The role of revision sinus surgery in the initiation of dupilumab therapy: A real-world study of molecular and cellular features.

KEY POINTS: A persistent type 2 endotype signature exists in recalcitrant chronic rhinosinusitis with nasal polyps mucosa on dupilumab. Revision sinus surgery immediately prior to dupilumab reduces long-term interleukin (IL)-4/IL-13 tissue mRNA. Pre-dupilumab revision surgery is associated with reduced tissue eosinophils and GATA-3+ cells.

Molecular patterns and mechanisms of tumorigenesis in HPV-associated and HPV-independent sinonasal squamous cell carcinoma.

Mechanisms of tumorigenesis in sinonasal squamous cell carcinoma (SNSCC) remain poorly described due to its rare nature. A subset of SNSCC are associated with the human papillomavirus (HPV); however, it is unknown whether HPV is a driver of HPV-associated SNSCC tumorigenesis or merely a neutral bystander. We hypothesized that performing the first large high-throughput sequencing study of SNSCC would reveal molecular mechanisms of tumorigenesis driving HPV-associated and HPV-independent SNSCC and identify targetable pathways. High-throughput sequencing was performed on 64 patients with HPV-associated and HPV-independent sinonasal carcinomas. Mutation annotation, viral integration, copy number, and pathway-based analyses were performed. Analysis of HPV-associated SNSCC revealed similar mutational patterns observed in HPV-associated cervical and head and neck squamous cell carcinoma, including lack of TP53 mutations and the presence of known hotspot mutations in PI3K and FGFR3. Further similarities included enrichment of APOBEC mutational signature, viral integration at known hotspot locations, and frequent mutations in epigenetic regulators. HPV-associated SNSCC-specific recurrent mutations were also identified including KMT2C , UBXN11 , AP3S1 , MT-ND4 , and MT-ND5 . Mutations in KMT2D and FGFR3 were associated with decreased overall survival. We developed the first known HPV-associated SNSCC cell line and combinatorial small molecule inhibition of YAP/TAZ and PI3K pathways synergistically inhibited tumor cell clonogenicity. In conclusion, HPV-associated SNSCC and HPV-independent SNSCC are driven by molecularly distinct mechanisms of tumorigenesis. Combinatorial blockade of YAP/TAZ and vertical inhibition of the PI3K pathway may be useful in targeting HPV-associated SNSCC whereas targeting MYC and horizontal inhibition of RAS/PI3K pathways for HPV-independent SNSCC. One Sentence Summary: This study solidifies HPV as a driver of HPV-associated SNSCC tumorigenesis, identifies molecular mechanisms distinguishing HPV-associated and HPV-independent SNSCC, and elucidates YAP/TAZ and PI3K blockade as key targets for HPV-associated SNSCC.

Biologics for Nasal Polyps: Synthesizing Current Recommendations into a Practical Clinical Algorithm.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) has been traditionally managed with a combination of topical and systemic medical therapy as well as endoscopic sinus surgery. The emergence of biologic therapies that target specific aspects of the inflammatory cascade has ushered in a potentially new paradigm in the management options available for CRSwNP. PURPOSE: To summarize the current literature and recommendations supporting the use of available biologic therapies for CRSwNP and to develop an algorithm to aid clinical decision-making regarding treatment selection. METHODS: A review of available literature and studies that demonstrated the clinical efficacy of biologic agents for the treatment of CRSwNP informing current CRSwNP consensus algorithms. RESULTS: Current biologic medications target immunoglobulin E, interleukins, or interleukin receptors implicated in the Th2 inflammatory cascade. Institution of biologic therapy is now an option for patients who have disease refractory to topical medical therapy and endoscopic sinus surgery, those who cannot tolerate surgery, or patients with other comorbid Th2 diseases. Response to treatment should be monitored at 4-6 months and 1 year after initiating therapy. Across multiple indirect comparisons, dupilumab appears to have the largest therapeutic benefit across multiple subjective and objective outcomes. The choice of therapeutic agent also depends on drug availability, patient tolerance, presence of comorbid illnesses, and cost. CONCLUSIONS: Biologics are emerging as an important option in the management of patients with CRSwNP. While more data is required to fully inform indications, treatment selection, and health economics related to their use, biologics may offer robust symptom relief to patients who have failed other interventions.

Olfaction Now and in the Future in CRSwNP.

