Retrospective cohort.

Setting

Tertiary academic referral center.

Subjects and Methods

Patients who underwent surgical resection for IP between 2002 and 2017. Pertinent clinical data were obtained, and all IPwCIS cases were histologically confirmed.

Results

In total, 37 of 215 cases (17.2%) were identified with IPwCIS. Mean age was 57 years and 86.5% of patients were male. Median follow-up was 82 months, and the recurrence rate was 27%. The maxillary sinus was the most common primary site (37.8%) and 14 tumors (37.8%) demonstrated multifocal attachment, which was associated with recurrence (odds ratio [OR], 9.7; 95% confidence interval [CI], 1.4-112.8; P = .028). IPwCIS was also associated with multiple recurrences (OR, 2.71; 95% CI, 1.246-5.814; P = .021). Most patients were treated with surgery alone (89.1%) and 4 patients received adjuvant radiotherapy (8.1%). Only 1 patient (2.7%) demonstrated malignant transformation after definitive surgery.

Conclusions

IPwCIS represents the most severe degree of dysplasia prior to malignant transformation and is associated with higher recurrence rate and multifocal involvement but low rate of conversion to invasive carcinoma. The need for adjuvant therapy remains controversial, and further research into the etiology of the disease is warranted.

Comprehensive analysis of HPV infection, EGFR exon 20 mutations and LINE1 hypomethylation as risk factors for malignant transformation of sinonasal-inverted papilloma to squamous cell carcinoma

Different risk factors are suspected to be involved in malignant transformation of sinonasal papillomas and include HPV infection, tobacco smoking, occupational exposure, EGFR/KRAS mutations and DNA methylation alterations. In our study, 25 inverted sinonasal papillomas (ISPs), 5 oncocytic sinonasal papillomas (OSP) and 35 squamous cell carcinomas (SCCs) from 54 patients were genotyped for 10 genes involved in EGFR signalling. HPV-DNA detection was performed by in-situ hybridisation and LINE-1 methylation was quantitatively determined by bisulphite-pyrosequencing. High-risk HPV was observed only in 13% of ISP-associated SCC and in 8% of de novo-SCC patients. EGFR mutations occurred in 72% of ISPs, 30% of ISP-associated SCCs and 17% of de novo-SCCs. At 5-year follow-up, SCC arose in only 30% (6/20) of patients with EGFR-mutated ISPs compared to 76% (13/17) of patients with EGFR-wild-type ISP (p = 0.0044). LINE-1 hypomethylation significantly increased from papilloma/early stage SCC to advanced stage SCC (p = 0.03) and was associated with occupational exposure (p = 0.01) and worse prognosis (p = 0.09). In conclusion, our results suggest that a small subset of these tumours could be related to HPV infection; EGFR mutations characterise those ISPs with a lower risk of developing into SCC; LINE-1 hypomethylation is associated with occupational exposure and could identify more aggressive nasal SCC.

Distinctive expression profiles of Caveolin-1 and Notch-1 protein in patients with nasal polyps or sinonasal inverted papillomas

BACKGROUND

Nasal polyposis (NP) and sinonasal inverted papillomas (SIP) are considered benign lesions capable of recurrence or malignant transformation although not with the same prevalence. Since fluctuations of Caveolin-1 and Notch-1 proteins expression have been reported in many pathologies, the current study aimed to investigate their involvement in the epithelial transformation observed in SIPs compared to NP.

METHODS

Immunohistochemical expression of Caveolin-1 and Notch-1 proteins was assessed in 104 patients with sinonasal lesions (45 NP, 45 SIP and 14 NP with SIP), semiquantively (percentage times intensity). Proteins expression profiles were evaluated statistically for their correlation with patients demographic and clinicopathological variables (grade of dysplasia, inflammation, recurrence) as well as with markers of proliferation (Ki67) and apoptosis (7-AAD) as determined by flow cytometry analysis.

