Sinonasal small round blue cell tumors: An approach to diagnosis

Top IHC/ISH Hacks for and Molecular Surrogates of Poorly Differentiated Sinonasal Small Round Cell Tumors

BACKGROUND

Poorly differentiated sinonasal small round cell tumors (SRCTs) are rare and heterogeneous, posing challenges in diagnosis and treatment.

METHODS

Recent advances in molecular findings and diagnostic refinement have promoted better understanding and management of these tumors.

RESULTS

The newly defined and emerging sinonasal entities demonstrate diverse morphologies, specific genomic signatures, and clinical behavior from conventional counterparts. In this review of SRCTs, emphasis is placed on the diagnostic approach with the employment of a pertinent panel of immunohistochemistry studies and/or molecular tests, fine-tuned to the latest WHO 5 classification of sinonasal/paranasal tumors and personalized treatment.

CONCLUSION

Specifically, this review focuses on tumors with epithelial and neuroectodermal derivation.

Aggressive primary sinonasal Ewing sarcoma with intraorbital and intracranial extension

Ewing sarcoma (ES) of the extraskeletal form is a rare occurrence and even rarer to manifest in the sinonasal tract. We describe a case of an advanced sinonasal ES with orbital and intracranial extension that was managed with chemotherapy and endoscopic surgery. Despite completing chemotherapy and surgical resection, the tumor progressed rapidly even before postoperative radiotherapy, and subsequently, she succumbed to death due to sepsis. We would like to discuss the management challenges, pitfalls, and surgical approach which may improve the outcome of this complicated disease.

Molecular Biomarkers in Sinonasal Cancers: New Frontiers in Diagnosis and Treatment

Purpose of Review

Sinonasal tumors are rare and heterogeneous diseases which pose challenges in diagnosis and treatment. Despite significant progress made in surgical, oncological, and radiotherapy fields, their prognosis still remains poor. Therefore, alternative strategies should be studied in order to refine diagnosis and improve patient care.

Recent Findings

In recent years, in-depth molecular studies have identified new biological markers, such as genetic abnormalities and epigenetic variations, which have allowed to refine diagnosis and predict prognosis. As a consequence, new histological entities have been described and specific subgroup stratifications within the well-known histotypes have been made possible. These discoveries have expanded indications for immunotherapy and targeted therapies in order to reduce tumor spread, thus representing a valuable implementation of standard treatments.

Summary

Recent findings in molecular biology have paved the way for better understanding and managing such rare and aggressive tumors. Although further efforts need to be made in this direction, expectations are promising.

Machine learning to differentiate small round cell malignant tumors and non-small round cell malignant tumors of the nasal and paranasal sinuses using apparent diffusion coefficient values

OBJECTIVE

We used radiomics feature-based machine learning classifiers of apparent diffusion coefficient (ADC) maps to differentiate small round cell malignant tumors (SRCMTs) and non-SRCMTs of the nasal and paranasal sinuses.

MATERIALS

A total of 267 features were extracted from each region of interest (ROI). Datasets were randomized into two sets, a training set (∼70%) and a test set (∼30%). We performed dimensional reductions using the Pearson correlation coefficient and feature selection analyses (analysis of variance [ANOVA], relief, recursive feature elimination [RFE]) and classifications using 10 machine learning classifiers. Results were evaluated with a leave-one-out cross-validation analysis.

RESULTS

We compared the AUC for all the pipelines in the validation dataset using FeAture Explorer (FAE) software. The pipeline using RFE feature selection and Gaussian process classifier yielded the highest AUCs with ten features. When the "one-standard error" rule was used, FAE produced a simpler model with eight features, including Perc.01%, Perc.10%, Perc.90%, Perc.99%, S(1,0) SumAverg, S(5,5) AngScMom, S(5,5) Correlat, and WavEnLH_s-2. The AUCs of the training, validation, and test datasets achieved 0.995, 0.902, and 0.710, respectively. For ANOVA, the pipeline with the auto-encoder classifier yielded the highest AUC using only one feature, Perc.10% (training/validation/test datasets: 0.886/0.895/0.809, respectively). For the relief, the AUCs of the training, validation, and test datasets that used the LRLasso classifier using five features (Perc.01%, Perc.10%, S(4,4) Correlat, S(5,0) SumAverg, S(5,0) Contrast) were 0.892, 0.886, and 0.787, respectively. Compared with the RFE and relief, the results of all algorithms of ANOVA feature selection were more stable with the AUC values higher than 0.800.

