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Objective: The role of elective neck dissection (END) in the management of clinical N0 (cN0) squamous cell carcinomas (SCC) of the sinonasal tract is unclear. In this systematic review, we evaluate the risk of occult nodal metastasis in sinonasal SCCs with cN0M0 tumors to support clinical decision making. Methods: A literature search was conducted in the following three electronic databases: Medline/PubMed, ScienceDirect, and Google Scholar. Articles were assessed for eligibility in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Two independent authors extracted the data. The Methodological Items for Non-Randomized Studies (MINORS) tool was used for the assessment of biases of each included study. Results: Our systematic review included six studies that met the inclusion criteria, all retrospective in design. The rate of histologically proven metastasis of sinonasal SCC to the clinically negative neck is 12.5%. Almost half of the positive cases are pathologically staged as N2 (6.5%). Conclusion: Our systematic review provides the rate of sinonasal SCC occult metastasis to the neck so that the surgeons can discuss with patients the risks and possible merits of adding an elective neck management in the surgical plan. [ABSTRACT FROM AUTHOR]

Chondro-osseous respiratory adenomatoid hamartoma (COREAH) are extremely rare benign lesions of the sinonasal tract. It is present in 3 to 83-year-olds. It originates from various sites of the sinonasal tract; the most common site is the posterior lateral wall of the nasal cavity. Imaging calcification is an important finding in COREAH. In this case report, we present an exceptionally rare occurrence involving a 55-year-old female patient who exhibited symptoms of nasal obstruction, bleeding from the left side of the nasal cavity and loss of smell. We aim to share our experience in managing this unique condition. Diagnostic nasal endoscopic examination of the patient revealed a reddish, fleshy polypoidal mass in the left nasal cavity arising from the lateral wall of the left nasal cavity posteriorly and extending anteriorly into the left nasal cavity. The patient underwent an excisional biopsy. Upon microscopic examination, we observed a hamartomatous proliferation of respiratory-type glands exhibiting mucinous metaplasia. Additionally, numerous spicules of mature bone were present, a distinctive feature of COREAH. The patient underwent a 6-month follow-up, during which no recurrent growth was detected within the nasal cavity. [ABSTRACT FROM AUTHOR]

Introduction Angioleiomyoma is a rare neoplasm that represents ∼ 0.2 % of all head and neck benign tumors and ∼ 2% of total cases of tumors of the sinonasal tract. It was once considered a possible subtype of leiomyoma, but, in the 2020 World Health Organization (WHO) classification of soft tissue tumors, it is accepted as a singular entity. Objective To systematically review the existing literature on angioleiomyoma in the light of the new classification of soft tissue tumors. Data Synthesis The present study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A comprehensive search in the PubMed, Cochrane, Scopus, and Google Scholar databases was performed in January 2022. The search items included the following keywords: nasal angioleiomyoma OR sinonasal angioleiomyoma OR nasal vascular leiomyoma OR sinonasal vascular leiomyoma. A total of 87 patients were evaluated. He age of the patients in the studies ranged from 15 to 88 years (mean age at diagnosis: 55.6 years). The most common site of involvement was the nasal septum (28.4 %), followed by the inferior turbinate (22.5%). The most common symptom was nasal obstruction (66.7%), followed by epistaxis (47.1%). Surgical excision represented the main treatment, and there was recurrence of pathology in only 1 case (0.9%). Conclusion To our knowledge, only 87 cases of sinonasal-tract angioleiomyoma have been previously described. The results of the present review seem to confirm the rarity and the benign nature of this neoplasm, and they seem to confirm the necessity to improve the available data about sinonasal-tract angioleiomyoma. [ABSTRACT FROM AUTHOR]

Introduction Angioleiomyoma is a rare neoplasm that represents ∼ 0.2 % of all head and neck benign tumors and ∼ 2% of total cases of tumors of the sinonasal tract. It was once considered a possible subtype of leiomyoma, but, in the 2020 World Health Organization (WHO) classification of soft tissue tumors, it is accepted as a singular entity.

Malignant sinonasal tumors are rarely encountered in the practice of oncology as they constitute only 1% of total body tumors. The occurrence of primitive neuroectodermal tumor (PNET) in the sinonasal tract is even more uncommon. The PNET belongs to Ewing sarcoma family and forms the differential diagnosis of a large group of lesions generally described as malignant round cell tumors. The unique pathogenetic chromosomal alteration in this lesion is the EWS FLI1 fusion gene. This case report describes the unusual occurrence of PNET for its cytomorphological diagnosis along with its clinical features, radioimaging findings and immunohistochemistry. Such case reports are scarce in literature and cytodiagnosis of PNET in sinonasal tracts warrants its sharing with medical fraternity as such diagnoses are stumbled along rarely in clinical practice.

