Facial Surface Electromyography: A Novel Approach to Facial Nerve Functional Evaluation after Vestibular Schwannoma Surgery.

BACKGROUND: Vestibular schwannoma (VS) surgery may cause facial nerve damage. However, a comprehensive evaluation of post-operative facial outcomes may be difficult to achieve. Surface electromyography (sEMG) is a promising non-invasive evaluation tool. However, its use in the follow-up after VS surgery has not been reported yet. The main objective was to develop and validate a new sEMG application specifically for the post-VS surgery setting. Secondary goals were to provide a systematic description of facial muscle activity after VS surgery and assess the association between sEMG parameters and Sunnybrook scale scores. METHODS: Thirty-three patients with facial palsy following VS surgery were included. The clinical outcomes (Sunnybrook symmetry, movement, and synkinesis scores) and sEMG parameters (signal amplitude normalized by the maximal voluntary contraction (NEMG) and sEMG synkinesis score (ESS, number of synkinesis per movement sequence)) were evaluated at the end of the follow-up. RESULTS: In all tested muscles, NEMG variance was significantly higher on the affected side than the contralateral (variance ratio test, p < 0.00001 for each muscle). In total, 30 out of 33 patients (90.9%) showed an ESS ≥ 1 (median: 2.5, IQR: 1.5-3.0). On the affected side, NEMG values positively correlated with both dynamic and overall Sunnybrook scores (Spearman's model, p < 0.05 for each muscle, except orbicularis oculi). ESS significantly correlated with the Sunnybrook synkinesis score (Spearman's rho: 0.8268, p < 0.0001). CONCLUSIONS: We described and preliminarily validated a novel multiparametric sEMG approach based on both signal amplitude and synkinesis evaluation specifically for oto-neurosurgery. Large-scale studies are mandatory to further characterize the semiological and prognostic value of facial sEMG.

Facial surface electromyography: A systematic review on the state of the art and current perspectives.

PURPOSE: Peripheral facial nerve palsy is a severely disabling condition. In current clinical practice, the commonest tools to assess facial palsy are grading scales, digital face image analyses or facial muscle electrophysiology. However, these techniques suffer from subjectivity or invasiveness and cannot be applied as part of a routine clinical assessment. Therefore, novel non-invasive office-based tools are needed. Surface electromyography (sEMG) may potentially fulfill the requirements of objectivity, low examiner-dependence, and minimal invasiveness. The aim of this systematic review is to define the state of the art on the use of sEMG for facial nerve functional assessment. MATERIALS AND METHODS: Pubmed, Scopus and Web of Science databases were systematically searched. The study protocol was registered on PROSPERO in January 2023. The review was conducted according to the PRISMA guidelines. RESULTS: After the application of inclusion-exclusion criteria, 15 manuscripts with adequate relevance to this topic were included in the review. CONCLUSIONS: Facial sEMG represents a potentially useful tool to implement objective quantification of facial nerve function in clinical practice. Given the heterogeneity of methods and analysis in the available studies, sEMG results are hardly comparable. The introduction of methodological guidelines, followed by large prospective studies on well-defined subsets of patients with facial nerve impairment, is advocated.

Prognostic Factors for Hearing Preservation Surgery in Small Vestibular Schwannoma.

OBJECTIVE: to evaluate recent contributions to the literature on prognostic factors of hearing preservation in small vestibular schwannoma microsurgery. METHODS: review of the most recent studies. RESULTS: factors such as tumor size, preoperative hearing status, tumor growth rate, tumor origin, surgical approach, radiological characteristics, results of preoperative neurophysiological tests, preoperative symptoms and demographic features have been investigated and some of them reported to be significant in the prediction of hearing preservation. CONCLUSIONS: tumor size and preoperative hearing status are the most impactful factors and play a key role in patient selection for hearing preservation surgery. Other features such as fundal extension, tumor origin and impaired ABR could have prognostic value on hearing preservation. Tumor growth rate, preoperative impedance, cVEMPs and age have also recently been found to be significant, but more studies are needed. The role of preoperative tinnitus, vertigo and gender is lacking and controversial, whereas the differences between available surgical approaches have been smoothed out in recent years.

Intraoperative Cochlear Nerve Monitoring in Cochlear Implantation after Vestibular Schwannoma Resection.

