Whole exome sequencing analysis of a rare biphasic Sinonasal sarcoma: Genetic insights and multidisciplinary approach in diagnosis and treatment

INTRODUCTION

Biphenotypic sinonasal sarcoma (BSNS) is a rare, low-grade malignant soft tissue sarcoma with myogenic and neurogenic differentiation. This case report integrates medical-imaging, pathology, and molecular genetics, contributing valuable insights into the diagnosis and management of BSNS.

CASE PRESENTATION

A 45-year-old female patient reported chronic nasal congestion and rhinorrhea. Imaging revealed a 31 × 26 mm low-density nasal mass, and pathology confirmed BSNS, characterized by spindle cells infiltrating the respiratory epithelium, positive for S-100 and α-SMA. The patient underwent endoscopic resection of the skull base lesion and Draf IIa surgery, with drainage of obstructive purulent secretions. The patient was monitored postoperatively and discharged with follow-up instructions, nasal irrigation, and topical steroids.

DISCUSSION

Whole-exome sequencing identified significant genetic alterations in PAX3, MAML3, NCOA1, and FOXO1, shedding light on the molecular mechanisms of BSNS. This case underscores the importance of a multidisciplinary approach in diagnosing rare tumors and the potential of molecular genetics to guide treatment strategies.

CONCLUSION

This case emphasizes the critical role of molecular genetic analysis in diagnosing and treating biphasic sinonasal sarcoma. The identified tumor cell patterns and molecular markers provide novel insights into its pathogenesis and improve diagnostic precision, offering a foundation for future research.

Biphenotypic sinonasal sarcoma in a toddler: a case report and literature review

INTRODUCTION

Biphenotypic sinonasal sarcoma (BSNS) is an extremely rare malignant tumor characterized by neural and myogenic differentiation. No documented cases of BSNS have been reported in toddlers.

CASE REPORT

A 1-year-11-month-old girl presented with significant unilateral nasal bleeding. Identification of the bleeding source during the initial assessment was particularly challenging given the patient's agitated state. Subsequent exploration under anesthesia revealed an exophytic tumor arising from the middle turbinate. Afterwards, the patient underwent tumor excision via transnasal endoscopy, with no immediate complications. Immunohistochemistry confirmed a diagnosis of BSNS. No signs of recurrence or distant metastasis were observed over a two-year follow-up period.

CONCLUSION

Massive, persistent nasal bleeding due to sinonasal malignancies in very young children is exceedingly uncommon. For young patients with recurrent or atypical epistaxis, clinicians should consider a neoplastic origin, given the difficulty in pinpointing the bleeding source. This case aims to remind physicians to include such rare malignancies in differential diagnoses, stressing the need for heightened awareness during pediatric assessments.

Biphenotypic Sinonasal Sarcoma: Literature Review of a Peculiar Pathological Entity-The Neurosurgical Point of View

BACKGROUND

Biphenotypic sinonasal sarcoma (BSNS) is a low-grade tumor of the sinonasal tract with frequent extension to the orbit and skull base. Due to its rare incidence and recent histopathological and molecular characterization, little data are available in regard to its natural history, treatment and surveillance protocol.

METHODS

A comprehensive literature review in Embase online electronic databases on BSNS was made. The analyzed factors included the patients' sex and age, presenting symptoms and signs, anatomical origin and pattern of growth of the tumor, immunohistochemical and molecular features, time to treatment, type of treatment, surgical approach, extent of resection, peri- and post-operative complications, adjuvant therapies, clinical outcome, recurrence and overall survival rates.

RESULTS

This literature review involved 34 studies for an overall series of 149 cases of BSNS. The female (66.9%) and middle-aged populations (median 54.88 years old) were mainly affected. The most frequent clinical onset was nasal obstruction (81%), followed by facial discomfort (44%), epistaxis (15.5%) and ocular impairment (14.3%). Ethmoid sinus (67.8%) and nasal cavity (45.4%) were the most common anatomical site of tumor origin, while an extension to the orbit and skull base was registered in 28.7% and 24.5% of cases. Surgery was the main treatment, especially in the form of endoscopic endonasal approach (56.9%), and allowed for gross total resection in 79% of cases. The recurrence rate was 26.2%; three cases of tumor-related death were reported. Median follow-up was 4.6 years.