BACKGROUND: Chronic rhinosinusitis (CRS) is the leading cause of olfactory dysfunction in the general population. Olfactory dysfunction is more common in patients with CRS with nasal polyposis (CRSwNP) compared to those without polyps. PURPOSE: The present review aims to summarize the current literature on the mechanism behind olfactory dysfunction in CRSwNP and the impact of therapy on olfactory outcomes in this patient population. METHODS: A comprehensive review of the available literature on olfaction in CRSwNP was performed. We evaluated the most recent evidence from studies on the mechanisms behind smell loss in CRSwNP and the impact of medical and surgical therapy for CRS on olfactory outcomes. RESULTS: The mechanism behind olfactory dysfunction in CRSwNP is not completely understood, but evidence from clinical research and animal models suggests both an obstructive component causing conductive olfactory loss and an inflammatory response in the olfactory cleft leading to sensorineural olfactory loss. Oral steroids and endoscopic sinus surgery have both shown efficacy in improving olfactory outcomes in CRSwNP in the short term; however, the long-term response of these treatments remains uncertain. Newer targeted biologic therapies, such as dupilumab, have also shown remarkable and durable improvement in smell loss for CRSwNP patients. CONCLUSION: Olfactory dysfunction is highly prevalent in the CRSwNP population. Although significant advances have been made in our understanding of olfactory dysfunction in the setting of CRS, additional studies are needed to elucidate cellular and molecular changes mediated by type 2-mediated inflammation in the olfactory epithelium with potential downstream effects on the central olfactory system. Further identification of these underlying basic mechanisms will be vital for developing future therapies targeted to improve olfactory dysfunction in patients with CRSwNP.

Chronic interleukin-13 expression in mouse olfactory mucosa results in regional aneuronal epithelium.

BACKGROUND: Olfactory dysfunction is highly associated with chronic rhinosinusitis with nasal polyps (CRSwNP), and the severity of loss has been linked with biomarkers of type 2 inflammation. The ability of dupilumab to rapidly improve the sense of smell prior to improvement in polyp size suggests a direct role of IL-4/IL-13 receptor signaling in the olfactory epithelium (OE). METHODS: We created a transgenic mouse model in which IL-13 is inducibly expressed specifically within the OE. Gene expression analysis and immunohistology were utilized to characterize the effect of IL-13 on the structure of the OE. RESULTS: After induction of olfactory IL-13 expression, there is a time-dependent loss of neurons from OE regions, accompanied by a modest inflammatory infiltrate. Horizontal basal cells undergo morphologic changes consistent with activation and demonstrate proliferation. Mucus production and increased expression of eotaxins is observed, with marked expression of Ym2 by sustentacular cells. DISCUSSION: Chronic IL-13 exposure has several effects on the OE that are likely to affect function. The neuronal loss is in keeping with other models of allergic type 2 nasal inflammation. Future studies are needed to correlate cellular and molecular alterations in olfactory cell populations with findings in human CRSwNP, as well as to assess olfactory function in behavioral model systems.

A bacterial extracellular vesicle-based intranasal vaccine against SARS-CoV-2 protects against disease and elicits neutralizing antibodies to wild-type and Delta variants.

Several vaccines have been introduced to combat the coronavirus infectious disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current SARS-CoV-2 vaccines include mRNA-containing lipid nanoparticles or adenoviral vectors that encode the SARS-CoV-2 Spike (S) protein of SARS-CoV-2, inactivated virus, or protein subunits. Despite growing success in worldwide vaccination efforts, additional capabilities may be needed in the future to address issues such as stability and storage requirements, need for vaccine boosters, desirability of different routes of administration, and emergence of SARS-CoV-2 variants such as the Delta variant. Here, we present a novel, well-characterized SARS-CoV-2 vaccine candidate based on extracellular vesicles (EVs) of Salmonella typhimurium that are decorated with the mammalian cell culture-derived Spike receptor-binding domain (RBD). RBD-conjugated outer membrane vesicles (RBD-OMVs) were used to immunize the golden Syrian hamster (Mesocricetus auratus) model of COVID-19. Intranasal immunization resulted in high titres of blood anti-RBD IgG as well as detectable mucosal responses. Neutralizing antibody activity against wild-type and Delta variants was evident in all vaccinated subjects. Upon challenge with live virus, hamsters immunized with RBD-OMV, but not animals immunized with unconjugated OMVs or a vehicle control, avoided body mass loss, had lower virus titres in bronchoalveolar lavage fluid, and experienced less severe lung pathology. Our results emphasize the value and versatility of OMV-based vaccine approaches.