BACKGROUND: The use of a cochlear implant (CI) for hearing rehabilitation after vestibular schwannoma (VS) resection is widely spreading. The procedure is usually performed simultaneously to tumor resection with a translabyrinthine approach. To ensure the best device function, assessing the integrity of the cochlear nerve is of primary importance. METHODS: A narrative review of the literature on the present topic was carried out up to June 2022. Finally, nine studies were considered. RESULTS: Electrically evoked auditory brainstem responses (eABR) is the most widely used method of intraoperative monitoring of cochlear nerve (CN) during VS resection, although its limits are known. It can be assessed through the CI electrode array or through an intracochlear test electrode (ITE). Variations of the graph are evaluated during the surgical procedure, in particular the wave V amplitude and latency. As tumor dissection progresses, the parameters may change, informing of the CN status, and the surgical procedure may be modulated. CONCLUSION: An eABR positive result seems to be reliably correlated with a good CI outcome in those cases in which a clear wave V is recorded before and after tumor removal. On the contrary, in those cases in which the eABR is lost or altered during the surgical procedure, the positioning of a CI is still debatable.

Tumor Microenvironment in Sporadic Vestibular Schwannoma: A Systematic, Narrative Review.

Although diagnosis and treatment of vestibular schwannomas (VSs) improved in recent years, no factors have yet been identified as being capable of predicting tumor growth. Molecular rearrangements occur in neoplasms before any macroscopic morphological changes become visible, and the former are the underlying cause of disease behavior. Tumor microenvironment (TME) encompasses cellular and non-cellular elements interacting together, resulting in a complex and dynamic key of tumorigenesis, drug response, and treatment outcome. The aim of this systematic, narrative review was to assess the level of knowledge on TME implicated in the biology, behavior, and prognosis of sporadic VSs. A search (updated to November 2022) was run in Scopus, PubMed, and Web of Science electronic databases according to the PRISMA guidelines, retrieving 624 titles. After full-text evaluation and application of inclusion/exclusion criteria, 37 articles were included. VS microenvironment is determined by the interplay of a dynamic ecosystem of stromal and immune cells which produce and remodel extracellular matrix, vascular networks, and promote tumor growth. However, evidence is still conflicting. Further studies will enhance our understanding of VS biology by investigating TME-related biomarkers able to predict tumor growth and recognize immunological and molecular factors that could be potential therapeutic targets for medical treatment.

Survival Outcomes in Squamous Cell Carcinoma of the External Auditory Canal: A Systematic Review and Meta-Analysis.

Squamous cell carcinomas (SCC) of the external auditory canal (EAC) are rare tumors representing a surgical challenge. Current knowledge is based largely on case series; thus, the level of evidence is weak. This study sought to systematically review the available SCC of the EAC literature and to identify risk factors for overall survival (OS) and disease-specific survival (DSS). A systematic review and meta-analysis of papers searched up to December 2022 through PubMed, Scopus, Web of Science, and Cochrane Library databases was conducted. Quality assessment of the eligible studies was done according to the Newcastle-Ottawa Scale. Pooled univariate and multivariable analyses and meta-analysis using a random-effects or fixed-effects Mantel-Haenszel model were performed. Fifteen articles (282 patients) met the inclusion criteria and were included in the quantitative analysis. The pooled multivariable analysis revealed cT3 and cT4 as independent prognostic factors for OS (p = 0.005, and p < 0.001, respectively) and DSS (p = 0.002, and p < 0.001, respectively). Local recurrence rate was 32.3%. The meta-analysis estimated significantly higher odds ratios for advanced T categories, than cT1-T2 tumors for OS and DSS (OR = 3.55; 95% CI, 1.93-6.52, and OR = 3.73; 95% CI, 2.00-6.97, respectively). In conclusion, locally advanced tumors were associated with poor prognosis. Poor outcomes mostly occurred due to local recurrence.

Intra-Operative Cochlear Nerve Function Monitoring in Hearing Preservation Surgery: A Systematic Review of the Literature.

With the recent scientific and technical developments, hearing preservation surgery is becoming a growing objective in inner ear pathologies, especially for vestibular schwannomas. In this review, we aim to describe the pros and cons of the following cochlear nerve monitoring techniques: ABRs (auditory brainstem responses), DENM (direct eighth cranial nerve monitoring), EcochG (electrocochleography), CNAP (cochlear compound nerve action potentials), DPOAE (distortion product otoacoustic emissions), PAMRs (postauricular muscle responses). The Cochrane library, Scopus, DynaMed, and PubMed databases were screened to obtain any relevant papers from October 2009 to the present day. Due to the heterogeneity of the existing studies in the literature, there is no way to tell whether a technique is better than another. All authors reported satisfactory outcomes with the cochlear nerve monitoring techniques tested, either alone or in combination.