RESULTS

SIP lesions presented increased Caveolin-1 immunopositivity compared to NP (62.2%, vs 40.9%; p = 0.045). Cytoplasmic staining was observed only in epithelium's basal and suprabasal layers. Caveolin-1 positivity was not related to Ki67 expression, apoptosis, inflammation or dysplasia, eventhough 81.8% of highly immunopositive lesions were dysplastic (p = 0.03). Also, smokers presented significantly increased immunopositivy (p = 0.03). In contrast SIP lesions presented reduced Notch-1 expression compared to NP (68.9% vs 100%; p < 0.001). Dysplastic lesions presented low Notch-1 immunopositivity (p < 0.001). Enhancement of Notch-1 gene expression was also associated with inflammation.

CONCLUSIONS

The herein presented data suggest that the expression profiles of Caveolin-1 and Notch-1 proteins in sinonasal pathologies are distinctive and that could be explored as potential targets for the development of alternative therapeutic approaches.

Genetic mutation analysis of the malignant transformation of sinonasal inverted papilloma by targeted amplicon sequencing

BACKGROUND

The mechanism underlying the malignant transformation of inverted papilloma (IP) has not yet been elucidated.

METHODS

To clarify the genes responsible for the malignant transformation, we analyzed 10 cases of IP, 8 of IP with dysplasia, and 11 of squamous cell carcinoma (SCC) by targeted amplicon sequencing.

RESULTS

The number of mutant genes increased in the order of IP < dysplasia < SCC. Significant differences were observed in the mutation rates of three genes (KRAS, APC and STK11) in particular. TP53 was altered frequently in each group and might be involved in malignant transformation based on to the site of the mutation. A comparison of the genetic variants by region of IP tissue among patients with IP alone, and those with dysplasia or SCC revealed significant differences in the mutation rate of the KRAS gene.

CONCLUSION

Identification of genetic mutations in KRAS is effective for predicting the malignant transformation of IP.

Endoscopic Resection of Inverted Papilloma: University of Miami Experience

Background

The aim of this study was to evaluate the efficacy and safety of endoscopically resecting paranasal sinus inverted papillomas at a tertiary medical center.

Methods

Over a 9-year period, 51 patients with a diagnosis of inverted papilloma underwent endoscopic resection at the University of Miami/Jackson Memorial Medical Center. The study group consisted of 14 women and 37 men with a mean age of 59 years (range, 20–88 years) enrolled in a clinical data base. All of the patients were followed endoscopically at regular intervals on an outpatient basis.

Results

Endoscopic evidence of extensive papillomas involving the anterior and posterior ethmoid sinuses and at least one (usually the maxillary) dependent sinus was found in 60% of the cases. Extensive radiological disease (varying degrees of mucoperiosteal thickening or opacification of all five cavities) was evident in 50% of the cases. All but two had unilateral disease. An association with chronic inflammatory polyps (clinically and pathologically) was observed in 25 of 51 patients (49%). Follow-up ranged from 6 to 99 months (mean, 30 months). There have been seven recurrences (14%). Four of these have been managed in the office under topical anesthesia. Three recurrences were managed surgically in the operating room. All of the patients have been free of disease. Complications included an intraoperative CSF leak (three patients); temporary infraorbital hypesthesia (three patients); periorbital ecchymosis, hematoma, or cheek edema (four patients); and orbital symptoms (two patients). Carcinoma was found in four patients (8%) who received postoperative radiotherapy and remain free of disease.

Conclusion

The endoscopic approach continues to provide at least equivalent short-term results as compared with external techniques for the removal of paranasal sinus inverted papilloma. The final cavity should allow for adequate postoperative surveillance and potential resection of recurrences in the office setting, without the need for a return to the operating room in most patients. The association of inverted papilloma with chronic inflammatory polyps and tobacco use warrants additional study.

Sinus Inflammation Associated with Contralateral Inverted Papilloma

Objective

To assess with computerized tomography (CT) the association of unilateral inverted papilloma (IP) and contralateral sinus inflammation.

