Computed Tomography Imaging Patterns of Sinonasal Inverted Papillomas: Comparison of Primary and Recurrent Disease.

OBJECTIVE: To analyze clinical and radiographic features that may impact the rate of focal hyperostosis (FH) on computed tomography (CT) for primary and recurrent sinonasal inverted papillomas (IPs) as well as highlight factors that may affect concordance between FH and IP true attachment point (TAP). METHODS: All IPs resected between 2006 and 2022 were retrospectively reviewed. CTs were read by a neuroradiologist blinded to operative details. IP with malignancy was excluded. Operative reports and long-term follow-up data were evaluated. RESULTS: Of 92 IPs, 60.1% had FH, 25% had no CT bony changes, and 20.7% were revision cases. The recurrence rate for rhinologists was 10.5% overall and 7.3% for primary IPs. Primary and revision IPs had a similar rate of FH (63% vs. 52.6%; p = 0.646) and FH-TAP agreement (71.7% vs. 90%; p = 0.664). Nasal cavity IPs, especially with septal attachment, were more likely to lack bony changes on CT (57.1%) compared to other subsites (p = 0.018). Recurrent tumors were 16 mm larger on average (55 mm vs. 39 mm; p = 0.008). FH (75.0% vs. 60.9%; p = 0.295), FH-TAP concordance (91.7% vs. 74.4%; p = 0.094), and secondary IP (18.8% vs. 20.3%; p = 0.889) rates were similar between recurrent and nonrecurrent tumors. CONCLUSION: Primary and revision IPs have a similar rate of FH and FH-TAP agreement. Nasal cavity IPs are less likely to exhibit bony CT changes. Lower recurrence was associated with smaller size and fellowship training but not multiple TAPs, revision, FH absence, or FH-TAP discordance. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1591-1596, 2024.

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.

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.

Nasal obstruction in a 14 year old girl caused by a huge middle turbinate mucocele appearing radiologically as an inverted papilloma.

Introduction: We present a case of a fourteen year old girl who presented with a large intra-nasal mass to the ENT team at a district general hospital in the UK. Presentation of case: The girl presented predominantly with nasal obstruction and some symptoms of allergic rhinitis. Imaging revealed a large lesion abutting the skull base and causing bony remodelling with marked septal deviation. Based both on CT and MRI imaging, the reporting (non-head and neck) radiologist suggested inverted papilloma as a differential diagnosis. Intra-operative exploration in fact revealed a very large left middle turbinate mucocele extending to the left frontal sinus. The mass was excised endoscopically without complications. Discussion: Although concha bullosa of the middle turbinate of the nose are common, development of a mucocele within them is far less common and for such a mucocele to develop to this size in a child is extremely rare. The egg shell lining of the lesion can be a tell-tale sign of their aetiology when taken alongside other radiological factors. This case highlights challenges in radiological diagnosis of intra-nasal masses in children, which can lead to delays and increased anxiety. Conclusion: When assessing nasal masses in children it is important to keep a wide differential due to the challenges of diagnosis. A close conversation should be had with local head and neck radiologists and, of course, where there is a unilateral nasal mass tissue sampling is essential and may be taken as part of a full excision where clinically indicated.

Extended sphenoidotomy combined with transpterygoid approach for sphenoidal sinus inverted papilloma.

PURPOSE: Inverted papilloma of the sphenoid sinus (IPSS) is a rare tumor with debated surgical management due to its proximity to vital structures. The aim of this manuscript is to highlight the role of a transpterygoid approach (TPA) and pedicle-orientated strategy in case of involvement of critical structures in IPSS and compare it with data from the literature. METHODS: Patients with primary IPSS between January 2000 and June 2021 were included. Pre-operative CT/MRI were analyzed to classify the pneumatization of the SS and predict the insertion point of the inverted papilloma. All patients were treated with a trans-sphenoidal approach which was combined with a TPA in case of lateral insertion point. A systematic search was also performed to summarize the available literature. RESULTS: Twenty-two patients were treated for IPSS. By CT, the SS was categorized with type III pneumatization in 72.8% of cases. Eleven patients (50%) were treated with a TPA with a statistical association with the insertion point on the SS lateral wall (p = 0.01), rather than a SS pneumatization (p = 0.63). The overall success was 95.5% after a mean follow-up of 35.9 months. For the literature, 26 publications were included on 97 patients and described a trans-sphenoidal approach with a success rate of 84.6% after a mean follow-up of 24.5 months. CONCLUSION: IPSS is generally treated with a sphenoidotomy approach, although in selected cases, a TPA should be preferred to expose the whole SS lateral wall though allowing a complete pedicled oriented resection of the tumor.