Early surgery and definitive cure in small sporadic vestibular schwannoma.

Objective: To report surgical outcomes of a cohort of small sporadic vestibular schwannoma and discuss the role of early surgery. Methods: Retrospective descriptive analysis of 234 consecutive patients with small vestibular schwannoma operated on with translabyrinthine or hearing preservation surgical approaches. Outcome measures were control of disease, postoperative facial nerve function, complications and hearing outcome. Results: A translabyrinthine approach was performed in 59% of cases, hearing preservation surgery in 40% and transmeatal approach in 1%, respectively. Complete resection was achieved in 100% of cases. Overall, postoperative major and minor complications were 8.5% in the series, with complete recovery and no sequalae. Facial nerve function at one year postoperatively was House-Brackmann scale (HB) 1-2 in 95% of cases. The rate of hearing preservation was 70% A-B-C classes of Tokyo classification and 77% AB classes of AAOHNS classification. Conclusions: Early surgery in small vestibular schwannoma is a valid option, due to good functional outcomes, low morbidity and definitive cure. Early surgery is associated with better outcomes when considered in relation to non-surgical treatments reported in the literature.

Cochlear implant in vestibular schwannomas: long-term outcomes and critical analysis of indications.

PURPOSE: To describe our institutional experience in cochlear implantation after vestibular schwannoma (VS) resection, and compare the audiological outcomes between sporadic and neurofibromatosis type 2 (NF2) VS sub-cohorts of patients, and in relation to preoperative contralateral hearing. METHODS: Seventeen patients (8 sporadic and 9 NF2-associated VSs) who had undergone VS resection and cochlear implant (CI) were analyzed retrospectively. Audiological outcomes at 24 months were correlated with preoperative clinical variables. The results according to VS type (sporadic vs. NF2-associated) and contralateral hearing (impaired vs. normal) were compared. RESULTS: Fourteen CIs were actively used by the patients (77.8%). Twenty-four months after CI activation, the median postoperative PTA (pure tone average) was 45.6 dB nHL and a measurable WRS (Word Recognition Score) was achieved by 44.4% of patients (median WRS = 40%). The median postoperative PTA in the implanted ear resulted better in the group with an impaired contralateral hearing (36.3 dB nHL vs. 78.8 dB nHL, p = 0.019). Good preoperative contralateral hearing status (A-B classes of AAO-HNS) was a negative prognostic factor for CI performance on open-set discrimination (OR = 28.0, 95% CI 2.07-379.25, p = 0.012). CONCLUSIONS: CI is a viable rehabilitative option for patients with sporadic or NF2-associated VS. A good contralateral hearing adversely affects CI outcome and should be taken into consideration for patients' selection and rehabilitation programs.

Resection of the internal carotid artery in selected patients affected by cancer of the skull base.

Invasion of the internal carotid artery (ICA) has been historically considered a criterion of non-resectability of skull base cancer (SBC). Patients affected by SBC who underwent surgery including resection of ICA at two tertiary institutions were included. Demographics, oncologic, and surgical information, complications, and survival outcomes were retrospectively reviewed. Survival outcomes were calculated. Ten patients were included. Three surgical approaches (transnasal endoscopic, transorbital, and transpetrosal) were employed to resect the invaded/abutted tract(s) of the ICA. All patients underwent ICA temporary balloon occlusion test. In two patients, an extracranial-to-intracranial arterial bypass was harvested. Major neuromorbidity was observed in two patients. Perioperative mortality of the series was 10.0%. Mean overall survival was 27.2 months, with 2-year overall and progression-free survival rate of 88.9%. ICA resection is feasible as part of the ablation performed for very advanced SBCs. Survival outcomes are acceptable in adequately selected patients.

Tumor budding to investigate local invasion, metastasis and prognosis in temporal bone squamous cell carcinoma.