Design

Retrospective analysis of CT findings in a sample of patients with unilateral IP, a sample with other unilateral sinonasal tumors, and normal controls.

Patients and Methods

Sixteen patients with unilateral IP comprised the study population. Nine patients with other unilateral sinonasal tumors (five with squamous papilloma, two with squamous cell carcinoma, and one each with adenocarcinoma and large cell carcinoma) were used as a comparison population. Patients undergoing maxillofacial CT for nontraumatic orbital conditions comprised the control sample (n = 12 sides). Each patient's preoperative CT scan was evaluated with a modified Lund-Mackay scoring system. The scores for the sides opposite the IPs were compared with the sides contralateral to other sinonasal tumors as well as to normal controls.

Results

Analysis of all three samples’ contralateral sides simultaneously using analysis of variance revealed a difference (p = 0.010). The contralateral sinus scores in IPs tended to be higher than the sides opposite the other sinonasal tumors (mean, 2.66 ± 1.07 versus 1.18 ± 0.76; p = 0.06). These in turn were higher than the normal controls (mean, 0.75 ± 0.48; p < 0.02).

Conclusions

Unilateral IPs are associated with contralateral inflammation as detected by CT. This degree of contralateral inflammation is greater than that seen in other sinonasal tumors. The etiology of this association is unclear. A recent histological review suggested IP is an inflammatory polyp and not a true papilloma. Our data further suggest inflammation may be involved in the pathogenesis of IP. Further work is needed to better understand the pathophysiology and behavior of IP and to define its relationship to sinus inflammation.

Inverted schneiderian papilloma of the supraglottis: Case report

Inverted schneiderian papillomas are rare benign tumors, most often arising from the sinonasal mucosa. We describe a case of a 59-year-old female with an inverted papilloma of the supraglottis. This is the first reported case of a supraglottic-presenting inverted papilloma. Although rare, this case demonstrates that these tumors should be considered during workup of supraglottic laryngeal masses. Laryngoscope, 127:2830-2832, 2017.

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.

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.

Transcriptional activity of HPV in inverted papilloma demonstrated by in situ hybridization for E6/E7 mRNA

OBJECTIVE

Assess human papilloma virus (HPV) transcriptional activity in inverted Schneiderian papillomas (IPs).

STUDY DESIGN

Case series with chart review.

SETTING

Academic tertiary care center.

SUBJECTS AND METHODS

Retrospective clinicopathologic review of 19 cases of IP in patients undergoing surgical excision from 1995 to 2013 at Mayo Clinic in Rochester, Minnesota. Surgical pathology archival material was histopathologically reviewed using hematoxylin and eosin-stained slides. Formalin-fixed, paraffin-embedded material from each case was evaluated for p16 expression using immunohistochemistry as well as HPV DNA and E6/E7 messenger RNA (mRNA) transcription using polymerase chain reaction (PCR) and in situ hybridization (via RNAscope technology), respectively.

RESULTS

Eight patients were female (42%), with an average age of 53 years (range, 23-82 years). Three demonstrated malignancy, and 5 subsequently recurred. Average follow-up was 49 months (range, 0-200 months), and 1 patient died from squamous cell carcinoma arising from the IP. RNAscope detected HPV mRNA transcripts exclusively within IP in 100% of cases; however, in 11 patients (58%), less than 1% of cells exhibited transcriptional activity. Only 2 of 19 cases (11%) demonstrated mRNA activity in 50% or more cells. HPV DNA was detected in only 2 specimens by PCR.

CONCLUSIONS

This study reveals wide prevalence but limited transcriptional activity of HPV in IP. No correlation between HPV transcriptional activity and progression, recurrence, or malignant transformation was identified. These data suggest that transcription of HPV may contribute to the pathogenesis of IP, but prospective data are needed to definitively demonstrate this connection. These results also suggest that RNAscope may be more sensitive than PCR in detecting HPV activity in IP.