CONCLUSIONS

Biphenotypic sinonasal sarcoma is a rare and unique tumoral entity in terms of biological and clinical behavior. Based on the current knowledge, surgery plays the leading role in treatment, accounting for gross total tumor resection in most cases, allowing for clinical symptom and sign resolution and presenting a low rate of perioperative complications. The type of approach and the aim of surgery should be assessed case by case according to patient and pathology features and the surgeon's experience, as well as the aim of the treatment. Further studies including large surgical series and with long follow-up are required to define prognostic factors and guidelines of treatment for this peculiar pathological entity.

Mesenchymal Tumors of the Head and Neck

The majority of neoplasms of the head and neck are of epithelial origin primarily including mucosal squamous cell neoplasms (papillomas; squamous cell carcinoma) as well as salivary gland neoplasms. However, the full spectrum of mesenchymal neoplasms (benign and malignant) typically arising in soft tissue sites may also develop in superficial layers of the upper aerodigestive tract. The diversity of mesenchymal neoplasms arising in the head and neck is beyond the scope of this article, and our focus will be on some of the more common and/or diagnostic problematic mesenchymal tumors occurring in the sinonasal tract, oral cavity/odontogenic, pharynx, larynx, and neck.

Biphenotypic Sinonasal Sarcoma with Orbital Invasion: A Literature Review and Modular System of Surgical Approaches

Background: Biphenotypic sinonasal sarcoma is a rare low-grade tumor arising from the sinonasal tract, featuring locally aggressive biological behavior, with a tendency to invade the orbit and skull base. There are no defined guidelines of treatment; thus, the management varies among different institutions. The aim of the present study is to provide a modular system of surgical approaches according to the lesion pattern of growth from a literature review. Materials and Methods: A comprehensive and detailed literature review on the PubMed and Embase online electronic databases on biphenotypic sinonasal sarcoma with orbital invasion was conducted. A personal case exhibiting peculiar features was also added. Demographic (patient's sex and age), clinical (presenting symptoms and time to treatment), neuroradiological (anatomical origin and pattern of growth), and treatment (type of treatment, surgical approach, extent of resection, peri- and postoperative complications, and adjuvant therapies) data, as well as clinical outcome, recurrence rates, and overall survival, were analyzed. Results: Thirty-one patients harboring biphenotypic sinonasal sarcoma with orbital invasion were identified. Tumors mainly affected female patients (66.7%) and a middle-aged population (median 55.2 years old). Simultaneous skull base involvement occurred in most cases (80.6%). Surgery was performed in all but one case (97%), as unique treatment (59%) or in association with radio-(23.5%) and/or chemotherapy (5.9%/2.9%), allowing for gross total tumor resection in most cases (66.7%). The endoscopic endonasal approach was the most adopted surgical corridor (51.7%). The local recurrence rate was 19.3%, and only two cases of tumor-related mortality occurred. Conclusions: Surgery is the only curative treatment, with the main goal to restore/improve/arrest progression of clinical manifestations. The endoscopic endonasal route represents the master approach for lesions confined to the midline. Microsurgical transcranial and endoscopic transorbital approaches have a complementary role for addressing the lesion's component with large intracranial extension or affecting the paramedian aspect of the anterior cranial fossa and superior-lateral orbital compartment, respectively. The approach selection should be made case by case according to the tumor pattern of growth.

Biphenotypic Sinonasal Sarcoma With High-Grade Features: A Diagnostic Challenge

Biphenotypic sinonasal sarcoma (BSNS) is a rare neoplasm of the sinonasal tract. These tumors show neural and myogenic differentiation and are characterized by PAX3 translocations. The immunophenotypic features reflect their dual differentiation. They are low-grade sarcomas that show monomorphic spindle cells in sheets, fascicles, and herringbone patterns and are positive for S100 and smooth muscle actin. These tumors are common in elderly female patients and have a locally aggressive course. High-grade presentation or transformation was not documented until recently. Total 3 BSNSs have now been documented in the literature and we report a fourth tumor with high-grade transformation 8 years after the initial presentation. We identify the morphologic and immunohistochemical features of the high-grade areas and we highlight the stark differences with the low-grade areas based on literature and our specimen. We also discuss the diagnostic challenges that may come up with such a presentation.