BACKGROUND: Few studies have tried to go beyond the conventional clinic-pathological prognostic factors investigating the molecular markers involved in the biology of temporal bone squamous cell carcinoma (TBSSC). Tumor budding represents a very aggressive subpopulation of cancer cells and demonstrates the heterogeneity of cancer cells residing in different locations within tumors. The main aim of this exploratory study was to investigate the role of tumor budding in primary TBSCC prognosis. We also analyzed the association between TBSCC tumor budding and: (i) loco-regional aggressiveness evaluated according to the revised Pittsburgh staging system, (ii) tumor infiltrating lymphocytes, lymphovascular invasion (LVSI), perineural invasion, pattern of invasion, and type of stroma. METHODS: Thirty-two TBSCCs treated surgically were considered. The three-tier grading system recommended by the International Tumor Budding Consensus Conference was used first on TBSCC. RESULTS: Advanced (T3-4) TBSCC was related with high risk intra-tumoral budding (ITB) at two-tier risk grading (p = 0.0361). N + status was associated with intermediate/high budding (Bd2-3) at three-tier risk grading for peri-tumoral budding (PTB) (p = 0.0382). Disease-free survival (DFS) was related with T-stage (p = 0.0406), N-status (p < 0.0001), PTB two-tier risk grading (p = 0.0463), LVSI (p < 0.0001). Overall survival (OS) was associated with N-status (p = 0.0167), PTB absolute count (p = 0.0341), PTB three-tier risk grading (p = 0.0359), PTB two-tier risk grading (p = 0.0132), and LVSI (p = 0.0004). At the multivariate analysis, DFS was related with N-status (p = 0.0147) and LVSI (p < 0.0001), while OS resulted associated only with LVSI (p = 0.0144). CONCLUSIONS: Our preliminary findings suggest that tumor budding in TBSCC, regardless of its localization (the main tumor body [ITB] or invasive front [PTB]) may be a reliable predictor of neck lymph node metastasis and poor prognosis. Tumor budding and LVI could be predictive markers for precise treatment in TBSCC. Further investigations on larger prospective series should be designed to confirm this evidence both in post-operative specimens and in preoperative biopsies.

Nasal polyps in eosinophilic granulomatosis with polyangiitis: Structured histopathology and CD105 expression.

PURPOSE: Distinguishing the prodromal nasal polyposis of eosinophilic granulomatosis with polyangiitis (EGPA) from chronic rhinosinusitis with nasal polyps (CRSwNP) is a challenge for rhinologists and rheumatologists. It has recently been reported that angiogenesis and CD105 expressed on vascular endothelial cells could have a role in the pathogenesis and development of nasal polyps. This exploratory study examined the structured histopathology of nasal polyps in patients with EGPA and CRSwNP, comparing CD105 expression in their nasal tissue with that of a control group with no chronic sinonasal inflammation. METHODS: A structured histopathological study was performed on surgical specimens of nasal tissue from 32 adults (13 with EGPA, 14 with CRSwNP, 5 controls), considering CD105 as a marker to determine microvessel density (MVD). RESULTS: The mean eosinophil count was higher in EGPA patients with tissue inflammation (p = .002), and in CRSwNP patients with sub-epithelial edema (p = .009). Neutrophil infiltration was significantly associated with severe tissue inflammation in EGPA patients (p = .04), but with the absence of fibrosis in CRSwNP patients (p = .04). In the EGPA group, CD105-MVD correlated with tissue eosinophil count (p = .05). Mean CD105-MVD was significantly higher in EGPA patients with mucosal ulceration (p = .004). In the CRSwNP group, a CD105-MVD correlated positively and significantly with tissue eosinophil count (p = .01). CONCLUSION: Alongside the known abundance of eosinophils, other cells might contribute to inflammatory processes. Neutrophils may amplify inflammation, eosinophil recruitment and tissue damage. CD105 expression in CRSwNP and EGPA nasal polyps supports the hypothesized involvement of angiogenesis in the pathogenesis and development of nasal polyps.

Prognostic Significance of CD105- and CD31-Assessed Microvessel Density in Paired Biopsies and Surgical Samples of Laryngeal Carcinoma.

Small pretreatment laryngeal biopsies may not fully represent a tumor's biological profile. This study on laryngeal squamous cell carcinoma (LSCC) aimed to investigate the prognostic role of CD105- and CD31-assessed microvessel density (MVD) in paired biopsies and surgical specimens and the association and discrepancy between CD105- and CD31-assessed MVD in biopsies and surgical specimens. CD105- and CD31-assessed MVD was analyzed in paired biopsies and surgical specimens of 45 consecutive cases of LSCC. In the LSCC biopsies and surgical specimens, median CD105-assessed MVD was significantly higher in N+ than in N0 cases (p = 0.0008, and p = 0.0002, respectively). Disease-free survival (DFS) was associated with CD105- and CD31-assessed MVD in both biopsies and surgical specimens (p < 0.0001 for all specimens). Multivariable Cox's regression showed that pathological grade (p < 0.0001) and CD105-assessed MVD in LSCC biopsies (p = 0.0209) predicted DFS. Lin's concordance coefficient showed that CD31 overestimated MVD compared with CD105 in LSCC biopsies and surgical specimens. CD105-assessed MVD should be further investigated in larger LSCC series as a potential prognostic marker for identifying: patients at higher risk of recurrence who might warrant more aggressive therapy; and cN0 patients requiring elective neck dissection for a significant risk of regional metastasis.