Abstract Background Low-grade papillary Schneiderian carcinoma (LGPSC) is a relatively new entity of the sinonasal tract and is characterized by a bland morphology simulating sinonasal papilloma, invasive growth pattern with pushing borders, and aggressive clinical behavior with multiple recurrences and metastatic potential. Recently, DEK::AFF2 fusions were identified in LGPSC. However, some LPGSCs lack DEK::AFF2 fusion, and the molecular features of these tumors have not been clarified. Case presentation A 69-year-old man presented with a discharge of pus from his left cheek. Computed tomography revealed a mass involving the left maxillary sinus, ethmoid sinus, and nasal cavity with the destruction of the orbital wall. The biopsy specimens showed that the tumor had a predominantly exophytic, papillary growth and did not have an apparent stromal invasion. The tumor was composed of multilayered epithelium that showed bland morphology with a round to polygonal shape, abundant eosinophilic cytoplasm, and uniform nuclei. Dense neutrophilic infiltrates were focally present. Immunohistochemically, CK5/6 was strongly and diffusely positive, and p16 was negative. p63 was mainly positive in the basal layer, and EMA was predominantly expressed in the outermost cell layer. DNA-based targeted sequencing showed TP53 R175H mutation, whereas neither EGFR nor KRAS mutation was identified. Reverse transcription polymerase chain reaction and fluorescence in situ hybridization revealed no DEK::AFF2 fusion. Conclusions We describe the first case of TP53-mutant LGPSC and review the literature. LGPSC is a genetically heterogeneous entity, and the recognition of this rare entity and comprehensive assessment of clinicopathological and molecular findings are crucial for the correct pathological diagnosis and clinical management.

Background: Schwannomas are neoplasms that are rarely found in the sinonasal tract and pterygopalatine fossa (PPF). The objective of this study is to evaluate the schwannoma in the sinonasal tract and PPF including its effectiveness of endoscopic surgical excision of the lesion. Methods: This retrospective study was done between March 2018 and April 2022. There were nine cases of benign schwannomas found in the nasal cavity, the nasal ethmoid and the PPF. All patients had undergone endoscopic endonasal removal of the tumour. Results: All the patients successfully underwent endonasal endoscopic excision of the schwannoma from the sinonasal tract and PPF. Out of nine patients, one showed recurrence after 1 year during follow-up check-ups. None of the patients showed any major vascular complications during surgery. At follow-up, one patient presented with a persistent sensory deficit in the facial area. Conclusions: The endonasal endoscopic approach for schwannoma at the sinonasal tract and PPF is a safe and effective method for biopsy and treatment. This approach is highly effective for visualisation and has the potential to reduce complications. Pre-operative imaging is an important step before successful treatment by endoscopic endonasal removal of the schwannoma. [ABSTRACT FROM AUTHOR]

Background: Molecular diagnostics has greatly refined sinonasal tumor pathology over the past decade. While much of the attention has focused on carcinomas, it is becoming clear that there are emerging mesenchymal neoplasms which have previously defied classification. Methods: Here, we present a 33-year-old woman with a multiply recurrent sinonasal spindle cell tumor exhibiting distinctive features, and not easily classifiable into a specific category. Results: The hypercellular tumor was composed of plump spindled cells, with uniform vesicular chromatin arranged as vague fascicles around a prominent hemangiopericytoma-like vasculature. The mitotic rate was brisk at 10 per 10 high power fields. By immunohistochemistry, it was only positive for EMA (focal) and SATB2 (diffuse, weak). Fusion analysis uncovered EWSR1::BEND2, a fusion which is best known for being seen in astroblastoma, but which has not yet been reported in sarcomas. Conclusion: This case underscores the utility of fusion analysis when confronted with a sinonasal spindle cell neoplasm which does not neatly fit into any specific category. It remains to be seen if EWSR1::BEND2 sinonasal sarcoma represents a distinct entity. [ABSTRACT FROM AUTHOR]

Background: Schwannomas are neoplasms that are rarely found in the sinonasal tract and pterygopalatine fossa (PPF). The objective of this study is to evaluate the schwannoma in the sinonasal tract and PPF including its effectiveness of endoscopic surgical excision of the lesion. Methods: This retrospective study was done between March 2018 and April 2022. There were nine cases of benign schwannomas found in the nasal cavity, the nasal ethmoid and the PPF. All patients had undergone endoscopic endonasal removal of the tumour. Results: All the patients successfully underwent endonasal endoscopic excision of the schwannoma from the sinonasal tract and PPF. Out of nine patients, one showed recurrence after 1 year during follow-up check-ups. None of the patients showed any major vascular complications during surgery. At follow-up, one patient presented with a persistent sensory deficit in the facial area. Conclusions: The endonasal endoscopic approach for schwannoma at the sinonasal tract and PPF is a safe and effective method for biopsy and treatment. This approach is highly effective for visualisation and has the potential to reduce complications. Pre-operative imaging is an important step before successful treatment by endoscopic endonasal removal of the schwannoma.