CONCLUSIONS

We demonstrated the feasibility of combining artificial intelligence with the radiomics from ADC values in the differential diagnosis of SRCMTs and non-SRCMTs and the potential of this non-invasive approach for clinical applications.

KEY POINTS

• The parameter with the best diagnostic performance in differentiating SRCMTs from non-SRCMTs was the Perc.10% ADC value. • Results of all the algorithms of ANOVA feature selection were more stable and the AUCs were higher than 0.800, as compared with RFE and relief. • The pipeline using RFE feature selection and Gaussian process classifier yielded the highest AUC.

Texture Analysis of Fat-Suppressed T2-Weighted Magnetic Resonance Imaging and Use of Machine Learning to Discriminate Nasal and Paranasal Sinus Small Round Malignant Cell Tumors

Objective

We used texture analysis and machine learning (ML) to classify small round cell malignant tumors (SRCMTs) and Non-SRCMTs of nasal and paranasal sinus on fat-suppressed T2 weighted imaging (Fs-T2WI).

Materials

Preoperative MRI scans of 164 patients from 1 January 2018 to 1 January 2021 diagnosed with SRCMTs and Non-SRCMTs were included in this study. A total of 271 features were extracted from each regions of interest. Datasets were randomly divided into two sets, including a training set (∼70%) and a test set (∼30%). The Pearson correlation coefficient (PCC) and principal component analysis (PCA) methods were performed to reduce dimensions, and the Analysis of Variance (ANOVA), Kruskal-Wallis (KW), and Recursive Feature Elimination (RFE) and Relief were performed for feature selections. Classifications were performed using 10 ML classifiers. Results were evaluated using a leave one out cross-validation analysis.

Results

We compared the AUC of all pipelines on the validation dataset with FeAture Explorer (FAE) software. The pipeline using a PCC dimension reduction, relief feature selection, and gaussian process (GP) classifier yielded the highest area under the curve (AUC) using 15 features. When the “one-standard error” rule was used, FAE also produced a simpler model with 13 features, including S(5,-5)SumAverg, S(3,0)InvDfMom, Skewness, WavEnHL_s-3, Horzl_GlevNonU, Horzl_RLNonUni, 135dr_GlevNonU, WavEnLL_s-3, Teta4, Teta2, S(5,5)DifVarnc, Perc.01%, and WavEnLH_s-2. The AUCs of the training/validation/test datasets were 1.000/0.965/0.979, and the accuracies, sensitivities, and specificities were 0.890, 0.880, and 0.920, respectively. The best algorithm was GP whose AUCs of the training/validation/test datasets by the two-dimensional reduction methods and four feature selection methods were greater than approximately 0.800. Especially, the AUCs of different datasets were greater than approximately 0.900 using the PCC, RFE/Relief, and GP algorithms.

Conclusions

We demonstrated the feasibility of combining artificial intelligence and the radiomics from Fs-T2WI to differentially diagnose SRCMTs and Non-SRCMTs. This non-invasive approach could be very promising in clinical oncology.

Diffusion Kurtosis Imaging and Intravoxel Incoherent Motion in Differentiating Nasal Malignancies

OBJECTIVES/HYPOTHESIS

To evaluate the usefulness of diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) in the differentiation of sinonasal malignant tumors (SNMTs) with different histological types.

STUDY DESIGN

Retrospective observational and diagnostic study.