Integrated Molecular and Histological Insights for Targeted Therapies in Mesenchymal Sinonasal Tract Tumors

PURPOSE OF REVIEW

This review aims to provide a comprehensive overview of mesenchymal sinonasal tract tumors (STTs), a distinct subset of STTs. Despite their rarity, mesenchymal STTs represent a unique clinical challenge, characterized by their rarity, often slow progression, and frequently subtle or overlooked symptoms. The complex anatomy of the sinonasal area, which includes critical structures such as the orbit, brain, and cranial nerves, further complicates surgical treatment options. This underscores an urgent need for more advanced and specialized therapeutic approaches.

RECENT FINDINGS

Advancements in molecular diagnostics, particularly in next-generation sequencing, have significantly enhanced our understanding of STTs. Consequently, the World Health Organization has updated its tumor classification to better reflect the distinct histological and molecular profiles of these tumors, as well as to categorize mesenchymal STTs with greater accuracy. The growing understanding of the molecular characteristics of mesenchymal STTs opens new possibilities for targeted therapeutic interventions, marking a significant shift in treatment paradigms. This review article concentrates on mesenchymal STTs, specifically addressing sinonasal tract angiofibroma, sinonasal glomangiopericytoma, biphenotypic sinonasal sarcoma, and skull base chordoma. These entities are marked by unique histopathological and molecular features, which challenge conventional treatment approaches and simultaneously open avenues for novel targeted therapies. Our discussion is geared towards delineating the molecular underpinnings of mesenchymal STTs, with the objective of enhancing therapeutic strategies and addressing the existing shortcomings in the management of these intricate tumors.

A Minimally Invasive Endoscopic Transnasal and Transorbital Approach to Sinonasal Tumor Resection

A 35-year-old female with an extensive biphenotypic sinonasal sarcoma (BSNS) eroding through the left frontal sinus into the orbit required gross total resection of the tumor. We wanted to forgo an open approach and provide a less invasive alternative via combined endonasal and transorbital endoscopic techniques to allow for tumor removal through small, well-disguised incisions. We utilized three portals-nasal, transorbital, and anterior table window-to create interconnected orbit-sinonasal corridors, thus generating alternate pathways for visualization and manipulation of this extensive tumor. Laryngoscope, 134:1308-1312, 2024.

Spindle Cell Tumors of the Sinonasal Tract: A Diagnostic Update with Focus on Ancillary Workup

Spindle cell neoplasms arising in the head and neck may be challenging to recognize due to their relative rarity. While underlying molecular alterations are increasingly elucidated, testing for these features may not be readily available. In most cases, combinations of key morphologic features and diagnostic immunohistochemical markers can be used to replace molecular diagnostics. Conversely, some molecular alterations and expression of their surrogate biomarkers are not specific for any one entity, and it is important to recognize these to avoid diagnostic pitfalls. In this review, we discuss both old and new spindle cell tumors of the sinonasal tract, with an emphasis on histologic features and clinically relevant immunohistochemical markers serving as surrogate markers for underlying genomic alterations.

Biphenotypic Sinonasal Sarcoma with Orbital and Skull Base Involvement Report of 3 Cases and Systematic Review of the Literature

Biphenotypic sinonasal sarcoma (BSNS) is a rare malignant tumour of the upper nasal cavity and ethmoid sinuses that presents predominantly in middle aged female patients and show a characteristic infiltrative and hypercellular proliferation of spindle cells that demonstrate a specific immunoreactivity. We present three cases with BSNS that had different presenting complaints, either sinonasal or orbital problems, underwent endoscopic surgical treatment and/or radiotherapy and have been disease free on long follow up. A systematic review of all published cases was performed to identify all BSNS cases known at present. BSNS requires prompt and correct diagnosis with accurate surgical resection as well as consideration of radiotherapy. Our three cases confirm the findings of the literature and support that BSNS is an aggressive but treatable malignant disease of the sinonasal tract.