Background: Low-grade papillary Schneiderian carcinoma (LGPSC) is a relatively new entity of the sinonasal tract and is characterized by a bland morphology simulating sinonasal papilloma, invasive growth pattern with pushing borders, and aggressive clinical behavior with multiple recurrences and metastatic potential. Recently, DEK::AFF2 fusions were identified in LGPSC. However, some LPGSCs lack DEK::AFF2 fusion, and the molecular features of these tumors have not been clarified. Case presentation: A 69-year-old man presented with a discharge of pus from his left cheek. Computed tomography revealed a mass involving the left maxillary sinus, ethmoid sinus, and nasal cavity with the destruction of the orbital wall. The biopsy specimens showed that the tumor had a predominantly exophytic, papillary growth and did not have an apparent stromal invasion. The tumor was composed of multilayered epithelium that showed bland morphology with a round to polygonal shape, abundant eosinophilic cytoplasm, and uniform nuclei. Dense neutrophilic infiltrates were focally present. Immunohistochemically, CK5/6 was strongly and diffusely positive, and p16 was negative. p63 was mainly positive in the basal layer, and EMA was predominantly expressed in the outermost cell layer. DNA-based targeted sequencing showed TP53 R175H mutation, whereas neither EGFR nor KRAS mutation was identified. Reverse transcription polymerase chain reaction and fluorescence in situ hybridization revealed no DEK::AFF2 fusion. Conclusions: We describe the first case of TP53-mutant LGPSC and review the literature. LGPSC is a genetically heterogeneous entity, and the recognition of this rare entity and comprehensive assessment of clinicopathological and molecular findings are crucial for the correct pathological diagnosis and clinical management. [ABSTRACT FROM AUTHOR]

Objective: To analyse the clinicopathological characteristics of sinonasal malignancies in the light of the updates regarding head and neck tumours. Method: The retrospective study was conducted at the Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan, and comprised data of patients diagnosed with primary malignant tumours of the sinonasal tract between 2015 and 2020. Slides related to biopsies and resection specimens were retrieved from the institutional database and reviewed by two pathologists. Follow-up data was also obtained. Data was analysed using SPSS 20. Results: Of the 245 samples, 144(58.7%) were epithelial tumours, 46(18.7%) neuroectodermal tumours, 41(16.7%) hematolymphoid tumours and 14(5.7%) were malignant soft tissue tumours. A heavy reliance was placed on immunohistochemical stains to diagnose poorly-differentiated tumuors. Survival was dismal, especially with early and frequent spread to the brain (33.3% in cases of Sinonasal Undifferentiated Carcinoma). Conclusion: A wide array of sinonasal malignancies was seen. Updated knowledge of the malignancies prevalent in the region is imperative for timely diagnosis and treatment. Key Words: Sinonasal tract, Squamous cell carcinoma, Sinonasal undifferentiated carcinoma, NUT c, Survival, Pakistani.

Abstract Objective Cone‐beam computed tomography (CBCT) is a promising imaging modality for sinonasal evaluation, with advantages of relatively low radiation dose, low cost, and quick outpatient imaging. Our study aimed to compare the diagnostic performance and image quality of CBCT with those of multi‐detector computed tomography (MDCT) with different slice thickness. Methods We retrospectively reviewed 60 consecutive patients who had undergone both CBCT and MDCT. MDCT images was reconstructed with 1 and 3 mm slice thickness. The quantitative image quality parameters (image noise, signal‐to‐noise ratio [SNR], and contrast‐to noise ratio [CNR] were calculated and compared between the two imaging modalities. Two observers (ENT surgeon and neuroradiologist) evaluated the presence of seven sinonasal anatomic variations in each patient and interobserver agreements were analyzed. The diagnostic performance of CBCT (0.3 mm) and MDCT (3 mm) was assessed and compared with that of high resolution MDCT (1 mm), which is considered as the gold standard. Results The image noise was significantly higher and SNR and CNR values were lower in the CBCT (0.3 mm) group than in the MDCT groups (1 and 3 mm). The diagnostic performance of CBCT (0.3 mm) was similar to that of MDCT (1 mm) and superior to that of MDCT (3 mm). The highest interobserver agreement was for high resolution MDCT (1 mm), followed by CBCT (0.3 mm), and MDCT (3 mm). Conclusion Considering its low radiation dose, low cost, and ease of clinical access, CBCT may be a useful imaging modality for as first line sinonasal evaluation and repeated follow up. Study design: Retrospective study in a tertiary referral university center. Level of evidence: NA.

