Clinical value of office-based endoscopic incisional biopsy in diagnosis of nasal cavity masses

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Multiparametric MRI-based radiomics nomogram for predicting malignant transformation of sinonasal inverted papilloma

AIM

To investigate the feasibility of a radiomics nomogram model for predicting malignant transformation in sinonasal inverted papilloma (IP) based on radiomic signature and clinical risk factors.

MATERIALS AND METHODS

This single institutional retrospective review included a total of 143 patients with IP and 75 patients with IP with malignant transformation to squamous cell carcinoma (IP-SCC). All patients underwent surgical pathology and had preoperative magnetic resonance imaging (MRI) and computed tomography (CT) sinus studies between June 2014 and February 2022. Radiomics features were extracted from contrast-enhanced T1-weighted images (CE-T1WI), T2-weighted images (T2WI), and apparent diffusion coefficient (ADC) maps. The least absolute shrinkage and selection operator (LASSO) were performed to select the features extracted from the sequences mentioned above. Independent clinical risk factors were identified by multivariate logistic regression analysis. Radiomics nomogram was constructed by incorporating independent clinical risk factors and radiomics signature. Based on discrimination and calibration, the diagnostic performance of the nomogram was evaluated.

RESULTS

Twelve radiomics features were selected to develop the radiomics model with an area under the curve (AUC) of 0.987 and 0.989, respectively. Epistaxis (p=0.011), T2 equal signal (p=0.003), extranasal invasion (p<0.001), and loss of convoluted cerebriform pattern (p=0.002) were identified as independent clinical predictors. The radiomics nomogram model showed excellent calibration and discrimination (AUC: 0.993, 95% confidence interval [CI]: 0.985-1.00 and 0.990, 95% CI: 0.974-1.00) in the training and validation sets, respectively.

CONCLUSION

The nomogram that the combined radiomics signature and clinical risk factors showed a satisfactory ability to predict IP-SCC.

Evaluation of narrow-band imaging in the diagnosis of sinonasal inverted papilloma

KEY POINTS

Narrow-band imaging (NBI) can be used to differentiate benign sinonasal lesions NBI can be used in the preoperative identification of sinonasal inverted papilloma Future studies can focus on NBI for recurrent inverted papilloma and surgical margin guidance.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Classification of nasal polyps and inverted papillomas using CT-based radiomics

OBJECTIVES

Nasal polyp (NP) and inverted papilloma (IP) are two common types of nasal masses. And their differentiation is essential for determining optimal surgical strategies and predicting outcomes. Thus, we aimed to develop several radiomic models to differentiate them based on computed tomography (CT)-extracted radiomic features.

METHODS

A total of 296 patients with nasal polyps or papillomas were enrolled in our study. Radiomics features were extracted from non-contrast CT images. For feature selection, three methods including Boruta, random forest, and correlation coefficient were used. We choose three models, namely SVM, naive Bayes, and XGBoost, to perform binary classification on the selected features. And the data was validated with tenfold cross-validation. Then, the performance was assessed by receiver operator characteristic (ROC) curve and related parameters.

RESULTS

In this study, the performance ability of the models was in the following order: XGBoost > SVM > Naive Bayes. And the XGBoost model showed excellent AUC performance at 0.922, 0.9078, 0.9184, and 0.9141 under four conditions (no feature selection, Boruta, random forest, and correlation coefficient).

CONCLUSIONS

We demonstrated that CT-based radiomics plays a crucial role in distinguishing IP from NP. It can provide added diagnostic value by distinguishing benign nasal lesions and reducing the need for invasive diagnostic procedures and may play a vital role in guiding personalized treatment strategies and developing optimal therapies.

CRITICAL RELEVANCE STATEMENT

Based on the extraction of radiomic features of tumor regions from non-contrast CT, optimized by radiomics to achieve non-invasive classification of IP and NP which provide support for respective therapy of IP and NP.

KEY POINTS

• CT images are commonly used to diagnose IP and NP. • Radiomics excels in feature extraction and analysis. • CT-based radiomics can be applied to distinguish IP from NP. • Use multiple feature selection methods and classifier models. • Derived from real clinical cases with abundant data.

Development and validation of apparent diffusion coefficient histogram-based nomogram for predicting malignant transformation of sinonasal inverted papilloma

OBJECTIVES

To develop and validate a nomogram based on whole-tumour histograms of apparent diffusion coefficient (ADC) maps for predicting malignant transformation (MT) in sinonasal inverted papilloma (IP).

METHODS

This retrospective study included 209 sinonasal IPs with and without MT, which were assigned into a primary cohort (n = 140) and a validation cohort (n = 69). Eight ADC histogram features were extracted from the whole-tumour region of interest. Morphological MRI features and ADC histogram parameters were compared between the two groups (with and without MT). Stepwise logistic regression was used to identify independent predictors and to construct models. The predictive performances of variables and models were assessed using the area under the curve (AUC). The optimal model was presented as a nomogram, and its calibration was assessed.

RESULTS

Four morphological features and seven ADC histogram parameters showed significant differences between the two groups in both cohorts (all p < 0.05). Maximum diameter, loss of convoluted cerebriform pattern, ADC10th and ADCSkewness were identified as independent predictors to construct the nomogram. The nomogram showed significantly better performance than the morphological model in both the primary (AUC, 0.96 vs 0.88; p = 0.006) and validation (AUC, 0.96 vs 0.88; p = 0.015) cohorts. The nomogram showed good calibration in both cohorts. Decision curve analysis demonstrated that the nomogram is clinically useful.