Biphenotypic Sinonasal Sarcoma: A Genetically Confirmed Case Showing Bone Invasion Accompanying a Non-neoplastic Respiratory Epithelium

Biphenotypic sinonasal sarcoma is a newly established tumor entity that is associated with distinct clinicopathological findings. Biphenotypic sinonasal sarcoma is a rare, low-grade spindle cell sarcoma that arises in middle-aged females, exclusively in the sinonasal tract. A fusion gene involving PAX3 is detected in most biphenotypic sinonasal sarcomas, which aids in its diagnosis. Here, we report a case of biphenotypic sinonasal sarcoma with its cytological findings. The patient was a 73-year-old woman who presented with purulent nasal discharge and dull pain in the left cheek area. Computed tomography showed a mass extending from the left nasal cavity to the left ethmoid sinus, the left frontal sinus, and the frontal skull base. She underwent a combined transcranial and endoscopic approach for en bloc resection with a safety margin. Histologically, spindle-shaped tumor cells have been thought to proliferate mainly in the subepithelial stroma. Here, nasal mucosal epithelial hyperplasia was noted, and the tumor had invaded the bone tissue accompanying the epithelial cells. Fluorescence in situ hybridization (FISH) analysis showed a PAX3 rearrangement, and next-generation sequencing identified a PAX3::MAML3 fusion. Based on FISH, split signals were observed not in respiratory cells but in stromal cells. This indicated that respiratory cells were non-neoplastic. In the diagnosis of biphenotypic sinonasal sarcoma, the inverted growth of the respiratory epithelium can be a diagnostic pitfall. FISH analysis using a PAX3 break-apart probe is helpful not only for an accurate diagnosis but also for detecting the true neoplastic cells.

Novel PAX3::INO80D Fusion in Biphenotypic Sinonasal Sarcoma in an Adult

This case report describes a novel gene fusion of PAX3::INO80D in a biphenotypic sinonasal carcinoma in a woman in her 40s.

Biphenotypic Sinonasal Sarcoma with a Novel PAX7::PPARGC1 Fusion: Expanding the Spectrum of Gene Fusions Beyond the PAX3 Gene

Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade malignancy occurring in the sinonasal tract that is characterized by dual neural and myogenic differentiation. Rearrangements involving the PAX3 gene, usually with MAML3, are a hallmark of this tumor type and their identification are useful for diagnosis. Rarely, a MAML3 rearrangement without associated PAX3 rearrangement has been described. Other gene fusions have not been previously reported. Herein, we report a 22 year-old woman with a BSNS harboring a novel gene fusion involving the PAX7 gene (specifically PAX7::PPARGC1A), which is a paralogue of PAX3. The histologic features of the tumor were typical with two exceptions: a lack of entrapment of surface respiratory mucosa and no hemangiopericytoma-like vasculature. Immunophenotypically, the tumor was notably negative for smooth muscle actin, which is usually positive in BSNS. However, the classic S100 protein-positive, SOX10-negative staining pattern was present. In addition, the tumor was positive for desmin and MyoD1 but negative for myogenin, a pattern that is common among BSNS with variant fusions. Awareness of the possibility of PAX7 gene fusions in BSNS is important as it may aid in the diagnosis of PAX3 fusion negative tumors.

Diagnosis and Treatment of Rare Adult Embryonal Rhabdomyosarcoma in Maxillary Sinus

OBJECTIVE

To investigate the clinicopathological features, imaging features, diagnosis, and prognosis of embryonal rhabdomyosarcoma (ERMS) in the maxillary sinus.

METHODS

The detailed clinical data of rare patients with embryonal ERMS of maxillary sinus admitted to our hospital were retrospectively analyzed, and the embryonal ERMS was confirmed by pathological examination and immunohistochemistry, and the relevant literature was reviewed.

RESULTS

A 58-year-old man was admitted to the hospital with the chief complaint of "numbness and swelling of the left cheek for 1 and a half months". Blood routine, biochemistry, paranasal sinus computed tomography, and magnetic resonance imaging were performed after admission, and the pathology showed ERMS. At present, it is generally in good condition. Pathological examination showed that the cells were all small and round. Immunohistochemistry showed Desmin (+) and Ki-67 (+70%).