(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. [ABSTRACT FROM AUTHOR]

Introduction: The worldwide annual incidence of carcinomas of the sinonasal tract is 0.5 to 1.0 patients per 100,000 per year. P63 plays a role in epithelial development and is used as a marker for basal and myoepithelial cells. Expression of p16 occurs as a result of functional inactivation of the retinoblastoma protein (pRb) by the human papilloma virus (HPV) E7 protein. Aims: This study aims to study the histological spectrum of benign and malignant sinonasal mass lesions and to study the immunohistochemical expression of p63 in different type of sinonasal mass lesions. It also aims to ascertain the incidence of high-risk HPV in primary sinonasal mass lesions with p16 immunohistochemistry and delineate the histological spectrum of HPV-related sinonasal lesions. Materials and Methods: This cross-sectional study was conducted on 80 cases from June 2018 to June 2020 at a tertiary care hospital. Clinical history including demographic parameters were collected in the study proforma. The gross findings of the specimens noted and histopathological examination by H&E staining done. Immunohistochemistry staining for p63 and p16 expression was performed on all cases. Results: Most common age group affected was 41–60 years with male:female ratio of 1.67:1. Nonneoplastic lesions (38.7%) comprised majority of the cases followed by benign neoplastic lesions (31.3%) and malignant neoplastic lesions (30%). Among the malignant neoplastic lesions, p63 showed positive expression in 75% (p = 0.005) and p16 showed positive expression in 41.7% (p = 0.023). Among benign and nonneoplastic lesions, p63 showed positivity in 21.4% (p = 0.000) and p16 showed positivity in 44.6% (p = 0.040). Conclusion: We analyzed p63 and p16 expression in varied lineages like carcinomas, papillomas, and neuroectodermal differentiation arising from the sinonasal tract and also in relation to other clinicopathological parameters. This study revealed p63 expression was associated more with the squamous cell carcinomas and nasopharyngeal carcinomas. Sinonasal tract malignancies are also associated with HPV infections that are identifiable by p16 immunostaining and, thus, could provide new prospects in identifying any definite biological and clinical characteristics associated with HPV as well as advancement in the targeted therapies for this patient population. [ABSTRACT FROM AUTHOR]

Nasal chondromesenchymal hamartoma is a rare, benign lesion that contains mixed mesenchymal elements including cartilage. These lesions typically present as nasal masses in infants who are having symptoms of respiratory distress. On imaging, the tumor may have an aggressive appearance with erosion of bone. The diagnosis is clinically significant as a nasal chondromesenchymal hamartoma may be the presenting lesion in DICER1 familial tumor susceptibility syndrome. Cartilage containing lesions of the sinonasal tract are rare and range from tumor-like lesions to malignant lesions. We review nasal chondromesenchymal hamartoma and discuss a pathologic differential diagnosis.

Objective: Cone‐beam computed tomography (CBCT) is a promising imaging modality for sinonasal evaluation, with advantages of relatively low radiation dose, low cost, and quick outpatient imaging. Our study aimed to compare the diagnostic performance and image quality of CBCT with those of multi‐detector computed tomography (MDCT) with different slice thickness. Methods: We retrospectively reviewed 60 consecutive patients who had undergone both CBCT and MDCT. MDCT images was reconstructed with 1 and 3 mm slice thickness. The quantitative image quality parameters (image noise, signal‐to‐noise ratio [SNR], and contrast‐to noise ratio [CNR] were calculated and compared between the two imaging modalities. Two observers (ENT surgeon and neuroradiologist) evaluated the presence of seven sinonasal anatomic variations in each patient and interobserver agreements were analyzed. The diagnostic performance of CBCT (0.3 mm) and MDCT (3 mm) was assessed and compared with that of high resolution MDCT (1 mm), which is considered as the gold standard. Results: The image noise was significantly higher and SNR and CNR values were lower in the CBCT (0.3 mm) group than in the MDCT groups (1 and 3 mm). The diagnostic performance of CBCT (0.3 mm) was similar to that of MDCT (1 mm) and superior to that of MDCT (3 mm). The highest interobserver agreement was for high resolution MDCT (1 mm), followed by CBCT (0.3 mm), and MDCT (3 mm). Conclusion: Considering its low radiation dose, low cost, and ease of clinical access, CBCT may be a useful imaging modality for as first line sinonasal evaluation and repeated follow up. Study design: Retrospective study in a tertiary referral university center. Level of evidence: NA. [ABSTRACT FROM AUTHOR]

There is limited literature detailing the histology of pharyngeal papillomas. Herein, we report our experience with papillomas occurring in the oro-and nasopharynx that have both squamous and respiratory features akin to the sinonasal Schneiderian papilloma. We retrospectively reviewed pharyngeal papillomas that were composed of both squamous and respiratory epithelium received at our institution between 2010 and 2020. Cases of sinonasal papillomas directly extending into the pharynx were excluded. Immunohistochemistry for p16 as well as RNA in situ hybridization to evaluate for 6 low-risk and 18 high-risk HPV genotypes were performed on all cases. Thirteen cases were included. Mean age was 61 with 12 males and 1 female. While often incidentally found, presenting symptoms included globus sensation, hemoptysis, and hoarseness of voice. Histologically, all tumors consisted of squamous and respiratory epithelium with neutrophilic infiltrates arranged in an exophytic/papillary architecture that was reminiscent of the exophytic type of Schneiderian papilloma. Immunohistochemistry for p16 was negative in all papillomas. 85% were positive for low-risk human papillomavirus (HPV) subtypes and all were negative for high-risk HPV subtypes. A well-differentiated, invasive squamous cell carcinoma was associated with two of the cases. Papillomas with squamous and respiratory features similar to the sinonasal exophytic Schneiderian papilloma can arise in the oro- and nasopharynx and like their sinonasal counterparts show an association with HPV. While many in this series were benign, they can be harbingers for invasive squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