CONCLUSIONS

The developed nomogram, which incorporates morphological MRI features and ADC histogram parameters, can be conveniently used to facilitate the pre-operative prediction of MT in IPs.

Differentiation between atypical sinonasal non-Hodgkin's lymphoma and inverted papilloma

AIM

To seek additional magnetic resonance imaging (MRI) features to improve the accuracy of differentiation between atypical sinonasal non-Hodgkin's lymphoma (NHL) and inverted papilloma (IP) using conventional MRI and apparent diffusion coefficient (ADC) maps.

MATERIALS AND METHODS

MRI examinations from 44 atypical cases (21 NHLs and 23 IPs) in sinonasal regions were reviewed retrospectively. Imaging features included tumour laterality, extension, T1-weighted imaging (WI)/T2WI signal intensity homogeneity and ratios, enhancement homogeneity and ratios, and ADC_mean.

RESULTS

In cases of NHL, homogeneous signal intensity was often observed on T2WI, which was homogeneous and significantly less enhanced than the turbinate, with lower ADC_mean. Whereas in IPs, heterogeneous signal intensity was seen on T2WI, which was heterogeneous and of comparable enhancement to the turbinate, and higher ADC_mean values were commonly seen. An ADC_mean cut-off point of 1.10 × 10^-3 mm²/s achieved 100% sensitivity, 90% specificity, and 90% accuracy. In addition, special features were observed that support the distinction between the two tumours, including intestinal pattern enhancement in NHL and spot-like appearance on T2WI and enhancement in IP.

CONCLUSIONS

ADC_mean was the most valuable metric for differentiating between the atypical sinonasal NHLs and IPs.

Development and Validation of a Clinical Prediction Model to Diagnose Sinonasal Inverted Papilloma Based on Computed Tomography Features and Clinical Characteristics

Objectives: Sinonasal inverted papilloma (SNIP) is one of the most common benign tumors of the nasal cavity and sinuses and is at risk for recurrence and malignant transformation. It is crucial to precisely predict SNIP before surgery to determine the optimal surgical technique and prevent SNIP recurrence. This study aimed to evaluate the diagnostic value of computed tomography (CT) features and SNIP clinical characteristics and to develop and validate a clinically effective nomogram. Methods: Here, 267 patients with SNIP and 273 with unilateral chronic rhinosinusitis with/without nasal polyps were included. Patient's demographic and clinical characteristics (i.e., gender, age, nasal symptoms, history of sinus surgery, smoking, and alcohol dependence) and CT features (i.e., lobulated/wavy edge, air sign, focal hyperostosis, diffuse hyperostosis, focal osseous erosion, and CT values) were recorded. Independent risk factors were screened using logistic regression analysis. A nomogram model was developed and validated. Results: Logistic regression analysis showed that age, facial pain/headache, history of sinus surgery, lobulated/wavy edge, air sign, focal hyperostosis, focal osseous erosion, and CT values were independent predictors of SNIP. A nomogram comprising these 8 independent risk factors was established. The area under the curve (AUC) for the training set was .960 (95% CI, .942-.978) and the AUC for the validation set was .951 (95% CI, .929-.971). Conclusion: The obtained results suggested that the nomogram based on age, facial pain/headache symptoms, history of sinus surgery, and CT characteristics had an excellent diagnostic value for SNIP.

MRI radiomics-based machine learning model integrated with clinic-radiological features for preoperative differentiation of sinonasal inverted papilloma and malignant sinonasal tumors

Objective

To explore the best MRI radiomics-based machine learning model for differentiation of sinonasal inverted papilloma (SNIP) and malignant sinonasal tumor (MST), and investigate whether the combination of radiomics features and clinic–radiological features can produce a superior diagnostic performance.

Methods

The database of 247 patients with SNIP (n=106) or MST (n=141) were analyzed. Dataset from scanner A were randomly divided into training set (n=135) and test set 1 (n=58) in a ratio of 7:3, and dataset from scanner B and C were used as an additional independent test set 2 (n=54). Fourteen clinic-radiological features were analyzed by using univariate analysis, and those with significant differences were applied to construct clinical model. Based on the radiomics features extracted from single sequence (T2WI or CE-T1WI) and combined sequence, four commonly used classifiers (logistic regression (LR), support vector machine (SVM), decision tree (DT) and k-nearest neighbor (KNN)) were employed to constitute twelve different machine learning models, and the best-performing one was confirmed as the optimal radiomics model. Furthermore, a combined model incorporated best radiomics feature subsets and clinic-radiological features was developed. The diagnostic performances of these models were assessed by the area under the receiver operating characteristic (ROC) curve (AUC) and the calibration curves.

Results

Five clinic-radiological features (age, convoluted cerebriform pattern sign, heterogeneity, adjacent bone involvement and infiltration of surrounding tissue) were considered to be significantly different between the tumor groups (P < 0.05). Among the twelve machine learning models, the T2WI-SVM model exhibited optimal predictive efficacy for classification tasks on the two test sets, with the AUC of 0.878 and 0.914, respectively. For three types of diagnostic models, the combined model achieved highest AUC of 0.912 (95%CI: 0.807-0.970) and 0.927 (95%CI: 0.823-0.980) for differentiation of SNIP and MST in test 1 and test 2 sets, which performed prominently better than clinical model (P=0.011, 0.005), but not significantly different from the optimal radiomics model (P=0.100, 0.452).