CONCLUSION

The early symptoms of ERMS of the maxillary sinus are atypical and diverse, with a high degree of malignancy, rapid progression, strong invasiveness, and poor prognosis. Early diagnosis and treatment should be based on clinical characteristics, imaging examination, and immunohistochemical results.

Biphenotypic sinonasal sarcoma with PAX3::MAML3 fusion transforming into high-grade rhabdomyosarcoma: report of an emerging rare phenomenon

We report a case of a 67-year-old male patient with a sinonasal tumor that showed areas of classic biphenotypic sinonasal sarcoma (BSNS) which in some sections sharply transitioned into high-grade rhabdomyosarcoma. Immunohistochemically, the conventional BSNS parts showed S100 protein, SMA, PAX7, and focal MyoD1 expression, whereas desmin and myogenin were negative. In contrast, the cells in high-grade areas expressed desmin, MyoD1, myogenin, and PAX7, while being negative for S100 protein and SMA. Using the Archer FusionPlex assay, the classical PAX3::MAML3 gene fusion was detected. FISH for PAX3 and MAML3 confirmed a break of these genes in both components. Despite aggressive therapy, the tumor progression resulted in the patient's death. The herein presented case, together with 2 previously published cases of BSNS with high-grade transformation, helps to better understand this novel phenomenon. Although the risk for such transformation appears low, it has important clinical and diagnostic implications which are discussed.

Biphenotypic sinonasal sarcoma: European multicentre case-series and systematic literature review

Objective

Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade cancer that was included from the 4th edition of WHO classification of head and neck tumours. The purpose of this study is to analyse clinical behaviour, pattern of recurrences and survival outcomes of this neoplasm.

Methods

Retrospective review of patients affected by BSNS who were treated via an endoscopic-assisted approach in 6 European tertiary-care referral hospitals. Cases of BSNS described in literature since 2012 to date were fully reviewed, according to PRISMA guidelines.

Results

A total of 15 patients were included. Seven patients were treated via an endoscopic endonasal approach, 4 with endoscopic transnasal craniectomy, and 4 via a cranio-endoscopic approach. Adjuvant treatment was delivered in 2 cases. After a mean follow-up of 27.3 months, systemic metastasis was observed in 1 case; the 5-year overall survival and disease-free survival rates were 100% and 80 ± 17.9%, respectively.

Conclusions

BSNS is a locally aggressive tumour with a low recurrence rate and encouraging survival outcomes if properly treated with surgical resection and free margins followed by adjuvant radiotherapy for selected cases. Endoscopic-assisted surgery is safe and effective as an upfront treatment within a multidisciplinary care protocol.

Small Biopsy Samples: Are They Representative for Biphenotypic Sinonasal Sarcoma?

(1) Background: Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade neoplasm of the sinonasal tract. It is characterized by specific PAX3 gene rearrangements and both myogenic and neural differentiation. The purpose of the study was to describe the histologic, immunohistochemical and molecular features of BSNS and indicate important clues for small incisional biopsy diagnostics. (2) Methods: Archival samples from patients with nasal cavities or ethmoid sinuses tumors were searched for BSNS cases. Inclusion criteria were the presence of spindle cell morphology and low-grade appearance. Both biopsy and resection specimens were stained for identical IHC panels including, i.a., S100, SMA, SOX10 and PAX3. FISH for PAX3 and SS18 was performed on biopsy specimens. (3) Results: BSNS diagnosis was made in 6 cases included in the study and confirmed by PAX3 rearrangement by FISH in 5 specimens. The pattern of IHC expression was identical for paired biopsy and resection samples apart from one BSNS case. (4) Conclusions: Incisional biopsy seems to be a sufficient method to establish BSNS diagnosis in most cases. Characteristic morphological features together with S100, SOX10 and SMA as the screening markers are useful for confirming the diagnosis. In cases of divergent morphology and immunoprofile evaluation of PAX3 rearrangement is vital.