Background: Primary sinonasal non-Hodgkin's lymphomas (NHLs) are uncommon malignancies. The lack of specific clinical presentations often causes delayed visit to the clinician and so diagnosis is done in late with advanced stage. Objective: The objective of the study was to study the primary sinonasal NHL with respect to clinical presentations, management, and outcome. Materials and Methods: This is a retrospective study conducted in a tertiary care teaching hospital from March 2010 to April 2020. The clinical data of the patients of primary sinonasal NHL were evaluated with respect to the age, sex, clinical presentations, staging, diagnosis, treatment, and outcome. Results: The mean age of the participants was 62.45 years with male-to-female ratio of 1.5:1. All the cases of sinonasal NHL involved with paranasal sinuses and nasal cavity. Nasal obstruction was the most common symptom. All were diagnosed with large B-cell lymphoma and treated with combined chemotherapy and radiation. Five patients were died during follow-up period. Conclusion: Primary sinonasal NHLs are extremely uncommon clinical entity. The diagnosis is based on the histological examination with immunohistochemical study. Early diagnosis and prompt treatment with chemo-regimen and radiotherapy are essential to achieve an optimum outcome. Early diagnosis and treatment improves the treatment outcome.

Combined neuroendocrine and squamous cell carcinoma (SCC) of the sinonasal tract is rare entity but is increasingly gaining recognition within the head and neck pathology community. In a recent series, a single case was reported to demonstrate diffuse p16 positivity despite lacking high-risk human papillomavirus (HPV) by RNA in-situ hybridisation (ISH). Here we describe a case of p16 positive combined neuroendocrine and SCC containing high-risk HPV. Retrospective case review of sinonasal carcinomas within the Head and Neck Pathology Department at Guy's and St Thomas' NHS Foundation Trust identified a single case of combined neuroendocrine and SCC. Clinico-demographic data was obtained through electronic hospital records. All immunohistochemistry and in-situ hybridisation were undertaken according to departmental standard operating procedures. Routine microscopy showed the tumour to comprise small and large cell neuroendocrine components as well as squamous and spindle cell elements. Small and large cells demonstrated CD56 and synaptophysin expression, whereas CK5/6 and p63 were confined to squamous components. There was diffuse p16 expression and punctate nuclear positivity for DNA ISH. We describe a case of HPV-associated combined neuroendocrine and SCC of the sinonasal tract. Recognition of HPV association with this entity avoids diagnostic pitfalls. [ABSTRACT FROM AUTHOR]

Background Meningiomas are usually benign tumors and account for 15% of the overall intracranial tumors. Less than 3% of them extend up to the sinonasal region. Case Report A 61-year-old woman, operated on for a huge olfactory meningioma 8 years before, came for progressive nasal obstruction. On physical examination, a mass that completely obliterated the right nasal passage was detected. A c.e. cranial MRI confirmed the presence of an enhancing mass completely occupying the right nostril, without intracranial extension. A biopsy of the mass revealed a meningioma (WHO grade I) and the patient was admitted to our department for the surgical removal of the endonasal recurrent tumor. Results The meningioma was approached and excised by endonasal endoscopic approach using a microdebrider and electrocautery. A linear residual of tumor was left attached to the previous anterior skull base’ vascularized galeal flap, in order to avoid a communication with the intracranial compartment and a possible cerebrospinal fluid (CSF) leak. The postoperative course was uneventful, and the patient immediately referred an improvement in breathing. A c.e. postoperative MRI confirmed the nearly total removal of tumor. Conclusions We present a video with the most relevant steps of transnasal endoscopic surgical removal of a quite rare case of a recurrent olfactory groove meningioma, completely obliterating the right nostril.

Large B cell lymphomas (LBCL) are a heterogeneous group of diseases with variable presentations and prognoses. Rarely, LBCLs arise in the sinonasal tract and are distinct from extranodal NK/T-cell lymphoma which is more typical in this anatomic location. We hypothesized that large B cell lymphoma primary to the sinonasal tract (snLBCL) would be heterogeneous and include high-grade B cell lymphomas (HGBCL) described in the revised 4th edition WHO classification of lymphomas. We retrospectively evaluated cases of snLBCL at our center, and performed additional immunohistochemical and in situ hybridization studies where needed for modern WHO classification. Our cohort consisted of 25 cases, 15 males and 10 female patients, aged 14 to 87 years, with predominantly nasopharyngeal disease (n = 11), Ann Arbor stage IIE (n = 15), and immunocompetence (n = 24). According to revised 2016 WHO criteria, 20 of the 25 cases were DLBCL-NOS (80%, two-thirds germinal center phenotype), 3 were HGBCL-NOS (8%, one with MYC rearrangement without BCL2 rearrangement), and 2 were EBV-LBCL (8%). Among DLBCL-NOS, those arising in the nasopharynx all showed a germinal center B cell (GCB) phenotype, whereas both evaluable maxillary sinus tumors showed non-GCB characteristics (p = 0.02). These data show that large B cell lymphoma primary to the sinonasal tract is histopathologically heterogeneous as systemic large B cell lymphoma. The observation that GCB and non-GCB tumors differs in anatomic location suggests that microenvironmental factors in sinonasal anatomic sites may drive lymphoma characteristics. [ABSTRACT FROM AUTHOR]