Inverted papilloma involving the temporal bone and its association with squamous cell carcinoma: critical analysis of the literature

Inverted papilloma is a rare, benign neoplasm, which usually originates from the lateral nasal wall and can be locally aggressive, extending into surrounding structures. Unusually, this disease involves temporal bone. There have been only 18 reported cases in the literature. The available data regarding inverted papilloma of the temporal bone are reviewed, and its etiopathogenesis, recurrence rate and association with squamous cell carcinoma are discussed.

Late recurrence or secondary location? Towards a better understanding of the physiopathology of inverted papilloma

INTRODUCTION

Inverted papilloma (IP) is the most frequent benign tumor of the nasal cavities. Recurrence is found in 12 to 14% of cases, mainly at the primary site, although also exceptionally in remote locations. The present paper discusses the physiopathogenesis of IP on the basis of a report of late second occurrence of IP at a remote location and a review of the literature.

CASE REPORT

A man, who had undergone surgery in 1997 for ethmoid IP at the age of 56, presented 11 years later with nasal cavity IP at a second (frontal) location, discovered serendipitously during systematic follow-up and managed surgically without complication.

DISCUSSION AND CONCLUSION

The physiopathology of nasal cavity IP remains unexplained. No reliable histologic or biological markers predict risk of recurrence or of malignant transformation. The sole treatment is total surgical resection. The risk of local recurrence, often due to incomplete resection, is well known, but that of a secondary location is less so, and regular very long-term follow-up is justified.

Occupational risk factors for sinonasal inverted papilloma: a case-control study

OBJECTIVES

Sinonasal inverted papilloma (IP) is an uncommon benign tumour characterised by frequent recurrence and, in approximately 10% of cases, by neoplastic transformation. IP aetiology is unknown but human papillomavirus is detectable in about one quarter of tumours. As some occupational hazards have been reported to be possible risk factors for IP, the aim of this study was to assess risk for sinonasal IP associated with prior exposure to suspected occupational risk factors for sinonasal malignancies.

METHODS

Between 1996 and 2007, data on incident cases were collected from hospitals throughout the Piedmont region of Italy by the regional sinonasal cancer registry. A questionnaire on occupational history, completed by 127 cases and 337 hospital controls, was used to assign previous exposure to a list of 17 occupational hazards. The relationship between IP and cumulative exposure to these hazards was explored using unconditional logistic regression to statistically adjust for age, sex, area of residence, smoking and co-exposures.

RESULTS

The risk of IP was significantly increased for ever exposure to welding fumes (OR 2.14) and organic solvents (OR 2.11) after controlling for potential confounders. For organic solvents only, a significant association with continuous cumulative exposure and a significant trend in risk across ordered cumulative exposure categories was found.

CONCLUSIONS

The present study revealed a significant association and a significant dose-response relationship between occupational exposure to organic solvents and IP. The lack of a dose-response relationship for welding fumes suggests that the observed association with ever exposure should be interpreted with caution.

Skull base inverted papilloma: a comprehensive review

Skull base inverted papilloma (IP) is an unusual entity for many neurosurgeons. IP is renowned for its high rate of recurrence, its ability to cause local destruction, and its association with malignancy. This paper is a comprehensive review of the reports, studies, and reviews published in the current biomedical literature from 1947 to September 2010 and synthesize this information to focus on its potential invasion to the base of the skull and possible intradural extension. The objective is to familiarize the clinician with the different aspects of this unusual disease. The role of modern diagnostic tools in medical imaging in order to assess clearly the limits of the tumors and to enhance the efficiency and the safety in the choice of a surgical approach is pointed out. The treatment guidelines for IP have undergone a complex evolution that continues today. Radical excision of the tumour is technically difficult and often incomplete. Successful management of IP requires resection of the affected mucosa which could be achieved with open surgery, endoscopic, or combined approach. Radio and chemotherapy were used for certain indications. More optimally research would be a multicenter randomized trials with large size cohorts.