Conclusion

The machine learning model based on T2WI sequence and SVM classifier achieved best performance in differentiation of SNIP and MST, and the combination of radiomics features and clinic-radiological features significantly improved the diagnostic capability of the model.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Unique volatile metabolite signature of sinonasal inverted papilloma detectible in plasma and nasal secretions

BACKGROUND

Sinonasal inverted papilloma (SNIP) is a benign neoplasm with aggressive features, including a high recurrence rate and a propensity for malignant transformation. Accurate diagnosis with complete resection and the need for close long-term surveillance is widely accepted as standard management. In this study, we investigate whether SNIP produces a unique volatile metabolite signature, which may ultimately lead to a novel approach to diagnose and monitor SNIP.

METHODS

Whole blood and nasal secretions from patients with SNIP and healthy age, sex, and smoking-status matched controls, were collected. There were 56 blood samples and 42 nasal secretion samples collected. The volatile metabolite signature of SNIP plasma and nasal secretion samples were compared to those of healthy controls using chromatograms.

RESULTS

Seventy-two volatiles were identified in plasma samples. MANOVA results, even when controlled for smoking-status, indicated toluene as a significant univariate result with lower levels of toluene identified in SNIP plasma samples than healthy control plasma samples. A linear discriminant analysis (LDA) model for plasma volatiles correctly classified 23/24 SNIP patients and 26/27 control patients, with a cross-validation error rate of 6.02%. Sixty-nine volatiles were identified in nasal samples. For nasal secretion samples, no single univariate response was significant. The LDA model correctly classified 21/21 SNIP patients and 11/12 control patients, with a cross-validation error rate of 6.55%.

CONCLUSIONS

This study suggests that SNIP produces a unique, detectible volatile metabolite signature. With further investigation, this can have dramatic clinical implication for diagnosis and monitoring. While most volatile metabolite studies have investigated solid organ malignancy, this novel study investigates a benign sinonasal neoplasm utilizing nasal secretions and plasma as an analysis medium, representing the first such study. This article is protected by copyright. All rights reserved.

Deep learning classification of inverted papilloma malignant transformation using 3D convolutional neural networks and magnetic resonance imaging

BACKGROUND

Distinguishing benign inverted papilloma (IP) tumors from those that have undergone malignant transformation to squamous cell carcinoma (IP-SCC) is important but challenging to do preoperatively. Magnetic resonance imaging (MRI) can help differentiate these 2 entities, but no established method exists that can automatically synthesize all potentially relevant MRI image features to distinguish IP and IP-SCC. We explored a deep learning approach, using 3-dimensional convolutional neural networks (CNNs), to address this challenge.

METHODS

Retrospective chart reviews were performed at 2 institutions to create a data set of preoperative MRIs with corresponding surgical pathology reports. The MRI data set included all available MRI sequences in the axial plane, which were used to train, validate, and test 3 CNN models. Saliency maps were generated to visualize areas of MRIs with greatest influence on predictions.

RESULTS

A total of 90 patients with IP (n = 64) or IP-SCC (n = 26) tumors were identified, with a total of 446 images of distinct MRI sequences for IP (n = 329) or IP-SCC (n = 117). The best CNN model, All-Net, demonstrated a sensitivity of 66.7%, specificity of 81.5%, overall accuracy of 77.9%, and receiver-operating characteristic area under the curve of 0.80 (95% confidence interval, 0.682-0.898) for test classification performance. The other 2 models, Small-All-Net and Elastic-All-Net, showed similar performance levels.

CONCLUSION

A deep learning approach with 3-dimensional CNNs can distinguish IP and IP-SCC with moderate test classification performance. Although CNNs demonstrate promise to enhance the prediction of IP-SCC using MRIs, more data are needed before they can reach the predictive value already established by human MRI evaluation.

Investigation of MRI-based radiomics model in differentiation between sinonasal primary lymphomas and squamous cell carcinomas

PURPOSE

To develop and validate an MRI-based radiomics model in differentiation between sinonasal primary lymphomas and squamous cell carcinomas (SCCs).

MATERIALS AND METHODS

One-hundred-and-fifty-four patients were enrolled (74 individuals with SCCs and 80 with lymphomas). After feature analysis and feature selection with variance threshold and least absolute shrinkage and selection operator (LASSO) methods, an MRI-based radiomics model with the support vector machine (SVM) classifier was constructed in differentiation between lymphomas and SCCs. Areas under the receiver operating characteristic curves (AUCs) of the MRI-based radiomics model were compared with those of radiologists using Delong test.

RESULTS

Five features (T1 original shape Compactness2, T1 wavelet-HHH first-order Total Energy, T2 wavelet-HLH GLCM Informational Measure of Correlation1, T1 wavelet-LHL GLCM Inverse Variance and T1 square GLRLM Long Run Low Gray Level Emphasis) were finally selected in the radiomics model. The AUC values in differentiation between lymphomas and SCCs were 0.94 for the training dataset and 0.85 for the validation dataset, respectively. For all the patient datasets, the AUC values of radiomics model, readers 1, 2 and 3 were 0.92, 0.76, 0.77 and 0.80, respectively. For the validation datasets, no significant difference was found between the AUCs of the radiomics model and those of the three radiologist (P = 0.459, 0.469, 0.738 for radiologist 1, 2 and 3, respectively).