[Gene expression profiling in melanoma diagnostics: problems and future application in clinical practice]

Difficulties in the diagnosis and differential diagnosis of melanoma in the work of a pathologist include not only conflicting structural and morphological features, but also the insufficient effectiveness of biochemical and some molecular markers in immunohistochemical studies. The review presents modern alternative methods for diagnosing malignant tumors based on the assessment of gene expression, the performance, objectivity and reliability of the determination of which may in the future have clinical application as an addition to histopathological methods in the diagnosis and differential diagnosis of various malignant neoplasms, including melanocytic neoplasms, which is changing the paradigm of routine medical practice, introducing diagnostic tests that carry molecular information into it.

Orbital Involvement by Biphenotypic Sinonasal Sarcoma With a Literature Review

PURPOSE

To document a case of a biphenotypic sinonasal sarcoma that impinged on the orbit via a tumor-induced mucocele and review the previous literature devoted to this condition.

METHODS

A clinicopathologic case report with detailed histopathologic, immunohistochemical, and radiological studies with tabulations of previously reported cases and immunohistochemical stains for ruling out mimicking lesions.

RESULTS

A biphenotypic sinonasal sarcoma arose from the ethmoid sinus in a middle-aged man. The tumor induced a mucocele that bowed the medial orbital lamina papyracea into the orbit and caused diplopia and mild proptosis. The biopsy's dual positivity for S100 and smooth muscle actin together with positive paired box 3 immunohistochemical staining established the diagnosis of biphenotypic sinonasal sarcoma.

CONCLUSION

Biphenotypic sinonasal sarcoma, which can involve the orbit in 25% of cases, is a rare head and neck malignancy that has only recently been described. Biphenotypic sinonasal sarcoma is a low-grade, locally aggressive, nonmetastasizing sarcoma displaying both neural and muscle differentiation. It is further characterized by rearrangements of the PAX3 gene with multiple fusion partners, most commonly MAML3 (Mastermind like transcriptional coactivator 3). It occurs predominantly in middle-aged women and exclusively in the sinonasal tract. However, it can spread throughout the central facial structures to invade the brain if not detected early. Ophthalmologists should be aware of this new entity to avoid delays in diagnosis and treatment. The previous literature devoted to this condition was reviewed and analyzed for clinical, radiological, histopathological, and immunohistochemical features. In circumstances where molecular testing is not available, paired box 3 immunohistochemical staining can be used as an alternative diagnostic marker. The current case is most unusual because the orbital findings were induced by a mucocele caused by the tumor that obstructed the sinus ostium. This produced diplopia without direct tumor invasion into the orbital fat.

Biphenotypic Sinonasal Sarcoma: A Case Report and Review of Literature

OBJECTIVES

Biphenotypic sinonasal sarcoma (BSNS), previously low-grade sinonasal sarcoma with neural and myogenic features, is a rare tumor of the sinonasal tract first described in 2012. Due to its rarity, limited literature is available in providing clinicians with a standardized treatment regimen, particularly in cases of positive surgical margins. This article aims to provide a clinical review of the currently available reported cases of BSNS, as well as presenting clinical, radiologic, and pathologic details of 2 novel cases.

METHODS

Online electronic databases include PubMed and Embase where queried for reports of biphenotypic sinonasal sarcoma or low-grade sinonasal sarcoma with neural and myogenic features. Two previously unpublished cases were included in the results. Data including clinical presentation, epidemiologic data, radiologic evaluation, intraoperative details, histopathology, treatment modality, and postoperative follow-up information were included.

RESULTS

A total of 100 previously published cases were identified in 12 prior articles. Mean age at presentation was 52.9 years. Extrasinonasal extension was observed in 27.4% of cases with most common site of extension being cribriform plate. Forty-seven cases included treatment details with surgical excision being the most common modality. Recurrence rates were identical for both surgical excision alone and surgical excision with adjuvant radiotherapy (33.3%).

CONCLUSIONS

Biphenotypic sinonasal sarcoma is a slow-growing tumor that is amenable to surgical resection. Recurrence rates are similar between surgical excision and surgical excision with adjuvant radiation therapy, but limited data in reported cases preclude a determination of treatment superiority.