METHODS

Sixty-five patients with SNMTs who underwent DKI and IVIM were enrolled in this retrospective study, including 27 squamous cell carcinomas (SCCs), 13 olfactory neuroblastomas (ONBs), 14 malignant melanomas (MMs) and 11 lymphomas. The kurtosis (K) and diffusion coefficient (Dk) from DKI and the pure diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (f), and the product of D* and f (f∙D*) from IVIM were measured. Kruskal-Wallis and Dunn multiple comparison tests with Bonferroni correction, receiver operating characteristic curve, and logistic regression analyses were used for statistical analysis.

RESULTS

Lymphomas demonstrated the highest K values but lowest Dk, D, D*, f, and f∙D* values among these four malignant tumors. ONBs exhibited high K values and MMs had highest D*, f, and f∙D* values. The cutoff value of ≤0.887 × 10^-3 mm² /sec for f∙D* provided a sensitivity, specificity, and an accuracy of 100%, 98.1%, and 98.5%, respectively, for differentiating lymphomas from the other three entities. The combination of f∙D* and D values showed a sensitivity of 92.9% and a specificity of 92.5% for the discrimination of MMs from ONBs and SCCs. The K value was useful for differentiating ONBs from SCCs, with a threshold value of 0.942 (sensitivity, 84.6%; specificity, 63.0%).

CONCLUSIONS

The combined use of DKI and IVIM is helpful for differentiating among four histological types of SNMTs.

LEVEL OF EVIDENCE

3 Laryngoscope, 2019.

Positron emission computed tomography and magnetic resonance imaging features of sinonasal small round blue cell tumors

AIM

The sinonasal tract hosts numerous types of undifferentiated neoplasms, having small round cell morphology. The aim of this study was to determine whether sinonasal small round blue cell tumors (SRBCT) have distinct imaging features on computed tomography (CT), magnetic resonance imaging (MRI), and 18-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT.

METHODS

Seventy-three patients (43 male; M_age = 61.2 years) with histopathologically proven sinonasal SRBCT were retrospectively reviewed. Imaging features of SRBCTs including location, maximum dimension, margin characteristics, presence of calcification, sclerotic bone changes, intratumoral necrosis, tumor extension, bone destruction, bone remodeling, perineural spread, T1- and T2-weighted MRI signal intensity, qualitative features on diffusion-weighted imaging and ¹⁸F-FDG PET/CT, and pattern of contrast enhancement were analyzed using Fisher's exact test or the chi-square test. The maximum standardized uptake values (SUV_max) and apparent diffusion coefficient (ADC_mean) values of SRBCT were compared by utilizing the Kruskal-Wallis test.

RESULTS

There was a significant difference between SRBCT type regarding the tumor location (p = 0.006), ¹⁸F-FDG uptake pattern (p = 0.006), involvement of the orbit (p = 0.016) and pterygopalatine fossa (p = 0.043), the presence of perineural spread (p < 0.001), bone destruction (p = 0.034), and intratumoral necrosis (p = 0.022). Bone destruction and necrosis were more common in rhabdomyosarcoma. Perineural spread was common in sinonasal adenoid cystic carcinoma (ACC). Qualitative ¹⁸F-FDG uptake features as well as tumor location were significantly different between sinonasal ACC and sinonasal undifferentiated carcinoma. The ADC_mean and SUV_max values were not statistically different between SRBCT types.

CONCLUSIONS

Sinonasal SRBCTs have numerous distinct imaging features on CT, MRI, and ¹⁸F-FDG PET/CT that could be useful in the differentiation between lesions when the histopathologic diagnosis is inconclusive.