CONCLUSION

An MRI-based radiomics model can help to differentiate sinonasal lymphomas from SCCs with high accuracy.

High CT values relative to the brainstem differentiate inverted papillomas from nasal polyps

OBJECTIVES

A diagnostic indicator for the differentiation of inverted papillomas (IPs) from inflammatory nasal polyps (NPs) has not been established. This study aimed to evaluate whether CT attenuation values relative to those of the brainstem (relative CT number) could be useful for differentiating IPs from NPs.

MATERIAL AND METHODS

Consecutive patients who were pathologically diagnosed with IP or NP between 2005 and 2019 were retrospectively identified. Relative CT numbers were compared between the two patient groups. The factors with predictive power for differentiating IPs from NPs were identified by univariate and multivariate logistic regression analyses.

RESULTS

One hundred and twenty-two sinonasal masses were finally analysed (IP, 51 cases; NP, 71 cases). Relative CT numbers were significantly higher in IP than in NP (P < 0.001). Univariate logistic regression analysis showed relative CT number, bone erosion and bone thickening to have predictive value for differentiating IPs from NPs (relative CT number, P < 0.001; bone erosion, p = 0.04; bone thickening, P < 0.001). In the multivariate logistic regression analysis, relative CT number and bone thickening had predictive value for distinguishing IP from NP (relative CT number, p < 0.001; bone thickening, p = 0.02). The optimum cut off value calculation from the area under the receiver operating characteristics curve indicated that a relative CT number >1.3 was significantly associated with IP (sensitivity, 72.6%; specificity, 87.3%). Within cases not showing bone thickening, only the relative CT number was a predictive factor for differentiating IPs from NPs in the univariate analysis.

CONCLUSIONS

High relative CT numbers could potentially indicate IP, and their measurement could provide a basis for differentiating IPs from NPs.

Evaluation of narrow band imaging for diagnosis of unilateral nasal lesions

OBJECTIVES

This study aimed to investigate the effect of narrow band imaging (NBI) examination on differentiating diagnosis between benign and malignant neoplasms involving nasal cavity.

DESIGN, SETTING, PARTICIPANTS

A retrospective study was conducted to analyse cases from January 2018 to December 2019 at a single centre. A total of 188 consecutive patients who were newly diagnosed with lesions in unilateral nasal cavity underwent complete examination with white light endoscopy (WLE) and NBI endoscopy. Biopsy specimens were harvested from the target lesions and sent to the pathologist for definite diagnosis. Participants with a history of congenital malformation, trauma and surgery in nasal cavity were excluded from the study.

MAIN OUTCOME MEASURES

Endoscopic diagnosis was assessed using sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV, respectively).

RESULTS

In identifying benign and malignant lesions of nasal cavity, NBI had a significant higher sensitivity (92.7% vs 70.7%, P = .020) and NPV (98% vs 92.3%, P = .032) than WLE, but there were no significant differences between NBI and WLE in specificity (98.6% vs 97.3%, P = .684), accuracy (97.3% vs 91.5%, P = .416) and PPV (95% vs 87.9%, P = .400).

CONCLUSION

NBI as an emerging technique can improve the diagnostic accuracy by distinguishing benign and malignant lesions in nasal cavity and remains a promising and helpful adjunct to the endoscopy techniques.

An MRI-Based Radiomic Nomogram for Discrimination Between Malignant and Benign Sinonasal Tumors

BACKGROUND

Preoperative discrimination between malignant and benign sinonasal tumors is important for treatment plan selection.

PURPOSE

To build and validate a radiomic nomogram for preoperative discrimination between malignant and benign sinonasal tumors.

STUDY TYPE

Retrospective.

POPULATION

In all, 197 patients with histopathologically confirmed 84 benign and 113 malignant sinonasal tumors.

FIELD STRENGTH/SEQUENCES

Fast-spin-echo (FSE) T₁ -weighted and fat-suppressed FSE T₂ -weighted imaging on a 1.5T and 3.0T MRI.

ASSESSMENT

T₁ and fat-suppressed T₂ -weighted images were selected for feature extraction. The least absolute shrinkage selection operator (LASSO) algorithm was applied to establish a radiomic score. Multivariate logistic regression analysis was applied to determine independent risk factors, and the radiomic score was combined to build a radiomic nomogram. The nomogram was assessed in a training dataset (n = 138/3.0T MRI) and tested in a validation dataset (n = 59/1.5T MRI).

STATISTICAL TESTS

Independent t-test or Wilcoxon's test, chi-square-test, or Fisher's-test, univariate analysis, LASSO, multivariate logistic regression analysis, area under the curve (AUC), Hosmer-Lemeshow test, decision curve, and the Delong test.

RESULTS

In the validation dataset, the radiomic nomogram could differentiate benign from malignant sinonasal tumors with an AUC of 0.91. There was no significant difference in AUC between the combined radiomic score and radiomic nomogram (P > 0.05), and the radiomic nomogram showed a relatively higher AUC than the combined radiomic score. There was a significant difference in AUC between each two of the following models (the radiomic nomogram vs. the clinical model, all P < 0.001; the combined radiomic score vs. the clinical model, P = 0.0252 and 0.0035, respectively, in the training and validation datasets). The radiomic nomogram outperformed the radiomic scores and clinical model.