Inverted papillomas and benign nonneoplastic lesions of the nasal cavity

BACKGROUND

Benign lesions of the nasal cavity represent a diverse group of pathologies. Furthermore, each of these disorders may present differently in any given patient as pain and discomfort, epistaxis, headaches, vision changes, or nasal obstruction. Although these nasal masses are benign, many of them have a significant capacity for local tissue destruction and symptomatology secondary to this destruction. Advances in office-based endoscopic nasendoscopy have equipped the otolaryngologist with a safe, inexpensive, and rapid means of directly visualizing lesions within the nasal cavity and the initiation of appropriate treatment.

METHODS

The purpose of this study is to review the diagnosis, management, and controversies of many of the most common benign lesions of the nasal cavity encountered by the primary care physician or otolaryngologist.

RESULTS

This includes discussion of inverted papilloma (IP), juvenile angiofibroma, squamous papilloma, pyogenic granuloma, hereditary hemorrhagic telangiectasia, schwannoma, benign fibro-osseous lesions, and other benign lesions of the nasal cavity, with particular emphasis on IP and juvenile angiofibroma.

CONCLUSION

A diverse array of benign lesions occur within the nasal cavity and paranasal cavities. Despite their inability to metastasize, many of these lesions have significant capability for local tissue destruction and recurrence.

Prevalence of human papillomavirus, Epstein-Barr virus, p21, and p53 expression in sinonasal inverted papilloma, nasal polyp, and hypertrophied turbinate in Hong Kong patients

BACKGROUND

The purpose of this study of human papillomavirus (HPV), Epstein-Barr virus (EBV), p21, and p53 in sinonasal inverted papilloma (IP) was to help elucidate its pathogenesis.

METHODS

Seventy-three IPs, 48 nasal polyps, and 85 hypertrophied turbinates were subjected to HPV polymerase chain reaction (PCR) study. Seventy-three IPs, 30 nasal polyps, and 32 hypertrophied turbinates were subjected to EBV in situ hybridization (ISH), p21, and p53 immunohistochemical (IHC) studies.

RESULTS

HPV was positive in 3 of 73 IPs (4.1%). All specimens were EBV negative. In all, 99% of IPs showed strong and diffuse p21 nuclear reactivity. Most nasal polyps and hypertrophied turbinates showed weak to moderate immunoreactivity of the basal and parabasal cells. Only focal p53 immunoreactivity of the basal and parabasal cells was found in 19% of IPs and 40% of nasal polyps.

CONCLUSIONS

HPV prevalence of our IP is low. EBV is not present in IP. High p21 and low p53 expression in IP suggests a non-p53-dependent regulation pathway.

A Case-Control Study of the Risk Factors Associated with Sinonasal Inverted Papilloma

Background

The etiology of sinonasal inverted papilloma (IP) is unknown. This study was designed to evaluate the possible risk factors associated with IP

Methods

This is a case-control epidemiology study in a tertiary referral center. Fifty patients with IP and 150 matched controls were interviewed using a questionnaire on suspected risk factors. Univariate analysis of the risk factors and calculation of the matched odds ratios, the corresponding 95% CIs, and p values was performed. Significant risk factors were further studied using conditional logistic regression analysis.

Results

Outdoor and industrial occupations were associated with IP. Tobacco smoking, drinking alcohol, history of allergic rhinitis, sinusitis, nasal polyp, non-sinonasal papilloma and non-sinonasal malignancy were not significant factors.

Conclusions

Outdoor and industrial occupations were associated with IP and may be potential risk factors. Future studies are warranted to further evaluate the individual type of occupation and chemical involved.