Ewing's sarcoma of the sinonasal tract with orbital extension: a rare case report and literature review

Ewing’s sarcoma is a rare and aggressive tumor which classified as peripheral primitive neuroectodermal tumor. It commonly arises in the long bones of the extremities and rarely in the head and neck region. Localization of the sinonasal tract is a rare occurrence thus the number of clinical studies published in the literature are limited. The diagnosis of this tumor requires a histopathological examination, immunohistochemistry and cytogenetic analysis. Ewing’s sarcomas are characterized by a CD99 positivity in immunohistochemistry stain and a t(11:22)(q24:q12) translocation in cytogenetic study. The treatment of choice is the multimodality treatment including surgery, radiotherapy and chemotherapy. This is a case report of sinonasal and orbital Ewing’s sarcoma in a 24-year-old male patient who presented with a history of right nasal obstruction, right eye pain and periorbital edema.

Sinonasal Ewing Sarcoma: A Case Report and Literature Review

INTRODUCTION

Ewing sarcoma (ES) of the sinonasal tract and associated primitive neuroectodermal tumors are rare. To our knowledge, only 10 case reports of sinonasal ES of the nose or paranasal sinuses have been reported. Furthermore, there has been only 1 case of sinonasal ES arising from the middle turbinate. Recommended management of sinonasal ES stems from the management of its osseous counterpart, ES, but treatment with surgery, radiotherapy, and chemotherapy is varied. Five-year survival rates vary from 21% to 70%, with the lower rates representing patients presenting with metastatic disease.

CASE PRESENTATION

A 26-year-old man presented with persistent left-sided nasal obstruction. Endoscopy demonstrated a friable mass in the left nasal cavity originating from the middle turbinate with extension into the nasopharynx, confirmed with computed tomography and magnetic resonance imaging. There was no evidence of metastatic disease on positron emission tomography-computed tomography. Histopathologic results were consistent with sinonasal ES. The result of fluorescent in situ hybridization was positive for the EWS gene translocation. A multidisciplinary tumor board evaluated the patient. The patient then underwent neoadjuvant chemotherapy, followed by definitive endoscopic surgical resection and postoperative radiotherapy.

DISCUSSION

Our literature review found more involvement of the maxillary and ethmoid sinuses compared with the nasal cavity, and that the role of radiation and surgical approach was varied. ES of the sinonasal tract is a rare entity with high mortality, but few standardized treatment protocols exist. Further study and evidence-based treatment protocols are needed. This article outlines the role of relevant imaging, a multidisciplinary team approach, and the optimal timing of surgery, chemotherapy, and radiation.

Intravoxel incoherent motion MRI for differentiating sinonasal small round cell malignant tumours (SRCMTs) from Non-SRCMTs: comparison and correlation with dynamic contrast-enhanced MRI

AIM

To investigate the value of intravoxel incoherent motion (IVIM) in the differentiation of sinonasal small round cell malignant tumours (SRCMTs) from non-SRCMTs and to compare and correlate these results with those of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Ninety patients with histologically confirmed sinonasal malignant tumours (53 SRCMTs and 37 non-SRCMTs) who underwent conventional MRI, IVIM, and DCE-MRI before treatment were enrolled. The IVIM and DCE-MRI parameters were measured. Statistical analyses were performed using Student's t-tests, receiver operating characteristic (ROC) curve analyses, and Spearman's correlation coefficients.

RESULTS

A lower pure diffusion coefficient (D) value and a higher pseudo-diffusion coefficient (D*) value were found in the sinonasal SRCMTs than in the non-SRCMTs (p<0.001 and p=0.011, respectively). Moreover, the mean extravascular extracellular space volume ratio (V_e) of the SRCMTs was significantly lower than that of the non-SRCMTs (p=0.020). ROC curve analysis showed that the diagnostic performance of D outperformed those of the other perfusion and diffusion parameters. A cut-off D value of 0.56 ×10^-3 mm²/s yielded a sensitivity of 80.4%, a specificity of 75%, and an accuracy of 78.2%, with an AUC of 0.825. Significant but poor-to-fair correlations were found between the parameters from IVIM and DCE-MRI.

CONCLUSIONS

The D and D* values of IVIM and the V_e value of DCE-MRI are helpful in distinguishing sinonasal SRCMTs from non-SRCMTs, with the D values having the best diagnostic efficiency.