DATA CONCLUSION

The radiomic nomogram combining the clinical model and radiomic score is a simple, effective, and reliable method for patient risk stratification.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY STAGE: 2.

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

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

Clinical assessment, diagnosis and management of patients with unilateral sinonasal disease

OBJECTIVES

Unilateral sinonasal disease is commonly encountered in practice and represents an issue of major concern since neoplasms may mimic inflammatory conditions. This paper aims to describe the demographic, clinical and radiological patterns of unilateral pathologies and, accordingly, to establish a guiding algorithm for diagnosis and management.

MATERIAL AND METHODS

We conducted a retrospective review of medical records of patients with unilateral sinus opacification on CT scan who underwent endoscopic nasal surgery in our department from January 2011 to December 2017.

RESULTS

Of the 150 patients included, 97(64.7%) and 53(35.3%) had inflammatory and neoplastic pathology, respectively. In the neoplastic group, malignancy was present in 35% of patients. Neoplastic conditions were more common in males (p=0.02) and older patients (56±18 years vs. 38±18, p<.01). Nasal mass or polyp was observed in 56.7% patients. Chronic sinusitis was the most prevalent inflammatory condition, whereas inverted papilloma and osteoma were the most frequent neoplasms. Facial neuralgia, paraesthesia, epistaxis and, on CT scan, superior Lund-Mackay scores, bone remodelling and erosion were significantly more common in neoplastic conditions. Excellent agreement between punch biopsy and postoperative histological results was obtained (k=.883, p<.001).

CONCLUSION

A sequential and careful management of unilateral lesions is mandatory. Based on our experience, we propose that, as routine, physical examination should be complemented with nasal endoscopy, CT scan and punch biopsy, in case of visible mass. Although clinical and radiological information might raise suspicion of some conditions, final diagnosis can only be established with histological examination of the surgical specimen.

Co-occurrence of Nasal Polyps and Neoplasms of the Canine Nasal Cavity

Nasal polyps in dogs are space-occupying soft-tissue masses that have been encountered concurrently with intranasal neoplasia in surgical biopsy specimens. The proportion of nasal polyp co-occurrence with primary nasal tumors was examined, and follow-up biopsies on dogs initially diagnosed with nasal polyp were reviewed. Histologic sections from 321 cases of intranasal neoplasia and 50 cases of nasal polyp from 2004 to 2017 were reviewed. Of the 321 cases of intranasal neoplasia, 51 (16%) had concurrent nasal polyps, and most of these (47/51) had intranasal carcinoma. Twenty-five of the 50 dogs with a primary diagnosis of nasal polyp were rebiopsied, and the diagnoses in these subsequent biopsies were nasal polyp in 15, malignant neoplasm in 9, and intranasal nematode in 1. Nasal polyps occurred frequently in conjunction with nasal carcinoma. In dogs with a diagnosis of nasal polyp, repeat biopsy to reveal possible neoplasia is warranted.

Evaluation of multiparametric MRI differentiating sinonasal angiomatous polyp from malignant tumors

PURPOSE

Sinonasal angiomatous polyps (SAPs) can be misdiagnosed as malignant tumors due to aggressive clinical behaviors. The purpose of this study was to evaluate the diagnostic accuracy of multiparametric MRI in differentiating SAPs from malignant tumors.

METHODS

This retrospective study included 31 patients with pathologically proven SAPs and 36 patients with malignant tumors in maxillary sinus and nasal cavity. All the patients underwent conventional MRI and dynamic contrast-enhanced (DCE) MRI on 3T MR scanners. Diffusion-weighted (DW) MR imaging was performed in 45 patients. All the MR images were retrospectively analyzed independently by two authors.

RESULTS

Significant differences were found in T1 homogeneity, T2 signal intensity ratio, peripheral hypointense rim on T2WI, and soft tissue infiltration between SAP and malignant tumors (P = 0.004, < 0.001, < 0.001, and = 0.001, respectively). SAPs usually show heterogeneous signal intensity on T1WI, peripheral hypointense rim on T2WI, and higher T2 signal intensity ratio. The tumor size of SAP (4.01 ± 1.08 cm) was slightly smaller than that of malignant tumors (4.56 ± 1.12 cm) (P = 0.045). There were significant differences in DCE-MRI parameters including Tpeak, CImax, WR, TIC types, and progressive enhancement (P = 0.009, < 0.001, = 0.001, = 0.001, and < 0.001, respectively) between SAPs and malignant tumors. All the 31 SAPs showed progressive enhancement on DCE-MRI, while none of the malignant tumors showed progressive enhancement (accuracy 100%). The mean ADC of SAP (1.75 ± 0.30 × 10^-3 mm²/s) was higher than that of malignant tumors (1.18 ± 0.31 × 10^-3 mm²/s) (P < 0.001).

CONCLUSION

Multiparametric MRI showed high diagnostic performance in differentiating SAPs from malignant tumors. Progressive enhancement on DCE-MRI is the most effective feature of SAP.

Surgical outcomes of sinonasal inverted papilloma: a 17 year review

Introduction

Inverted papillomas represent one of the most common benign neoplasic lesions located in the sinonasal tract. Owing to the local erosive behavior, tendency to recur and the potential for malignant transformation, surgical management of inverted papillomas is often challenging.

Objective

This study aimed to analyze the surgical outcomes of patients with inverted papillomas, according to the Krouse staging and the different surgical approaches.