A bacterial extracellular vesicle-based intranasal vaccine against SARS-CoV-2 protects against disease and elicits neutralizing antibodies to wild-type and Delta variants.

Several vaccines have been introduced to combat the coronavirus infectious disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current SARS-CoV-2 vaccines include mRNA-containing lipid nanoparticles or adenoviral vectors that encode the SARS-CoV-2 Spike (S) protein of SARS-CoV-2, inactivated virus, or protein subunits. Despite growing success in worldwide vaccination efforts, additional capabilities may be needed in the future to address issues such as stability and storage requirements, need for vaccine boosters, desirability of different routes of administration, and emergence of SARS-CoV-2 variants such as the Delta variant. Here, we present a novel, well-characterized SARS-CoV-2 vaccine candidate based on extracellular vesicles (EVs) of Salmonella typhimurium that are decorated with the mammalian cell culture-derived Spike receptor-binding domain (RBD). RBD-conjugated outer membrane vesicles (RBD-OMVs) were used to immunize the golden Syrian hamster ( Mesocricetus auratus ) model of COVID-19. Intranasal immunization resulted in high titers of blood anti-RBD IgG as well as detectable mucosal responses. Neutralizing antibody activity against wild-type and Delta variants was evident in all vaccinated subjects. Upon challenge with live virus, hamsters immunized with RBD-OMV, but not animals immunized with unconjugated OMVs or a vehicle control, avoided body mass loss, had lower virus titers in bronchoalveolar lavage fluid, and experienced less severe lung pathology. Our results emphasize the value and versatility of OMV-based vaccine approaches.

Taste receptors in chronic rhinosinusitus, what is the evidence? A systematic review.

BACKGROUND: Bitter and sweet taste receptors (T2Rs and T1Rs), respectively, are involved in the innate immune response of the sinonasal cavity and associated with chronic rhinosinusitis (CRS). Growing evidence suggests extraoral TRs as relevant biomarkers, but the current understanding is incomplete. This systematic review synthesizes current evidence of extraoral taste receptors in CRS. METHODS: PubMed, Embase, Cochrane, Web of Science, and Scopus were reviewed in accordance with Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines and included studies of genotypic and phenotypic T2R/T1R status in CRS patients. RESULTS: Twenty-two studies with 3845 patients were included. Seventeen studies evaluated genotype and 10 evaluated taste phenotypes. Four of 6 studies examining the haplotype distribution of the T2R, TAS2R38, demonstrated increased AVI/AVI haplotype ("nontaster") frequency in CRS. Meanwhile, 2 studies demonstrated decreased bitter sensitivity in CRS with nasal polyposis (CRSwNP), whereas 3 other studies reported decreased bitter sensitivity only in CRS without nasal polyposis (CRSsNP). Findings regarding sweet sensitivity were mixed. Three studies with cystic fibrosis patients (n = 1393) were included. Studies investigating the association between clinical outcomes and TAS2R38 alleles were limited, but the nonfunctional combination of AVI/AVI was associated with increased utilization of sinus surgery and, in CRSsNP patients, with poorer improvement of symptoms postoperatively. CONCLUSION: Both genotypic and phenotypic assessments of T2Rs suggest a potential association with CRS, particularly CRSsNP. However, limited evidence and mixed conclusions cloud the role of T2Rs in CRS. Future investigations should aim to increase diverse populations, broaden institutional diversity, examine T1Rs, and utilize uniform assessments.

Epigenetic regulation of epithelial dectin-1 through an IL-33-STAT3 axis in allergic disease.

Allergic diseases arise in susceptible individuals in part because of decrements in protective pathways. The mechanism by which these anti-inflammatory molecules become repressed remains unclear. We have previously reported that epithelial dectin-1 prevents aberrant type 2 responses and is downregulated in the epithelium of allergic patients. Here, we report that dectin-1 is constitutively expressed by the respiratory epithelium in humans and that IL-33 specifically acts as a repressor of dectin-1. Mechanistically, this occurs via IL-33-dependent STAT3 activation and the subsequent repression of the dectin-1 gene, CLEC7A. We have identified a novel enhancer region upstream of the proximal promoter of CLEC7A that is only accessible in epithelial cells, but not in hematopoietic cells. Epigenetic repression of CLEC7A through this newly identified locus, downstream of an aberrant IL-33-STAT3 axis, occurs in the epithelium of allergic individuals. Collectively, our data identify a mechanism of epigenetic fine-tuning of dectin-1 expression in epithelial cells that may participate in allergenicity.