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.

Predictive Value of Magnetic Resonance Imaging Multi-parametric Analysis for Malignant Transformation of Sinonasal Inverted Papilloma: A Comprehensive Prediction Model.

OBJECTIVE: Accurate preoperative prediction of sinonasal inverted papilloma (SNIP) malignant transformation is essential and challenging. In this study, 3.0T magnetic resonance was used for qualitative, quantitative, and multi-parametric analysis to evaluate the predictive value of magnetic resonance imaging (MRI) in malignant transformation. METHODS: The data of patients with SNIP (n=83) or SNIP-transformed squamous cell carcinoma (SNIP-SCC) (n=21) were analysed retrospectively. Univariate analysis and multivariate logistic regression were used to establish models to predict the risk factors for the malignant transformation of SNIP. Receiver operating characteristic (ROC) curves were used to evaluate the ability of independent risk factors and related combination models to predict the malignant transformation of SNIP. RESULTS: Convoluted cerebriform pattern (CCP) mutation, apparent diffusion coefficient ratio (ADCr), and wash-in index (WII) 2 and 3 were independent risk factors for predicting malignant transformation of SNIP, with area under the ROC curve (AUC) values of 0.845, 0.862, 0.727, and 0.704, respectively. The AUC of the quantitative parameter model combined with ADCr and WII 2 and 3 was 0.910 for diagnosing malignant transformation. The AUC of the comprehensive model comprising all independent risk factors was 0.937, with a sensitivity, specificity, and accuracy of 90.48%, 90.36%, and 92.31%, respectively. CONCLUSION: Compared with assessing independent risk factors of CCP mutation, ADCr and WII, and the quantitative parameter model, the comprehensive model could improve the differential diagnosis ability of SNIP and SNIP-SCC, which provides an important imaging basis for the possible accurate preoperative evaluation of the malignant transformation of SNIP.

Utility of flexible interventional endoscopy in endoscopic sinus surgery: a case series.

PURPOSE: During endoscopic sinus surgery (ESS), difficult-to-reach pathologies need an extended endoscopic approach or an external approach. We started to use a flexible interventional endoscope (FIE) to evaluate the necessity of those approaches. The study's objective is to describe our experience and define patients who could benefit from this technique. METHODS: We reviewed every patient who benefited from FIE associated with ESS at our tertiary University Hospital between January 2021 and February 2022. RESULTS: During this period, we did 107 ESS, and 14 patients benefited from the FIE, representing 13% of our ESS. The median duration of the flexible endoscopy time was 14 min (4-38 min). We identified three groups of patients who can benefit from the FIE. The first one is for patients with a fungal infection, to control and to clean lateral recesses in a noninvasive manner. The second one is for patients with a pathology of the lateral frontal sinus, to remove the frontoethmoidal cells or mucocele with the biopsy forceps through the working channel. The third group is for patients with inverted papillomas, to precisely identify the insertion and to decide on the most appropriate surgical approach. CONCLUSIONS: In selected cases, using flexible endoscopy during ESS helps decide the optimal surgical approach and sometimes treat the pathology through a limited approach. Prospective studies for each group of patients are needed to confirm the benefit of this new combined procedure.

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 ADCmean. 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 ADCmean. Whereas in IPs, heterogeneous signal intensity was seen on T2WI, which was heterogeneous and of comparable enhancement to the turbinate, and higher ADCmean values were commonly seen. An ADCmean 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: ADCmean was the most valuable metric for differentiating between the atypical sinonasal NHLs and IPs.

Dual-Energy Computed Tomography-Derived Iodine Density and Spectral Attenuation Analysis for Differentiation of Inverted Papilloma and Sinonasal Squamous Cell Carcinoma/Lymphoma.