Methods

Retrospective study of patients diagnosed with sinonasal inverted papillomas who underwent surgical treatment between 2000 and 2016 at a tertiary referral hospital. Cases with follow-up less than 12 months were excluded. The rate and the time of recurrence were the main outcomes. Values of p < 0.05 were considered statistically significant.

Results

Thirty-six cases with mean age of 60 years, predominantly male (72%), were included. The follow-up period ranged from 1 to 16 years, with an average of 4.5 years. Krouse T1 Stage corresponded to 11.1%; T2 occurred in 50% of cases; while T3 and T4 Stages accounted for 30.6% and 8.3% of patients, respectively. Most cases were approached by an endoscopic technique alone (83.3%), with a recurrence rate of 13.3%. Patients treated via a combined or open approach revealed a recurrence of 16.7%. No differences in the recurrence rate were reported when comparing endoscopic surgery with the open or combined techniques. Krouse Stage T3 had a significant association with inverted papillomas recurrence (p = 0.023). All inverted papilloma relapses occurred up to 2 years post-operatively. One case of malignant transformation was recorded (2.7%).

Conclusion

Endoscopic surgery did not increase the recurrence rates and can be a safe and efficient alternative to open or combined techniques. The recurrence of inverted papillomas seem to be related to the persistence of the disease and tend to occur early after primary surgery. Krouse T3 Stages may be associated with a higher recurrence of inverted papillomas.

Incidental Histopathologic Finding of Sinonasal Inverted Papilloma Among Surgically Excised Polyps Increases the Risk of Tumor Recurrence

Inverted papilloma (IP) is a benign tumor remarkable for its tendency toward recurrence. Local relapse implicates incomplete resection concerning the bone adjacent to tumor base. The high false negative rates on biopsies, mainly when nasal polyps coexist, may affect the surgical management and outcomes. Our objective was to study the impact of preoperative histologic diagnosis in IP recurrence, particularly in patients with pre-surgical diagnosis of inflammatory polyps. A retrospective analysis of 62 patients treated for IP was conducted. Demographic data and information about smoking status, alcohol intake, tumor location, histology, presence of nasal polyps, staging, malignancy, previous biopsies and surgical approach were evaluated to identify factors associated with recurrence. Prevalence of nasal polyps was higher in patients with recurrence. Smoking history, alcohol abuse, staging, histologic type, malignancy and surgical approach were not associated with recurrence. The presence of nasal polyps at endoscopy was inversely associated with the diagnosis of IP at incisional biopsy. Incidental histologic diagnosis of IP after surgery increased the risk of recurrence more than tenfold. Biopsy reporting the diagnosis of IP previous to surgery was inversely associated to recurrence. In patients with IP, coexistence of nasal polyps at initial endoscopy and lack of pathological IP diagnosis prior to surgery are strongly associated with a higher risk of recurrence. When excisional biopsy reports IP incidentally, an early revision surgery should be considered in order to avoid future aggressive surgeries because of tumor recurrence.

Differentiation of olfactory neuroblastomas from nasal squamous cell carcinomas using MR diffusion kurtosis imaging and dynamic contrast-enhanced MRI

PURPOSE

To evaluate the use of magnetic resonance (MR) diffusion kurtosis imaging (DKI) and dynamic contrast-enhanced MR imaging (DCE-MRI) in the differentiation of olfactory neuroblastomas (ONBs) from squamous cell carcinomas (SCCs).

MATERIALS AND METHODS

DKI and DCE-MRI were performed in 17 patients with ONBs and 23 patients with SCCs on a 3T MR scanner. Parameters derived from DKI and DCE-MRI were measured and compared between ONBs and SCCs using an independent samples t-test. The sensitivity, specificity, accuracy, positive predictive values (PPV), negative predictive values (NPV), and the area under the receiver operating characteristic (ROC) curve were determined.

RESULTS

The mean kurtosis (K) value of ONBs was significantly higher than that of SCCs (P < 0.001), and the mean fractional volume in the extravascular extracellular space (V_e ) value of ONBs was lower than that of SCCs (P < 0.001). The ROC curve analyses yielded a cutoff K value of 0.953, with a sensitivity of 94.1%, a specificity of 69.6%, and an accuracy of 80.0%; the cutoff V_e value was 0.493, with a sensitivity of 70.6%, a specificity of 95.7%, and an accuracy of 85.0%. A parallel test with K value >0.953 or V_e value ≤0.493 achieved a sensitivity of 94.1%, a specificity of 100.0%, and an accuracy of 97.5% for differentiating ONBs from SCCs.

CONCLUSION

The K value of DKI and V_e value of DCE-MRI have potential use in the differentiation of ONBs and SCCs.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:354-361.

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

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Sinonasal inverted papilloma: From diagnosis to treatment

Inverted papilloma is a rare sinonasal tumor that mainly occurs in adults during the 5th decade. Three characteristics make this tumor very different from other sinonasal tumors: a relatively strong potential for local destruction, high rate of recurrence, and a risk of carcinomatous evolution. Etiology remains little understood, but an association with human papilloma virus has been reported in up to 40% of cases, raising the suspicions of implication in the pathogenesis of inverted papilloma. Treatment of choice is surgery, by endonasal endoscopic or external approach, depending on extension and tumoral characteristics. Follow-up is critical, to diagnose local relapse, which is often early but may also be late. The seriousness of this pathology lies in its association with carcinoma, which may be diagnosed at the outset or at recurrence during follow-up. It is important to diagnose recurrence to enable early treatment, especially in case of associated carcinoma or malignancy. A comprehensive review of the international literature was performed on PubMed and Embase, using the following search-terms: "sinonasal" [All Fields] AND ("papilloma, inverted" [MeSH Terms] OR ("papilloma" [All Fields] AND "inverted" [All Fields]) OR "inverted papilloma" [All Fields] OR ("inverted" [All Fields] AND "papilloma" [All Fields])). We reviewed all articles referring to sinonasal inverted papilloma published up to January 2015. The present article updates the state of knowledge regarding sinonasal inverted papilloma.