Exposure to Particulate Matter Air Pollution and Anosmia.

Importance: Anosmia, the loss of the sense of smell, has profound implications for patient safety, well-being, and quality of life, and it is a predictor of patient frailty and mortality. Exposure to air pollution may be an olfactory insult that contributes to the development of anosmia. Objective: To investigate the association between long-term exposure to particulate matter (PM) with an aerodynamic diameter of no more than 2.5 µm (PM2.5) with anosmia. Design, Setting, and Participants: This case-control study examined individuals who presented from January 1, 2013, through December 31, 2016, at an academic medical center in Baltimore, Maryland. Case participants were diagnosed with anosmia by board-certified otolaryngologists. Control participants were selected using the nearest neighbor matching strategy for age, sex, race/ethnicity, and date of diagnosis. Data analysis was conducted from September 2020 to March 2021. Exposures: Ambient PM2.5 levels. Main Outcomes and Measures: Novel method to quantify ambient PM2.5 exposure levels in patients diagnosed with anosmia compared with matched control participants. Results: A total of 2690 patients were identified with a mean (SD) age of 55.3 (16.6) years. The case group included 538 patients with anosmia (20%), and the control group included 2152 matched control participants (80%). Most of the individuals in the case and control groups were women, White patients, had overweight (BMI 25 to <30), and did not smoke (women: 339 [63.0%] and 1355 [63.0%]; White patients: 318 [59.1%] and 1343 [62.4%]; had overweight: 179 [33.3%] and 653 [30.3%]; and did not smoke: 328 [61.0%] and 1248 [58.0%]). Mean (SD) exposure to PM2.5 was significantly higher in patients with anosmia compared with healthy control participants at 12-, 24-, 36-, 60-month time points: 10.2 (1.6) µg/m3 vs 9.9 (1.9) µg/m3; 10.5 (1.7) µg/m3 vs 10.2 (1.9) µg/m3; 10.8 (1.8) µg/m3 vs 10.4 (2.0) µg/m3; and 11.0 (1.8) µg/m3 vs 10.7 (2.1) µg/m3, respectively. There was an association between elevated PM2.5 exposure level and odds of anosmia in multivariate analyses that adjusted for age, sex, race/ethnicity, body mass index, alcohol or tobacco use, and medical comorbidities (12 mo: odds ratio [OR], 1.73; 95% CI, 1.28-2.33; 24 mo: OR, 1.72; 95% CI, 1.30-2.29; 36 mo: OR, 1.69; 95% CI, 1.30-2.19; and 60 mo: OR, 1.59; 95% CI, 1.22-2.08). The association between long-term exposure to PM2.5 and the odds of developing anosmia was nonlinear, as indicated by spline analysis. For example, for 12 months of exposure to PM2.5, the odds of developing anosmia at 6.0 µg/m3 was OR 0.79 (95% CI, 0.64-0.97); at 10.0 µg/m3, OR 1.42 (95% CI, 1.10-1.82); at 15.0 µg/m3, OR 2.03 (95% CI, 1.15-3.58). Conclusions and Relevance: In this study, long-term airborne exposure to PM2.5 was associated with anosmia. Ambient PM2.5 represents a potentially ubiquitous and modifiable risk factor for the loss of sense of smell.