OBJECTIVE: This study aimed to assess the value of dual-energy computed tomography for differentiation of inverted papilloma from squamous cell carcinoma (SCC)/lymphoma. METHODS: Twenty-eight patients with pathologically diagnosed inverted papilloma or SCC/lymphoma underwent contrast-enhanced dual-energy computed tomography. Qualitative features (laterality, location, enhancement pattern, border, necrosis, hemorrhage, calcification, bone destruction, pterygopalatine fossa extension, adjacent invasion, and perineural spreading) and quantitative features (iodine density and spectral attenuation curve slope) were analyzed. Optimal cutoff thresholds of diagnostic efficacy were generated. RESULTS: Fifteen patients had inverted papilloma, and 13 had malignancy (5 SCC and 8 lymphoma). Computed tomography findings of bilateral lesions, sphenoid sinus involvement, pterygopalatine fossa extension, and adjacent invasion were significantly associated with SCC/lymphoma. The iodine density was significantly higher in SCC/lymphoma (2.46 ± 0.22 mg/mL) than in inverted papilloma (1.42 ± 0.46 mg/mL; P = 0.001). An iodine density threshold of 1.74 mg/mL had a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 92.3%, 86.7%, 92.9%, 85.7%, and 90.3%, respectively. The spectral attenuation curve slope was significantly higher in SCC/lymphoma (4.35 ± 0.27 HU/keV) than in inverted papilloma (2.72 ± 0.88 HU/keV; P = 0.001). A spectral attenuation curve slope threshold of 3.34 HU/keV had a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 92.3%, 86.7%, 92.9%, 85.7%, and 90.8%, respectively. CONCLUSIONS: Squamous cell carcinoma/lymphoma had a significantly higher iodine density and spectral attenuation curve slope than inverted papilloma. Using optimal quantitative measurement thresholds provides high diagnostic efficacy.

Inverted papilloma with bilateral origin. A case report and review of the literature.

AIM: To show a rare case of inverted papilloma with bilateral origin treated with endoscopic approach MATERIAL OF STUDY: The authors reported the unusual case of a 71-year-old male patient with a growing mass occupying both nasal cavities. The patient complained bilateral nasal obstruction associated with thick nasal secretions, anterior and posterior nasal drip, snoring and diffuse nasal pain. The biopsy revealed inverted papilloma. RESULTS: CT Scan and RMI of paranasal sinuses showed a bilateral origin of the tumor with a triple involvement on the left side: middle turbinate axilla, frontal recess posterior wall and ethmoidal sinus roof. Nasal endoscopic surgery approach was performed and the tumoral mass was removed completely. DISCUSSION: Inverted papilloma is an uncommon primary nasal tumor that presents three typical characteristics: a high rate of recurrence, local aggressive behaviour and association with malignancy. Although bilaterality is very rare, in this case the neoplasia occupied both nasal cavities with extension to left frontal, sphenoid and ethmoid sinuses. CONCLUSION: The authors, in line with the literature, showed that endoscopic approach represents once again a safe and efficient technique, even for larger tumors. KEY WORDS: Bilateral origin, Inverted papilloma, Paranasal sinuses.

Inverted papilloma and nasal polyp classification using a deep convolutional network integrated with an attention mechanism.

BACKGROUND: Inverted papilloma (IP) is a common sinus neoplasm with a probability of malignant transformation. Nasal polyps (NP) are the most frequent masses in the sinus. The classification of IP and NP using computed tomography (CT) is highly significant for preoperative recognition, treatment, and clinical examination. Few visible differences exist between IP and NP in CT, making it a challenge for otolaryngologists to distinguish between them. This study intended to classify IP and NP using a neural network and analyze its ability to discriminate the differences. METHODS: IP and NP in CT were classified using a deep convolutional neural network (CNN) with an attention mechanism, which combines a densely connected convolutional network (DenseNet) and squeeze-and-excitation network (SENet). Using SENet's channel attention, the specific channel weights in the feature maps are improved, which can enhance feature discriminativeness. To discuss the interpretability of SE-DenseNet, we analyzed the heatmap of the final convolutional layer. RESULTS: We evaluated the classification performance of SE-DenseNet on a clinical dataset containing 3382 slices for 136 patients. The experimental results and a heatmap show that SE-DenseNet can effectively locate sinonasal lesions in patients and distinguish IP from NP with an average Acc of 88.4% and AUC of 0.87. CONCLUSION: Otolaryngologists can use the proposed model to diagnose IP and NP in CT because of its accuracy and efficiency. Moreover, the visualized heatmaps produced by the convolutional layers show that the method is reliable.