Usefulness of NKX2.2 Immunohistochemistry for Distinguishing Ewing Sarcoma from Other Sinonasal Small Round Blue Cell Tumors

NKX2.2 is a new immunohistochemical marker that has been reported to be sensitive and specific for Ewing sarcoma (ES). It has not, however, been investigated specifically in the sinonasal small round blue cell tumor (SRBCT) differential diagnosis which includes many tumors specific to that site. It has also not been investigated in the newly recognized "adamantinoma-like" variant of ES. Immunohistochemistry for NKX2.2 was performed on 170 poorly differentiated sinonasal neoplasms: 73 squamous cell carcinomas (67 poorly differentiated, non-keratinizing, or basaloid types and 6 nasopharyngeal carcinomas), 46 olfactory neuroblastomas, 8 sinonasal undifferentiated carcinomas (SNUCs), 6 melanomas, 7 Ewing sarcomas, 6 SMARCB1-deficient carcinomas, 6 teratocarcinosarcomas, 5 alveolar rhabdomyosarcomas, 4 solid adenoid cystic carcinomas, 4 NK/T cell lymphomas, 3 NUT carcinomas, and 2 small cell carcinomas. NKX2.2 was positive in 7 of 7 (100%) Ewing sarcomas, including 3 adamantinoma-like variant (all diffuse, 5 strong and 2 weak). It was also positive in 5 of 6 (83%) teratocarcinosarcomas (strong, but focal), 12 of 46 (26%) olfactory neuroblastomas (diffuse, 2 strong and 10 weak), 4 of 6 melanomas (2 diffuse, 2 focal, all weak), and 1 of 2 small cell carcinomas (diffuse and strong). All squamous cell carcinomas, NUT carcinomas, SMARCB1-deficient carcinomas, SNUCs, solid adenoid cystic carcinomas, NK/T cell lymphomas, and alveolar rhabdomyosarcomas were negative. In the sinonasal SRBCT differential diagnosis, NKX2.2 is a useful and very sensitive marker for Ewing sarcoma, including the treacherous adamantinoma-like variant. At the same time, it is not entirely specific, as it will be positive in a subset of other neuroendocrine/neuroectodermal tumors. As a result, NKX2.2 must be utilized as part of an immunohistochemical panel with other markers, especially cytokeratins, melanoma markers, and CD99.

Updates on Immunohistochemical and Molecular Markers in Selected Head and Neck Diagnostic Problems

CONTEXT

- The head and neck regions have complex anatomic structures. They are not exempted from the rare occurrences of highly unusual, diagnostically challenging malignant neoplasms and mimickers.

OBJECTIVE

- To review and update the utility of immunohistochemistry and molecular biomarkers and to pursue diagnostic accuracy on selected rare neoplasms, especially some poorly differentiated malignancies.

DATA SOURCES

- Personal experience and information from the literature.

CONCLUSIONS

- Head and neck tumors include neoplasms originating from heterogeneous tissue. Using the selected clinical cases, this review illustrates a continuous development of emerging molecular-genetic techniques to assist in the interpretation of uncommon, often poorly differentiated, highly malignant neoplasms. The diagnostic results are appropriately transmitted to the oncologists, radiation oncologists, and surgeons to create a coordinated plan of care for patients with these unusual disorders affecting the head and neck.