Improved performance in differentiating benign from malignant sinonasal tumors using diffusion-weighted combined with dynamic contrast-enhanced magnetic resonance imaging

Background:

Differentiating benign from malignant sinonsal lesions is essential for treatment planning as well as determining the patient's prognosis, but the differentiation is often difficult in clinical practice. The study aimed to determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can improve the performance in differentiating benign from malignant sinonasal tumors.

Methods:

This retrospective study included 197 consecutive patients with sinonasal tumors (116 malignant tumors and 81 benign tumors). All patients underwent both DW and DCE-MRI in a 3-T magnetic resonance scanner. Two different settings of b values (0,700 and 0,1000 s/mm²) and two different strategies of region of interest (ROI) including whole slice (WS) and partial slice (PS) were used to calculate apparent diffusion coefficients (ADCs). A DW parameter with WS ADCs_b0,1000 and two DCE-MRI parameters (time intensity curve [TIC] and time to peak enhancement [Tpeak]) were finally combined to use in differentiating the benign from the malignant tumors in this study.

Results:

The mean ADCs of malignant sinonasal tumors (WS ADCs_b0,1000 = 1.084 × 10⁻³ mm²/s) were significantly lower than those of benign tumors (WS ADCs_b0,1000 = 1.617 × 10⁻³ mm²/s, P < 0.001). The accuracy using WS ADCs_b0,1000 alone was 83.7% in differentiating the benign from the malignant tumors (85.3% sensitivity, 81.2% specificity, 86.4% positive predictive value [PPV], and 79.5% negative predictive value [NPV]). The accuracy using DCE with Tpeak and TIC alone was 72.1% (69.1% sensitivity, 74.1% specificity, 77.5% PPV, and 65.1% NPV). Using DW-MRI parameter was superior than using DCE parameters in differentiation between benign and malignant sinonasal tumors (P < 0.001). The accuracy was 87.3% (90.5% sensitivity, 82.7% specificity, 88.2% PPV, and 85.9% NPV) using DW-MRI combined with DCE-MRI, which was superior than that using DCE-MRI alone or using DW-MRI alone (both P < 0.001) in differentiating the benign from the malignant tumors.

Conclusions:

Diffusion-weighted combined with DCE-MRI can improve imaging performance in differentiating benign from malignant sinonasal tumors, which has the potential to improve diagnostic accuracy and to provide added value in the management for these tumors.

Nose biopsy: a comparison between two sampling techniques

Pre operative biopsy is important in obtaining preliminary information that may help in tailoring the optimal treatment. The aim of this study was to compare two sampling techniques of obtaining nasal biopsy-nasal forceps and nasal scissors in terms of pathological results. Biopsies of nasal lesions were taken from patients undergoing nasal surgery by two techniques- with nasal forceps and with nasal scissors. Each sample was examined by a senior pathologist that was blinded to the sampling method. A grading system was used to rate the crush artifact in every sample (none, mild, moderate, severe). A comparison was made between the severity of the crush artifact and the pathological results of the two techniques. One hundred and forty-four samples were taken from 46 patients. Thirty-one were males and the mean age was 49.6 years. Samples taken by forceps had significantly higher grades of crush artifacts compared to those taken by scissors. The degree of crush artifacts had a significant influence on the accuracy of the pre operative biopsy. Forceps cause significant amount of crush artifacts compared to scissors. The degree of crush artifact in the tissue sample influences the accuracy of the biopsy.

Effectiveness of 3 T PROPELLER DUO diffusion-weighted MRI in differentiating sinonasal lymphomas and carcinomas

AIM

To evaluate the value of 3 T Periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) DUO diffusion-weighted MRI (DW-MRI) in differentiating sinonasal lymphomas from carcinomas.

MATERIALS AND METHODS

PROPELLER DUO DW-MRI was performed in 23 patients with sinonasal lymphomas and 28 patients with carcinomas histologically confirmed at 3 T MRI. Apparent diffusion coefficients (ADCs) were obtained with two different b-values (b = 0 and 700 s/mm(2), b = 0 and 1000 s/mm(2)) and two different regions of interest (ROIs) sampling strategies [whole section (WS), partial section (PS)], respectively. Difference in ADCs between sinonasal lymphomas and carcinomas was evaluated using the independent samples t-test or Mann-Whitney U-test. The utility of ADC thresholds for discriminating between them was evaluated by receiver operating characteristic analysis.