Benralizumab effect on severe chronic rhinosinusitis with nasal polyps (CRSwNP): A randomized double-blind placebo-controlled trial.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) can be a severe and debilitating disease associated with significant morbidity, loss of smell, sinus pressure and asthma exacerbations. Eosinophils play a role in the majority (85%) of patients. Benralizumab, an afucosylated monoclonal antibody directed against the IL-5 receptor, has powerful apoptotic effects on eosinophils. OBJECTIVE: We sought to investigate the therapeutic benefit of inhibiting the IL-5 receptor using benralizumab to treat severe rhinosinusitis with nasal polyps. METHODS: Patients with severe NP (defined by endoscopic grade 5 or more out of 8) with elevated eosinophils and a history of previous surgical or endoscopic polypectomy met entry criteria and were randomized in a double-blind fashion to receive 30 mg benralizumab SC or placebo. Endoscopic NP score was assessed at baseline and at treatment week 20. CT scan, SNOT-22 survey and UPSIT smell test score changes were also evaluated. RESULTS: Thirty-three patients were screened, and twenty-four (n = 24) were enrolled in the study. Compared with baseline, benralizumab significantly improved NP score (-0.9 ± 0.2, P = 0.004) whereas placebo did not (-0.3 ± 0.3, P = 0.166). Benralizumab induced polyp size reduction compared with placebo did not reach statistical significance (P = 0.103). Five of 12 benralizumab-treated patients (42%) had improvements in all major outcomes (polyp score, CT, SNOT-22 and smell test) versus 2 out of 12 placebo (17%). The ratio of blood eosinophil count to allergen skin test positivity correlated with polyp reduction. CONCLUSION: Benralizumab was well-tolerated and compared with baseline achieved a statistically significant reduction in nasal polyp size, sinus occupancy, symptoms and improved sensation of smell for most patients (83%).

COVID-19 Vaccines May Not Prevent Nasal SARS-CoV-2 Infection and Asymptomatic Transmission.

Current COVID-19 vaccine candidates are administered by injection and designed to produce an IgG response, preventing viremia and the COVID-19 syndrome. However, systemic respiratory vaccines generally provide limited protection against viral replication and shedding within the airway, as this requires a local mucosal secretory IgA response. Indeed, preclinical studies of adenovirus and mRNA candidate vaccines demonstrated persistent virus in nasal swabs despite preventing COVID-19. This suggests that systemically vaccinated patients, while asymptomatic, may still be become infected and transmit live virus from the upper airway. COVID-19 is known to spread through respiratory droplets and aerosols. Furthermore, significant evidence has shown that many clinic and surgical endonasal procedures are aerosol generating. Until further knowledge is acquired regarding mucosal immunity following systemic vaccination, otolaryngology providers should maintain precautions against viral transmission to protect the proportion of persistently vulnerable patients who exhibit subtotal vaccine efficacy or waning immunity or who defer vaccination.

Interleukin 13 (IL-13) alters hypoxia-associated genes and upregulates CD73.

BACKGROUND: Interleukin 13 (IL-13) is a pleiotropic cytokine that has been shown to be important in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) and other type 2 inflammation-related diseases. Increased IL-13 expression can elicit several pro-inflammatory effects, including eosinophilia, and pathology such as increased mucus secretion. Polypogenesis in chronic rhinosinusitis (CRS) can be caused by hypoxia, which can also lead to hyperpermeability of airway epithelium and epithelium-to-mesenchymal translation through the upregulation of hypoxia-associated genes, such as HIF1. Whether T-helper 2 (Th2) inflammatory cytokines, such as IL-13, can also induce sinonasal epithelial hypoxia-associated genes is currently unknown. METHODS: Human air-liquid interface (ALI) sinonasal epithelial cell cultures treated with recombinant IL-13 were analyzed by real-time polymerase chain reaction (PCR) and flow cytometry to determine the effect on epithelial cells. RESULTS: Whole tissue from CRSwNP subjects showed increased HIF1A gene expression. Treatment of fully differentiated human ALI cultures with IL-13 resulted in a concurrent increase in HIF1A and ARNT messenger RNA (mRNA) expression. However, the level of EPAS1 expression was significantly reduced. IL-13 also had a dose-dependent response on the expression of HIF genes and the time course experiment showed peak expression of HIF1A and ARNT at 5 to 7 days poststimulation. Remarkably, CD73 surface expression also peaked at day 5 poststimulation. CONCLUSION: Our data suggests that IL-13 can induce hypoxia signaling pathway genes leading to surface expression of CD73, which has an anti-inflammatory effect.

Serum amyloid A is a soluble pattern recognition receptor that drives type 2 immunity.

The molecular basis for the propensity of a small number of environmental proteins to provoke allergic responses is largely unknown. Herein, we report that mite group 13 allergens of the fatty acid-binding protein (FABP) family are sensed by an evolutionarily conserved acute-phase protein, serum amyloid A1 (SAA1), that promotes pulmonary type 2 immunity. Mechanistically, SAA1 interacted directly with allergenic mite FABPs (Der p 13 and Blo t 13). The interaction between mite FABPs and SAA1 activated the SAA1-binding receptor, formyl peptide receptor 2 (FPR2), which drove the epithelial release of the type-2-promoting cytokine interleukin (IL)-33 in a SAA1-dependent manner. Importantly, the SAA1-FPR2-IL-33 axis was upregulated in nasal epithelial cells from patients with chronic rhinosinusitis. These findings identify an unrecognized role for SAA1 as a soluble pattern recognition receptor for conserved FABPs found in common mite allergens that initiate type 2 immunity at mucosal surfaces.