Retrospective analysis of the risk of neoplasia associated with unilateral maxillary sinus opacification on computed tomography.

BACKGROUND: Unilateral maxillary sinus opacification on computed tomography may reflect an inflammatory or neoplastic process. The neoplasia risk is not clear in the literature. METHODS: In this retrospective study, computed tomography sinus scans performed over 12 months were screened for unilateral maxillary sinus opacification, and the rates of inflammatory and neoplastic diagnoses were calculated. RESULTS: Of 641 computed tomography sinus scans, the rate of unilateral maxillary sinus opacification was 9 per cent. Fifty-two cases were analysed. The risk of neoplasia was 2 per cent (inverted papilloma, n = 1). No cases of unilateral maxillary sinus opacification represented malignancy, but one case of lymphoma had an incidental finding of unilateral maxillary sinus opacification on the contralateral side. Patients with an antrochoanal polyp (n = 3), fungal disease (n = 1), inverted papilloma and lymphoma all had a unilateral nasal mass. CONCLUSION: Our neoplasia rate of 2 per cent was lower than previously reported. A unilateral mass was predictive of pathology that required operative management. Clinical findings, rather than simple findings of opacification on computed tomography, should drive the decision to perform biopsy.

Dynamic contrast-enhanced MRI can quantitatively identify malignant transformation of sinonasal inverted papilloma.

OBJECTIVE: To investigate the diagnostic performance of quantitative and semi-quantitative parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) in differentiating sinonasal inverted papilloma (SIP) from SIP with coexisting malignant transformation into squamous cell carcinoma (MT-SIP). METHODS: This retrospective study included 122 patients with 88 SIP and 34 MT-SIP. Quantitative and semi-quantitative parameters derived from DCE-MRI were compared between SIP and MT-SIP. The multivariate logistic regression analysis was performed to identify independent indicators and construct regression model for distinguishing MT-SIP and SIP. Diagnostic performance of independent indicators and regression model were evaluated using receiver operating coefficient (ROC) analysis and compared using DeLong test. RESULTS: There were significant differences in maximum slope of increase, contrast-enhancement ratio, bolus arrival time, volume of extravascular extracellular space (Ve), and rate constant (Kep) between SIP and MT-SIP (p < 0.05). There were no significant differences in initial area under the gadolinium curve (p = 0.174) and volume transfer constant (p = 0.105) between two groups. Multivariate analysis results showed that Ve and Kep were identified as the independent indicators for differentiating MT-SIP from SIP (p < 0.001). Areas under the ROC curves (AUCs) for predicting MT-SIP were 0.779 for Ve and 0.766 for Kep. The AUC of the combination of Ve and Kep was 0.831, yielding 83% specificity and 76.5% sensitivity. CONCLUSION: DCE-MRI can quantitatively differentiate between MT-SIP and SIP. The combination of Ve and Kep yielded an optimal performance for discriminating SIP from its malignant mimics. ADVANCES IN KNOWLEDGE: DCE-MRI with quantitative and semi-quantitative parameters can provide valuable evidences for quantitatively identifying MT-SIP.

Recurrent Primary Inverted Papilloma of the Mastoid with Intracranial Invasion: A 7-Year Follow-Up.