Introduction: Thesinonasal tract is an area that may be affected by various types of neoplastic lesions with more variety than what is encountered in other parts of the upper airway and food passage. Case Report: An elderly gentleman of 65 years complained of nose block on both sides for 3 months. On examination, he had firm polypoidal masses arising from the middle meatus and septum on both sides. Computed tomography scan of the sinuses revealed polypoidal mucosal thickening in bilateral sinuses with bilateral concha bullosa. The patient underwent functional endoscopic sinus surgery with the complete excision of the masses from the lateral wall and septum under general anesthesia. The results of the histopathological examination showed inflammatory changes in polypoidal tissues from the right maxillary, bilateral ethmoidal sinuses, and bilateral septal masses. The lesion in the left middle meatus showed the features of respiratory epithelial adenomatoid hamartoma (READ). The case had no evidence of residual or recurrent lesion during 6 months after the surgery. Conclusion: The READ is a rare lesion observed in the sinonasal tract. It is a diagnostic dilemma for clinicians as it can be misdiagnosed as neoplastic lesions, such as inverted papilloma or adenocarcinoma, which would warrant radical surgery or sinonasal polyposis and be treated inadequately.

This report presents a case of a rarely occurring inverted squamous papilloma, which shows papillary proliferation in squamous epithelium. Inverted papillomas (IPs) are benign epithelial growths that occur in the underlying stroma of the nasal cavity and paranasal sinuses. While viral infections, allergies, and chronic sinusitis have all been proposed as potential causes, the pathophysiology of this lesion is still unknown. Most of the time, IP reflects residual disease, yet the recurrence rates are extremely high. A 60-year-old male patient has chief complaints of right-sided nasal congestion and excessive sneezing and discharge from the nose, which cause discomfort to the patient and make him unable to sleep at night. Computed tomography reveals both the enlargement of the osteomeatal complex and soft-tissue density opacification of the right side of the nasal cavity. The only way to diagnose this type of squamous papilloma is through histopathological examination. In this work, we evaluated the histological characteristics of sinonasal IP and presented a case report of an uncommon instance of inverted squamous papilloma of the nasal cavity., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Bhoyar et al.)

Background: Extramedullary plasmacytomas are tumors that develop from plasma cells and rarely express anaplastic features. To our knowledge, there have only been three reported cases of anaplastic plasmacytomas of the sinonasal tract in the English literature. We detail the fourth case. Methods: A 70‐year‐old male was seen with a 4‐month history of nasal congestion, bloody mucous, and left sided nasal obstruction. On positron emission tomography/computed tomography, the lesion was FDG‐avid with an SUVmax of 25.1. A biopsy of the lesion and subsequent immunohistochemical staining confirmed the diagnosis of an anaplastic plasmacytoma. Results: The patient is undergoing a 5‐week course of curative‐intent radiation therapy. Conclusion: Extramedullary plasmacytomas with anaplastic features are very rare. We highlight the value of thorough histopathological review and detailed immunostains to arrive at a diagnosis of anaplastic extramedullary plasmacytoma. [ABSTRACT FROM AUTHOR]

Aims: Low‐grade papillary Schneiderian carcinoma (LGPSC) is a rare and newly described entity of the sinonasal tract. The aim of this study was to evaluate the clinicopathological and molecular characteristics in order to identify typical features for differential diagnosis. Methods and results: Of the 3000 cases of sinonasal tumour studied during a period of 6 years, five cases were reviewed and diagnosed as LGPSC. All five patients were female (mean age, 47.8 years; range, 18–64 years) and had undergone multiple surgeries (3–10 surgeries). Both the sinonasal tract and the middle ear were involved in four patients. Nodal metastasis occurred in two patients, and one patient developed a distant metastasis to the left lung. Histologically, tumours had branched and crowded papillae with pushing boundaries. Tumour epithelia were multilayered and arranged in an orderly pattern without cilia. No malignant cytological features were observed in any of the cases. Immunohistochemical findings revealed a scattered distribution of Ki67‐positive cells and positive staining for epithelial membrane antigen, mainly in the outermost‐layer cells. Human papillomavirus (HPV) DNA was found in two patients and genotyped as HPV type 16. Sanger sequencing did not reveal any epidermal growth factor receptor or Kirsten rat sarcoma viral oncogene homologue gene mutation in the five cases. Conclusions: We report on five new cases of LGPSC, and confirm LGPSC as a new sinonasal carcinoma that behaves aggressively with metastatic potential. The combination of clinical behaviour and typical histological features can distinguish LGPSC from sinonasal papilloma and other carcinomas. [ABSTRACT FROM AUTHOR]