[Sinonasal basaloid squamous cell carcinoma in biopsies of inverted papilloma]

Basaloid squamous cell carcinoma (BSCC) is a rare tumor representing an aggressive variant of squamous cell carcinoma (SCC) and arising from a common precursor cell. BSCC rarely originates from the sinonasal tract. We report on an 83-year-old woman with BSCC after multiple resections of an inverted papilloma (IP) of the left sinonasal tract. The tumor filled the nasal cavity completely and was infiltrating the ipsilateral frontal skull base and periorbita. Because of the tumor's expansion, the patient's age, and comorbidity, surgery was not performed, but primary radiotherapy was initiated. A possible association between sinonasal BSCC and IP, as implicated by the current case, must be further investigated. In any case, IP requires consequent endoscopic and, if necessary, radiological follow-up in order to detect recurrent disease or malignant transformation.

Inverted papilloma of paranasal sinuses

INTRODUCTION

Inverted papilloma (Schneiderian papilloma) is a primarily benign lesion that occurs in the nasal cavity and paranasal sinuses. Clinical problems include a tendency towards local destruction, recurrence and malignant transformation into squamous cell carcinoma. Hence, complete surgical removal is the therapy of choice and a meticulous follow-up is mandatory.

STUDY DESIGN

This is a review including a short introduction to the different histological types of nasal papilloma, their pathogenesis and the clinical and histopathological diagnosis. Staging systems, therapeutic approaches, and surgical concepts are discussed.

RESULT

The detection and definition of factors that allow a prognosis of recurrence or malignant transformation of inverted papilloma is an active field of research. The results of studies dealing with the definition of prognostic factors, that investigated immunohistochemical methods, virus detection, molecular genetics, and histomorphological studies are discussed including our own results on the prognostic value of histology. A concept for the diagnosis, management, therapy and follow-up of inverted papilloma is proposed.

[Inverted papilloma: treatment and evolution]

Inverted Papilloma is a frequent bening nasosinusal tumour. The high frequency of recurrences and the malignant potential are its clinical characteristics. We present our experience in a retrospective study done in the last 10 years. 10 patients with Inverted Papilloma have been treated during that period. According to the Classification made by krouse who divides the Inverted Papilloma in four stages, we found 3 in stage I, 6 in stage II and 1 in stage IV. The treatment in almost all of the patients in Stage I and II was endonasal surgery. External approach was performed for stage IV. The recurrence rate was 30% and malignization occurred in 10% of the cases. Finally, we have compared other publications, and revised the literature.

HPV infections in benign and malignant sinonasal lesions

This review updates the evidence that the human papillomavirus (HPV) is involved in the development of benign and malignant sinonasal lesions. Since the early 1980s, when evidence was provided on the possible involvement of HPV in the aetiology of both benign respiratory papillomas and squamous cell carcinomas, a substantial number of studies have explored this issue. To date, 33.3% of sinonasal papillomas and 21.7% of sinonasal carcinomas analysed have been shown to be positive for HPV. Many elements of the data parallel the observations made in HPV lesions at other mucosal sites, such as malignant transformation and frequent recurrence after radical treatment; the fact that low risk HPV types 6 and 11 are usually confined to benign lesions, whereas the reverse is true for the oncogenic HPV types 16 and 18; and the presence of squamo-columnar junctions and squamous cell metaplasia in the sinonasal system. The discrepancies reported by several studies might result in part from technical reasons, but it is also possible that sinonasal lesions have a heterogeneous aetiology (HPV related and non-related) and/or that some novel (yet unidentified) HPV types exist in these lesions, which are detected by some studies but not by others.

Schneiderian papillomas and carcinomas: a review

The ectodermally derived Schneiderian mucosa gives rise to an extremely varied collection of benign and malignant neoplasms. Prototypical of these are the Schneiderian papillomas (inverted, fungiform, and cylindrical cell) and their malignant counterparts. Human papilloma virus (HPV) is currently the leading candidate as a cofactor in the pathogenesis of the papillomas. Carcinomas arise in association with the papillomas in about a 10% frequency. The carcinomas may be synchronous or metachronous. Recurrences of the papillomas are the bane of surgeons. The magnitude of the recurrences is directly proportional to the completeness of removal with the best results obtained by techniques that afford the best operative exposure. A comparison of results by different surgical procedures is presented. Histologic features sought to predict recurrences or malignant transformation have, by and large, not been helpful. Keratinization and hyperkeratosis in papillomas, however, are suggested to be sufficiently ominous as to warrant further study.