Road traffic whiplash injury in the elderly: Clinical and video-nystagmographic features.

PURPOSE: Whiplash is a type of trauma typically caused by a rear end collision in a road accident. About one in two patients who experience whiplash report dizziness and balance problems, which can severely affect their activities in daily life. In industrialized countries, the number of elderly people with a driving license has increased in recent years. The aims of the present study were to describe the video-nystagmographic features in a consecutive series of elderly patients experiencing whiplash injury in a road accident, comparing them with similar injuries in a group of young adults. METHODS: Twenty-seven patients aged 65 years or more and a control group of 32 young adults between 18 and 21 years old were retrospectively selected. All patients underwent oto-vestibular assessment and video-nystagmography. RESULTS: After whiplash trauma, vertigo was more common in elderly patients with decreased peak velocity during the saccadic ocular motricity test (p = 0.017) and with evidence of bilateral vestibular hypofunction after caloric stimulation (p = 0.033). Comparing the two age groups, neck pain after the trauma was reported significantly more by young adults (p = 0.003), who also showed more frequently bilateral vestibular hypofunction (p = 0.025). CONCLUSION: Clinical and instrumental findings seem to support the hypothesis of a functional lesion to the brainstem regions after a whiplash injury. There is an undeniable need, however, for tools capable of objectively assessing the functional or anatomical damage resulting from whiplash-associated disorders, for both clinical and medico-legal reasons.

Biological tumor markers (maspin, CD105, nm23-H1) and disease relapse in laryngeal cancer: cluster analysis.

BACKGROUND: The aim of this investigation was to see if a panel of biomarkers (maspin, CD105, and nm23-H1) could be used to stratify patients with laryngeal squamous cell carcinoma (LSCC) in homogeneous disease recurrence risk clusters. METHODS: Cluster analysis was used to classify 89 patients based on their immunohistochemical expression of nm23-H1, CD105, and maspin. RESULTS: Our analysis identified seven homogeneous clusters: the LSCC recurrence rate was lowest in cluster 6 (non-nuclear maspin pattern, nuclear nm23-H1 expression ≥10%, endothelial CD105 expression <6%; P = .009), and highest in cluster 3 (non-nuclear maspin pattern, nuclear nm23-H1 expression <10%, endothelial CD105 expression ≥6%; P <.001). CONCLUSIONS: Similar panels of biological variables identified by cluster analysis should be tested in prospective clinical trials to establish whether treating patients identified as being at higher risk of LSCC recurrence more aggressively could significantly improve their recurrence rate and/or disease-specific survival.

A classification of chronic rhinosinusitis with nasal polyps based on structured histopathology.

AIMS: In chronic rhinosinusitis with nasal polyps (CRSwNP), tools based on objective evidence, such as histopathology, are needed to assist clinical decision-making. The main aim of this exploratory investigation was to determine whether structured histopathology could be used to classify CRSwNP in homogeneous histological clusters. METHODS AND RESULTS: A cohort of 135 CRSwNP patients was assessed, on the basis of clinicopathological features: allergic fungal rhinosinusitis (17 patients); non-steroidal anti-inflammatory drug-exacerbated respiratory disease (19 patients); intrinsic asthma (18 patients); extrinsic asthma (21 patients); allergy (21 patients); histologically eosinophilic (22 patients); and histologically non-eosinophilic (17 patients). For structured histopathology, we considered: the degree of inflammation; eosinophil count; eosinophil aggregates; neutrophil infiltration; goblet cell hyperplasia; basement membrane thickening; fibrosis; hyperplastic/papillary changes; squamous metaplasia; mucosal ulceration; and subepithelial oedema. Cluster analysis identified four distinct sets of cases. On discriminant analysis, the global error rate was 1.48%, and the stratified error rates were 4.34%, 0%, 0%, and 0% for clusters 1, 2, 3 and 4, respectively. Cluster 1 was characterised by infrequent fibrosis (<4.5% of cases). Cluster 2 mainly featured neutrophil infiltration in 100% of cases, hyperplastic/papillary changes in 70% of cases, and fibrosis in 65% of cases. Cluster 3 showed fibrosis in 100% of cases. Cluster 4 showed hyperplastic/papillary changes in 100% of cases, and fibrosis in 92% of cases. CONCLUSIONS: This study shows that cluster analysis can identify different histotypes among CRSwNP patients. The next step will be to investigate, in a larger series, the clinical (e.g. prognostic) implications of identifying such homogeneous clusters of patients with CRSwNP on the basis of their structured histopathology.