Traditionally, sinonasal adenocarcinomas have been subdivided into intestinal (ITAC) and non-intestinal (non-ITAC) categories. The latter encompasses salivary-type adenocarcinomas originating from the seromucinous glands of the sinonasal mucosa and non-salivary adenocarcinomas. The non-salivary adenocarcinoma category is further subdivided into low-and high-grade variants. Among salivary-type sinonasal adenocarcinomas, tumors recapitulating salivary duct carcinoma (SDC) are exceedingly rare, but some might have been lumped into the high-grade non-ITAC category. To date, only three primary SDCs originating in the sinonasal tract have been reported. We herein describe 7 cases of SDC including one previously reported case (4 primary sinonasal, 3 metastatic/ extension from parotid gland SDC). The primary tumors affected 3 males and one female aged 60 – 75. Different sites were involved by the primary tumors while the secondary tumors affected the sphenoidal (2) and the frontal + maxillary (1) sinuses. Three primary tumors were de novo high-grade SDC and one was confined to contours of a pre-existing pleomorphic adenoma. All 3 secondary tumors were SDC ex pleomorphic adenoma of the parotid with a long history of recurrences, ultimately involving the sinonasal tract. Androgen receptor was positive in 7/7 cases. Four of 6 cases were strongly HER2/neu + (either score 3 + or with verified amplification). This small case series adds to the delineation of primary sinonasal SDC highlighting that almost half of invasive SDC presenting within sinonasal tract indeed represents extension or metastasis from a parotid gland primary. There is a tendency towards overrepresentation of HER2/neu-positive cases in both categories (primary and metastatic), but this needs clarification in larger studies. [ABSTRACT FROM AUTHOR]

Background: Ewing sarcoma (ES) is an aggressive tumour which is typically skeletal in origin. ES involving the head and neck region is uncommon and can be easily confused with other small round blue cell tumours. We herein present a rare case of ES involving the sinonasal area. Case presentation: A 5-year-old Somalian boy with no known medical illness presented with progressive nasal blockage associated with clear nasal discharge and intermittent spontaneous epistaxis for three months. CT paranasal sinus and neck region revealed poorly enhancing expansile mass in the right maxillary sinus with areas of necrosis within. Initial radiological differential diagnoses were lymphoma and rhabdomyosarcoma. The mass was biopsied and histologically showed diffuse sheets of small round blue cells that was positive to CD99, NSE and vimentin. The muscle and lymphoid markers were negative. Fluorescence in-situ hybridisation (FISH) study revealed the presence of EWSR1 gene rearrangement thus diagnosis of ES was rendered. Conclusions: ES of sinonasal tract is a rare entity and its pathological features significantly overlap with others small round blue cells tumour. Demonstration of EWSR1 gene translocation is recommended for the diagnosis of ES particularly at uncommon sites. [ABSTRACT FROM AUTHOR]

(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.

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC), is a new entity that is restricted to the sinonasal tract and is associated with high-risk HPV. This tumor is suggested to have an indolent behavior with a better prognosis than other carcinomas. We report a unique case of HMSC with a locally aggressive behavior. It is about a 61-year-old men presented with 12 months of unilateral progressive olfactory dysfunction accompanied by exophthalmia of the left eye, declining vision and headaches for 6 months. Computed tomography imaging revealed a voluminous mass occupying the ethmoid, maxillary and frontal sinus with bony destruction of the left ethmoidal blade. Histology showed a tumor composed of variably sized nests, separated by thick mucoid stroma. Tumor cells are plasmacytoid with hyperchromatic nuclei and frequent mitoses. Immunohistochemistry revealed that these cells were positive for cytokeratin AE1/AE3, p16 and negative for CK7, CK20, CD117, p40, p63, S100, synaptophysin and chromogranin. [ABSTRACT FROM AUTHOR]

Background: Primary sinonasal non-Hodgkin's lymphomas (NHLs) are uncommon malignancies. The lack of specific clinical presentations often causes delayed visit to the clinician and so diagnosis is done in late with advanced stage. Objective: The objective of the study was to study the primary sinonasal NHL with respect to clinical presentations, management, and outcome. Materials and Methods: This is a retrospective study conducted in a tertiary care teaching hospital from March 2010 to April 2020. The clinical data of the patients of primary sinonasal NHL were evaluated with respect to the age, sex, clinical presentations, staging, diagnosis, treatment, and outcome. Results: The mean age of the participants was 62.45 years with male-to-female ratio of 1.5:1. All the cases of sinonasal NHL involved with paranasal sinuses and nasal cavity. Nasal obstruction was the most common symptom. All were diagnosed with large B-cell lymphoma and treated with combined chemotherapy and radiation. Five patients were died during follow-up period. Conclusion: Primary sinonasal NHLs are extremely uncommon clinical entity. The diagnosis is based on the histological examination with immunohistochemical study. Early diagnosis and prompt treatment with chemo-regimen and radiotherapy are essential to achieve an optimum outcome. Early diagnosis and treatment improves the treatment outcome. [ABSTRACT FROM AUTHOR]