Recurrence and malignant degeneration of 89 cases of inverted papilloma diagnosed in a non-tertiary referral population between 1975 and 1995: clinical predictors and p53 studies

Eighty-nine patients with sinonasal inverted papilloma presenting between 1975 and 1995 were reviewed with the aims of studying predictors of tumour behaviour and correlating outcome with p53 expression. Correlation of clinical, radiological features and p53 status was made using chi2 and multiple logistic regression analysis with recurrence and malignant degeneration as the main outcome measures. Two patients had synchronous malignancy but no malignant degeneration was seen. There was no significant difference in recurrence between minor intranasal procedures and more extensive surgery for the first event. Younger patients were more likely to recur. (P = 0.0493, odds ratio 0.43). Those who smoked showed a trend towards multiple recurrence. p53 was expressed in 41% but did not predict recurrence. Morbidity was related to the extent of surgery. Inverted papilloma presenting to a non-tertiary centre is more benign than previously reported. Initial management by less extensive endoscopic surgery may reduce morbidity.

Radiation therapy in inverted papillomas of the nasal cavity and paranasal sinuses

PURPOSE

Between December 1969 and September 1989, a total of 10 patients with advanced and/or recurrent inverted or cylindrical cell papillomas were treated with irradiation at the University of Florida in Gainesville.

MATERIALS AND METHODS

Nine of 10 patients had 1 or more recurrences before they received radiation therapy. Three patients were treated with irradiation alone, and 7 patients received surgery and irradiation (preoperatively in 1 patient and postoperatively in 6 patients). Eight patients had inverted papillomas (3 with concomitant squamous cell carcinoma), and 2 patients had cylindrical cell papillomas.

RESULTS

Local recurrence developed in 4 patients at 1.5, 6.5, 12, and 13 years after treatment. No evidence of recurrence was observed in 6 patients at 7, 8.5, 8.5, 9, 9, and 20.5 years after treatment. Four patients died of intercurrent disease. No patient developed a malignant transformation. Significant complications of treatment included, in 1 patient, an area of bone exposure in the orbit that necessitated debridement.

CONCLUSION

Surgery is the primary treatment of this entity. Radiation therapy should be considered in patients with incompletely resectable lesions, multiply recurrent tumors, and tumors associated with malignancy.

Association of inverted sinonasal papilloma with non-sinonasal head-and-neck carcinoma

The nature and pathogenesis of inverted papilloma of the nose and paranasal sinuses are debated. Evidence suggesting a viral association is controversial, and epidemiological evidence has pointed to tobacco smoking as a potential etiologic factor. A retrospective regional cohort of 197 patients with sinonasal papilloma was compared with a cohort of 1583 patients with nasal polyps showing a similar distribution by age and sex. All instances of head-and-neck carcinoma diagnosed in both cohorts during a 38-year calendar period were culled from the regional cancer registry, the incidence rate ratio was computed (papilloma:polyp, on tumors detected at the time of or prior to the index diagnosis), and the clinical details were obtained. Nine instances of oral or laryngeal squamous-cell carcinoma, all in men, were identified in the papilloma cohort, and 7 labial, oral or laryngeal carcinomas (2 in women) in patients with polyps. In addition, 5% of the papillomas progressed to sinonasal carcinoma, including 2 cases among those with other primary head-and-neck carcinomas. The incidence-rate ratio for non-sinonasal head-and-neck carcinoma was 12.8 (95% CI, 3. 7 to 50; p < 0.0001). Among the papilloma patients with oral/laryngeal carcinoma, 8 smoked tobacco. Inverted sinonasal papilloma is associated with an increase in non-sinonasal head-and-neck carcinoma, and tobacco may be a causative link.