Cochlear-Vestibular Impairment due to West Nile Virus Infection.

OBJECTIVES: West Nile virus (WNV) has been spreading over the last 20 years. Human infection is asymptomatic in most cases. When the disease becomes clinically manifest, it may involve a range of issues, from a mild infection with flu-like symptoms to a neuroinvasive disease. Albeit rarely, WNV-associated sensorineural hearing loss (SNHL) has also been reported. Here we describe two new cases of SNHL and balance impairment caused by WNV infection. METHODS: The patients were investigated with repeated audiometric tests and, for the first time, videonystagmography was also used. RESULTS: Unlike findings in the few other published cases, an improvement in audiometric thresholds and vestibular function was documented in both of our patients. CONCLUSIONS: In the light of our findings, a prospective study would be warranted on a large series of patients with WNV infection in order: (i) to better define the epidemiology of the related cochlear-vestibular involvement; and (ii) to elucidate the virus-related changes to peripheral and central auditory and vestibular functions.

Histopathological and hematological changes in recurrent nasal polyposis.

BACKGROUND: There is a dearth of information regarding the histological and hematological differences between primary and recurrent chronic rhinosinusitis with nasal polyps (CRSwNP). The present study analyzed the histological changes in recurrent CRSwNP in terms of eosinophilic infiltrate, subepithelial edema, goblet cell hyperplasia, and basement membrane thickness. Blood levels of eosinophils and basophils were also measured prior to surgery on both primary and recurrent disease. METHODS: Thirty-two consecutive adult patients with nasal polyposis treated with primary surgery who subsequently underwent revision surgery were retrospectively enrolled. RESULTS: At primary surgery, a significant positive correlation (all p < 0.05) emerged between all histopathological parameters, and between tissue eosinophil and blood eosinophil counts. A positive correlation between subepithelial edema scores and blood basophil levels (p < 0.025) also came to light. At revision surgery, only basement membrane thickness correlated positively with: (1) tissue eosinophil count; and (2) goblet cell hyperplasia (both p = 0.001). In recurrent disease, there was again a positive correlation between eosinophil counts in tissue and blood (p < 0.05). The mean tissue eosinophil count in recurrent CRSwNP was significantly lower than in the primary disease (p < 0.001). CONCLUSION: Our preliminary results support the hypothesis that tissue remodeling due to surgical and medical treatments for CRSwNP is a dynamic process involving important differences in tissue eosinophil counts between primary and recurrent CRSwNP. How tissue remodeling evolves after CRSwNP treatment warrants further investigation, not only in larger series of patients, but also after stratifying patients by the time elapsing since their treatment.

Non-Eosinophilic Chronic Rhinosinusitis With Nasal Polyps: Eosinophil, Basophil, and Neutrophil Blood Counts Before and After Surgery.

OBJECTIVES: Research selectively investigating non-eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) is lacking. The inflammatory patterns seen in non-eosinophilic CRSwNP are still poorly understood. The present study is the first to compare blood eosinophil, basophil, and neutrophil counts before/after surgery in patients with non-eosinophilic CRSwNP stratified by their clinical features. METHODS: The study concerned 107 consecutive patients with histologically confirmed non-eosinophilic CRSwNP who underwent endoscopic sinus surgery (ESS). RESULTS: Statistical analysis ruled out any significant change in mean blood eosinophil, basophil, and neutrophil counts after ESS. A significant positive correlation emerged between blood eosinophil and basophil counts in both pre- and post-ESS laboratory tests. In the subcohort of allergic patients, a significant negative correlation was found after ESS between eosinophil and neutrophil levels and between basophil and neutrophil levels. CONCLUSIONS: In eosinophilic CRSwNP, ESS can clear polyps, remove inflammatory tissue, and reduce the inflammatory cytokines it generates, with a consequent reduction in blood eosinophil levels. The different results in non-eosinophilic CRSwNP support the conviction that the 2 types of CRSwNP are entities with distinct inflammatory response patterns.