RESULTS

ADCs of sinonasal lymphomas (WS ADCb0,700, 0.838 × 10(-3) mm(2)/s) were significantly (p < 0.001) lower than those of carcinomas (WS ADCb0,700, 1.396 × 10(-3) mm(2)/s). Using a WS ADC b0,700 value of 1.040 × 10(-3) mm(2)/s as the threshold value effectively differentiated sinonasal lymphomas from carcinomas with 100% sensitivity, 82.1% specificity, and 82.1% positive and 100% negative predictive values and 90.2% accuracy (b = 0, 700 s/mm(2)). There was no significant difference in diagnostic ability between different b-values settings (p > 0.05) and different sampling strategies of ROIs (p > 0.05), respectively. Additionally, there was significant differences in the ADCs between diffuse large B-cell lymphomas and natural killer (NK)/T-cell lymphomas (p < 0.05).

CONCLUSION

PROPELLER DUO DW-MRI can effectively differentiate sinonasal lymphomas from carcinomas.

The usefulness of preoperative biopsy in unilateral nasal masses

Unilateral nasal masses are considered suspicious for proliferative diseases. Several tools are routinely used to investigate unilateral lesions such as imaging and nasal biopsy. This study investigated the usefulness of nasal biopsy in predicting the actual nature of unilateral lesions. Preoperative nasal biopsy pathological results were compared with the final pathology obtained during an operation. Forty-six patients with unilateral nasal masses were included in the study group. In 40 patients the final pathology was similar to the preoperative nasal biopsy. In three patients the biopsy specimen was a benign polyp and the final pathology was of an inverted papilloma in two patients and hemangiopericytoma in one patient. In two patients the biopsy specimen was suspicious for an inverted papilloma and the final pathology was a benign polyp. In one patient the biopsy specimen was chordoma and the final pathology was osteosarcoma. The total agreement was 86.9%. The kappa value was 81.2%. Preoperative nasal biopsy is important and useful in evaluating unilateral nasal masses.

Retrospective analysis of 26 cases of inverted nasal papillomas

Inverted papilloma (IP) comprises 0.5-4% of benign nasal tumors. The importance is shown by local aggressiveness, a high recurrence rate and the possibility of malignant transformation. The treatment is controversial, but endoscopic approaches tends to be the choice today.

Aim

To describe clinical, epidemiological and treatment of IP cases in a tertiary hospital.

Methods

Retrospective study consisting of chart reviews of 26 patients diagnosed with IP; evaluation of tumor location, clinical staging, follow up, tumor recurrence, malignancy, type of surgery and postoperative complications.

Results

There were 13 men and 13 women, the mean age was 57.8 years. The mean follow up time was 29.4 months; the recurrence rate was 7.6%. There was a preponderance of T3 and T4 tumors and a 3.8% malignancy rate. All patients underwent surgical treatment, mostly endonasal endoscopic surgery.

Conclusion

IP is an uncommon nasal tumor that originates mainly in the lateral nasal wall, but it also affects the paranasal sinuses. Advances in endoscopic surgery are gaining room due to lower invasiveness and success rates similar to traditional external techniques for completely resecting the tumor. There is a lower recurrence rate, and endoscopy a definitive treatment for malignancy cases in this study.

Recurrence of atypical fibroxanthoma. Diagnosis and treatment

INTRODUCTION

 The soft tissue sarcomas (SPM) accounts for only 1% of malignant tumors of the adult population. The SPM is the most frequent malignant fibrous histiocytoma (MFH) that exhibits behavior characterized by the tendency to invasion of adjacent tissue and metastatic spread early. One of its variants is the atypical fibroxanthoma (FA).

OBJECTIVE

 To describe a case of probable recurrence of AF underwent surgical treatment and presentation of a literature review.

CASE REPORT

 Patient female, 63 years, presenting with a mass in the face about four inches and a history of prior resection of the lesion in the same topography. The patient underwent surgical resection with a diagnosis of AF.

CONCLUSION

 The FA is a rare tumor histological diagnosis difficult. The correct histological diagnosis and patient follow-up are essential.

Indications, technique, safety, and accuracy of office-based nasal endoscopy with biopsy for sinonasal neoplasm

BACKGROUND

Office-based nasal endoscopy with biopsy may provide histopathological diagnosis in patients with sinonasal neoplasms while avoiding operative biopsy. The objective of this study was to describe the technique, safety, and accuracy of office-based nasal endoscopy with biopsy for a primary indication of sinonasal neoplasm.

METHODS

A retrospective review of the indications, complications, and results of office-based nasal endoscopy with biopsy for primary indication of neoplasm was performed. When available, comparison was made between the histopathological findings at biopsy vs surgery.

RESULTS

A total of 61 patients underwent 69 office-based endoscopic sinonasal biopsies during the 3-year study period. The results of the biopsies in this cohort included inflammatory changes in 36 procedures (52%), benign neoplasm in 14 procedures (20%), malignant lesion in 12 procedures (17%), nondiagnostic tissue in 5 specimens (7%), and granulomatous/vasculitic lesion in 2 procedures (3%). Comparison of office biopsy vs surgery in 28 procedures (25 patients) revealed agreement in 23 procedures (82%), 2 false-negative results for malignancy, 1 false-negative result for hemangioma, and 1 false-negative result and 1 false-positive result each for inverted papilloma. Accuracy analysis for a diagnosis of neoplasm yielded a sensitivity of 71%, specificity of 93%, false-positive rate of 9%, and false-negative rate of 24%. No major complications were experienced.

CONCLUSION

Office-based nasal endoscopy with biopsy represents a safe and important diagnostic tool in the evaluation of sinonasal neoplasms. The procedure is generally safe and provides diagnostic information that may alter treatment decisions. Limitations of the procedure do exist, notably issues related to accuracy.