A 55-year-old man presented to the otolaryngology department complaining of aural fullness in his left ear after an episode of probable otitis 3 months before. magnetic resonance imaging revealed a soft tissue mass within the mastoid cavity that had destroyed the posterior wall of the middle ear with no apparent middle ear or sinonasal origin. The patient underwent a left canal wall-up tympanomastoidectomy, and the pathology report confirmed an inverted papilloma. Inverted papillomas are uncommon benign epithelial tumors related to a high recurrence rate and high risk of secondary malignant transformation after multiple surgeries. The patient has undergone 2 additional surgical interventions involving the neurosurgery team due to recurrent inverted papilloma that exerted a mass effect over the left cerebellar hemisphere. Despite no signs of recurrence on magnetic resonance imaging 5 years after the last surgery, at least 1 radiologic study per year is granted. Clinical multidisciplinary follow-up including nasal endoscopy and head and neck examination as a part of a stringent follow-up is essential to rule out synchronous nasosinusal inverted papillomas.

Classification staging systems on clinical and radiographic features of inverted sinonasal papilloma: A case report.

Inverted sinonasal papilloma is an infrequent tumor that mostly affects the elder group of 40-50 yr. This tumor is distinguished from other sinonasal tumors by three characteristics: a high rate of recurrence, carcinomatous changes, and a high potential for local destruction. In 40% of cases of inverted sinonasal papilloma showed an association with the human papillomavirus and considered as the main etiological agent. Here, we present a case of a 36-year-old male presented with pus discharge from the right upper back teeth region in the past 1 year. Correlating with clinical, radiographical features, a diagnosis of the Inverted sinonasal papilloma.

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.

Fluorescence grid analysis for the evaluation of piecemeal surgery in sinonasal inverted papilloma: a proof-of-concept study.

PURPOSE: Local recurrence occurs in ~ 19% of sinonasal inverted papilloma (SNIP) surgeries and is strongly associated with incomplete resection. During surgery, it is technically challenging to visualize and resect all SNIP tissue in this anatomically complex area. Proteins that are overexpressed in SNIP, such as vascular endothelial growth factor (VEGF), may serve as a target for fluorescence molecular imaging to guide surgical removal of SNIP. A proof-of-concept study was performed to investigate if the VEGF-targeted near-infrared fluorescent tracer bevacizumab-800CW specifically localizes in SNIP and whether it could be used as a clinical tool to guide SNIP surgery. METHODS: In five patients diagnosed with SNIP, 10 mg of bevacizumab-800CW was intravenously administered 3 days prior to surgery. Fluorescence molecular imaging was performed in vivo during surgery and ex vivo during the processing of the surgical specimen. Fluorescence signals were correlated with final histopathology and VEGF-A immunohistochemistry. We introduced a fluorescence grid analysis to assess the fluorescence signal in individual tissue fragments, due to the nature of the surgical procedure (i.e., piecemeal resection) allowing the detection of small SNIP residues and location of the tracer ex vivo. RESULTS: In all patients, fluorescence signal was detected in vivo during endoscopic SNIP surgery. Using ex vivo fluorescence grid analysis, we were able to correlate bevacizumab-800CW fluorescence of individual tissue fragments with final histopathology. Fluorescence grid analysis showed substantial variability in mean fluorescence intensity (FImean), with SNIP tissue showing a median FImean of 77.54 (IQR 50.47-112.30) compared to 35.99 (IQR 21.48-57.81) in uninvolved tissue (p < 0.0001), although the diagnostic ability was limited with an area under the curve of 0.78. CONCLUSIONS: A fluorescence grid analysis could serve as a valid method to evaluate fluorescence molecular imaging in piecemeal surgeries. As such, although substantial differences were observed in fluorescence intensities, VEGF-A may not be the ideal target for SNIP surgery. TRIAL REGISTRATION: NCT03925285.

A Rare Cause of SCC Antigen Elevation: Inverted Sinonasal Papilloma.

ABSTRACT: We report the case of a 68-year-old woman who underwent 18F-FDG PET/CT for squamous cell carcinoma antigen (SCC Ag) elevation in the follow-up of a uterine cervical cancer. The examination showed an FDG-avid mass of the left nasal cavity with left maxillary sinusitis and no other site of abnormal FDG uptake. Surgical resection of the nasal polyp was performed, and pathological examination of the specimen revealed an inverted sinonasal papilloma. SCC Ag returned to normal after surgery. Inverted sinonasal papilloma is a rare cause of SCC Ag elevation, which can be depicted by 18F-FDG PET/CT.