SMARCA4-deficient Sinonasal Carcinoma

The term "sinonasal undifferentiated carcinoma (SNUC)" has been coined in 1986 for a highly aggressive sinonasal tract epithelial neoplasm showing distinctive morphology, but lacking any specific line of differentiation. Recent developments resulted in a dynamic splitting of new entities traditionally included in the spectrum of SNUC. Sinonasal NUT-midline carcinoma, adamantinoma-like Ewing family tumors and most recently, SMARCB1(INI1)-deficient sinonasal carcinoma are the main entities defined by specific genetic aberrations. To our knowledge, involvement of subunits of the SWItch/Sucrose Non-fermentable (SWI/SNF) chromatin remodeling complex other than SMARCB1 has not been implicated in the pathogenesis of SNUC-like neoplasms. We herein describe a 40-year-old woman who presented with a large infiltrative mass involving the right nasal cavity and the sinuses with extension into the skull base and periorbital tissue (cT4N2M0). Biopsies were interpreted initially as poorly differentiated neuroendocrine carcinoma followed by surgical resection and radiochemotherapy. No other extra-nasal tumor was detected on imaging. The patient was alive with disease at last follow-up (9 months from initial diagnosis). Histological evaluation showed poorly differentiated small round blue cell neoplasm with diffuse expression of pancytokeratin but not high molecular weight cytokeratin subsets, CK7, p63, S100, desmin or NUT. Neuroendocrine markers showed limited focal weak reactivity. SMARCB1, SMARCA2 and ARID1A were intact in the tumor cells but SMARCA4 was completely lost. This case highlights the rare occurrence of SMARCA4-deficiency in poorly differentiated sinonasal carcinomas and points to the importance of including other SWI/SNF complex subunits in the evaluation of SMARCB1-intact sinonasal malignancies.

Sinonasal Small Round Blue Cell Tumors: An Immunohistochemical Approach

Although clinical history and morphologic appearance should be the initial considerations when evaluating small round blue cell tumors of the sinonasal tract, the final diagnosis often hinges on immunohistochemical findings. Unfortunately, interpretation of stains in these tumors is fraught with numerous pitfalls and limitations. This article presents an approach to sinonasal small round blue cell tumors based on four common immunohistochemical patterns: cytokeratin positivity, squamous marker positivity, neuroendocrine marker positivity, and cytokeratin negativity.

Primary Ewing's sarcoma of the sinonasal tract in adults: A challenging disease

BACKGROUND

Sinonasal localization of Ewing's sarcoma in adults is an exceedingly rare event.

METHODS

The clinical records of 5 patients with primary sinonasal Ewing's sarcoma treated from 1992 to 2012 were retrospectively analyzed. All pathologic slides were reviewed by 2 experienced pathologists. All patients underwent multimodality treatments.

RESULTS

Median age was 36 years (range, 25-52 years). At referral, 2 patients had the original diagnosis changed by review of the histologic slides. Tumors were classified as T4aN0M0 (4 patients) and T2N0M0 (1 patient). Median follow-up was 110 months (range, 70-139 months). Only 1 patient, who started treatment elsewhere based on an incorrect histologic diagnosis, experienced multiple recurrences and eventually died of widespread metastasis.

CONCLUSION

Correct pathologic diagnosis can have a crucial impact on treatment planning and outcome. Multimodality therapy is the key for long-term successful results. Because of the rarity of the tumor, referral to highly experienced care centers is strongly recommended. © 2016 Wiley Periodicals, Inc. Head Neck 39: E45-E50, 2017.

Diagnosis and treatment of a rare sinonasal neuroendocrine tumour: adding to the evidence

Sinonasal neuroendocrine tumours (NETs) are rare, aggressive neoplasms with a high recurrence potential. There are no robust protocols for the management of these tumours. An 81-year-old man presented with an incidental sinonasal mass visualised on CT scan of head. Over the next few weeks he developed new onset, progressively worsening headache, right eye ptosis and restricted extraocular movements. Imaging confirmed a rapidly enlarging tumour involving the right nasal cavity and the orbit. Biopsy showed a large cell neuroendocrine carcinoma of the right ethmoidal sinus. The patient was treated with concurrent cisplatin chemotherapy and radiation. Repeat imaging showed decrease in tumour volume. The patient continues to do well and follows up regularly with our oncology service. Current protocols comprising chemotherapy after radiation are based on limited studies. A regimen involving concurrent chemoradiation also appears to aid in tumour volume reduction. Additional studies are required to formulate robust clinical protocols for management of sinonasal NETs.