Dexpramipexole depletes blood and tissue eosinophils in nasal polyps with no change in polyp size.

OBJECTIVE: Chronic rhinosinusitis with nasal polyps (CRSwNP) and eosinophilia is a disease of the upper respiratory tract for which few therapies are available. Because the oral investigational drug dexpramipexole serendipitously decreased blood eosinophils in amyotrophic lateral sclerosis studies, we assessed its safety, eosinophil-lowering activity, and preliminary clinical efficacy in patients with CRSwNP and eosinophilia. METHODS: Sixteen subjects with CRSwNP, absolute eosinophil count (AEC) ≥ 0.300 × 109 /L, and polyp tissue eosinophils were evaluable for efficacy in a 6-month open-label, multi-center study of dexpramipexole 150 mg twice daily. The coprimary endpoints were change in AEC and change in total polyp score (TPS) from baseline to month 6, with additional clinical and histologic endpoints assessed. RESULTS: Thirteen of 16 subjects completed 6 months of dexpramipexole treatment. Geometric mean baseline AEC was 0.525 ± 0.465 eosinophils × 109 /L and decreased to 0.031 ± 0.019 after 6 months of dexpramipexole treatment, a 94% reduction (P < 0.001). Ten of 16 subjects had eosinophil counts reduced to ≤ 0.020 × 109 /L at month 6. In 12 subjects with nasal polyp biopsies at baseline and month 6, tissue eosinophils were reduced from a mean of 168 ± 134 to 5 ± 2 per high-power field (HPF) (P = 0.001), a 97% reduction from baseline. There was no significant reduction in TPS or improvement in other clinical endpoints. Dexpramipexole was well tolerated, with no drug-related serious adverse events. CONCLUSION: Dexpramipexole treatment produced profound eosinophil-lowering in peripheral blood and nasal polyp tissue. Despite the near-elimination of polyp eosinophils, decreased TPS and nasal symptom improvement were not observed. LEVEL OF EVIDENCE: 2 Laryngoscope, 129:E61-E66, 2019.

Endonasal endoscopic resection of olfactory neuroblastoma: an 11-year experience.

OBJECTIVE: Olfactory neuroblastoma (ONB) is a rare malignant neoplasm of the sinonasal cavity. Surgery has been and remains a mainstay of treatment for patients with this tumor. Open craniofacial resections have been the treatment of choice for many decades. More recently, experience has been growing with endoscopic approaches in the management of patients with ONB. The object of this study is to report the authors' experience over the past 11 years with ONB patients treated with purely endonasal endoscopic techniques. METHODS: The authors performed a retrospective chart review of 20 consecutive patients with ONB who underwent a completely endonasal endoscopic approach for an oncological tumor resection at their institution between January 2006 and January 2017. Patient demographics, tumor stage, pathological grade, frozen section analysis, permanent margin assessment, perioperative complications, postoperative therapy, length of follow-up, and outcomes at last follow-up were collected and analyzed. RESULTS: Eighteen patients presented with newly diagnosed disease, with a modified Kadish stage of A in 2 cases, B in 3, C in 11, and D in 2. Two patients presented with recurrent tumors. An average of 25.3 specimens per patient were examined by frozen section analysis. Although analysis of intraoperative frozen section margins was negative in all but 1 case, microscopic foci of tumor were found in 7 cases (35%) on permanent histopathological analysis. Perioperative complications occurred in 7 patients (35%) including 1 patient who developed a cerebrospinal fluid leak; there were no episodes of meningitis. All but 1 patient received postoperative radiotherapy, and 5 patients received postoperative chemotherapy. With a mean follow-up of over 5 years, 19 patients were alive and 1 patient died from an unrelated cause. There were 2 cases of tumor recurrence. The 5-year overall, disease-specific, and recurrence-free survival rates were 92.9%, 100%, and 92.9%, respectively. CONCLUSIONS: The current results provide additional evidence for the continued use of endoscopic procedures in the management of this malignancy.