Rare Diseases of the Nose, the Paranasal Sinuses, and the Anterior Skull Base

Due to their low incidence and thus resulting limited diagnostic criteria as well as therapeutic options, rare diseases of the nose, the paranasal sinuses, and the anterior skull base are a significant challenge. The value as of which a disease has to be considered as rare amounts to a maximum of 5 patients per 10 000 people. Within these diseases, however, there are extreme differences. Some rare or orphan diseases like for example the inverted papilloma belong to regularly diagnosed and treated diseases of larger departments of oto-rhino-laryngology whereas other rare diseases and malformations have only been described in less than 100 case reports worldwide. This fact emphasizes the necessity of bundling the available experience of diagnostics and therapy. The present article gives an overview about rare diseases of the nose, the paranasal sinuses, and the anterior skull base from the field of diseases/syndromes of the olfactory system, malformations of the nose and paranasal sinuses, ventilation and functional disorders as well as benign and malignant tumors. The classification and data on diagnostic and therapeutic options were established based on the current literature.

Radiation therapy strategies for skull-base malignancies

INTRODUCTION

The management of skull base malignancies continues to evolve with improvements in surgical technique, advances in radiation delivery and novel systemic agents.

METHODS

In this review, we aim to discuss in detail the management of common skull base pathologies which typically require multimodality therapy, focusing on the radiotherapeutic aspects of care.

RESULTS

Technological advances in the administration of radiation therapy have led to a wide variety of different treatment strategies for the treatment of skull base malignances, with outcomes summarized herein.

CONCLUSION

Radiation treatment plays a key and critical role in the management of patients with skull base tumors. Recent advancements continue to improve the risk/benefit ratio for radiotherapy in this setting.

Next-Generation Sequencing Approaches for the Identification of Pathognomonic Fusion Transcripts in Sarcomas: The Experience of the Italian ACC Sarcoma Working Group

This work describes the set-up of a shared platform among the laboratories of the Alleanza Contro il Cancro (ACC) Italian Research Network for the identification of fusion transcripts in sarcomas by using Next Generation Sequencing (NGS). Different NGS approaches, including anchored multiplex PCR and hybrid capture-based panels, were employed to profile a large set of sarcomas of different histotypes. The analysis confirmed the reliability of NGS RNA-based approaches in detecting sarcoma-specific rearrangements. Overall, the anchored multiplex PCR assay proved to be a fast and easy-to-analyze approach for routine diagnostics laboratories.

Clinical management of emerging sinonasal malignancies

Several emerging sinonasal malignancies have recently been described in the pathology literature. Although not all distinctly classified by the World Health Organization, these rare tumors present a management challenge to surgeons and oncologists. While prior studies have summarized histologic details, a clinically focused review is currently lacking in the literature. This review describes the presentation, histopathology, imaging, treatment, and prognosis of newly described or recently evolving sinonasal malignancies while highlighting the distinguishing features of these entities. It includes teratocarcinosarcoma, human papillomavirus-related multiphenotypic carcinoma, biphenotypic sinonasal sarcoma, sinonasal renal cell-like adenocarcinoma, NUT-midline carcinoma, squamous cell carcinoma associated with inverted papilloma, sinonasal undifferentiated carcinoma, and INI-1-deficient sinonasal carcinoma. By describing the diagnosis, treatment, and prognosis of these recently defined entities, this clinical review aims to help guide oncologists in the clinical management of these patients.

Soft Tissue Special Issue: Biphenotypic Sinonasal Sarcoma: A Review with Emphasis on Differential Diagnosis

Biphenotypic sinonasal sarcoma is an anatomically restricted low-grade malignant neoplasm with dual neural and myogenic differentiation composed of a monotonous population of spindled cells with herringbone/fascicular architecture. These tumors demonstrate a unique immunoprofile with relatively consistent S100-protein and actin expression in conjunction with more variable desmin, myogenin and myoD1 staining. SOX10 is uniformly negative. Genetically, the majority of tumors harbor PAX3-MAML3 fusions, with alternate PAX3 partners including FOXO1, NCOA1, NCOA2 and WWTR1. Although the differential diagnosis of BSNS is broad, careful morphologic inspection together with targeted ancillary studies is often sufficient to arrive at the correct diagnosis. As these tumors have significant local recurrence rates but lack metastatic potential, awareness and accurate diagnosis of this rare and newly described neoplasm is critical for appropriate management.