Fibroinflammatory lesions of the sinonasal tract are one of the most common head and neck lesions submitted to surgical pathology. When the fibroinflammatory pattern represents the lesion (i.e., not surface reactive ulceration), an algorithmic approach can be useful. Separated into reactive, infectious, and neoplastic, and then further divided based on common to rare, this logical progression through a series of differential considerations allows for many of these lesions to be correctly diagnosed. The reactive lesions include chronic rhinosinusitis and polyps, granulomatosis with polyangiitis, and eosinophilic angiocentric fibrosis. Infectious etiologies include acute invasive fungal rhinosinusitis, rhinoscleroma, and mycobacterial infections. The neoplastic category includes lobular capillary hemangioma, inflammatory myofibroblastic tumor, and NK/T-cell lymphoma, nasal type. Utilizing patterns of growth, dominant cell types, and additional histologic features, selected ancillary studies help to confirm the diagnosis, guiding further clinical management. [ABSTRACT FROM AUTHOR]

Sinonasal ameloblastoma is an extremely rare neoplasm. Herein we present a case of sinonasal ameloblastoma and discuss its histogenesis and related morphological characteristics. An 80 years-old Japanese male had a polypoid mass initially diagnosed as a nasal polyp. A prior biopsy was interpreted as a salivary gland-type tumor and he was therefore referred to a regional general hospital for surgical removal of the lesion. Preoperative contrast-enhanced magnetic resonance imaging revealed a space-occupying lesion in the right nasal cavity and the right maxillary sinus with poor contrast enhancement. Histopathological findings revealed that the tumor consisted of follicular/plexiform-like cell nests with peripheral palisading, extending continuously to the adjacent mucosa. A recurrent polypoid mass accompanied by bone destruction of the maxillary sinus was found two years after the surgery, but it was left untreated. Although sinonasal ameloblastoma remains under-recognized, its characteristics, including its histopathological features, need to be more widely known to allow its correct diagnosis and adequate management.

OBJECTIVE: To describe the clinical, epidemiologic behavior and therapeutic handle of the cases subjected to craniofacial resections for the treatment of the sinonasal tract malignancies. MATERIALS AND METHODS: An observational, descriptive and transversal study was performed from January 2012 to July 2015 in the National Institute of Oncology and Radiobiology of Cuba. The variables included: sex, age, primary site, signs and symptoms, histologic type, previous treatment, status of the surgical margins, intracranial invasion, status after two years, surgical technique, reconstruction method and complications; descriptive statistic was used to accomplish the results. RESULTS: A total of 39 clinical charts were reviewed. In this study, the male sex prevailed (69.2%), being placed more frequently in the ethmoid sinus (64.1%) with nasal obstruction as prevailing symptom. Sarcomas represented 30.8% of the histologies and 71.8% of the cases were alive and controlled at 2 years. The 84.6% of the approaches were through bilateral frontobasal craniotomy using in all cases the pericraneal flap for reconstruction and occurring cerebral edema in the 84.6% of the cases. CONCLUSIONS: In this study was determined a male sex prevailing, sarcomas were the most representative histology. There were few severe complications and postopera-tive mortality with a high survival determined by prognostic factors such as surgical margins and intracranial invasion. [ABSTRACT FROM AUTHOR]

Sinonasal malignant mucosal melanoma (SNM) is a rare, aggressive malignancy. The diagnosis of SNM is often quite challenging due to anatomical limitations, frequent lack of pigmentation, variable histologic appearances, and aberrant differentiation (e.g., positivity for cytokeratin, desmin, or neuroendocrine markers). S100 protein is routinely used as a standard screening marker for SNM, but it may lack optimal sensitivity. Our objective was to study the extent of immunohistochemical expression of S100 protein in SNM, and determine its diagnostic value by comparing it to a newer melanoma marker, SOX10. Twenty-three cases of sinonasal MMM were retrieved from the archival files of the Department of Pathology at UT Southwestern Medical Center. The patients included 14 men and 9 women, and ranged from 36 to 90 years (mean 64.9 years). Sections from blocks of formalin-fixed, paraffin-embedded tissue were used for immunohistochemical analysis with S100 protein and SOX10. The extent and intensity of immunostaining was recorded, and H-score was calculated. For a subset of negative or focally positive cases, S100 protein was repeated at a high-volume reference laboratory. S100 protein immunoexpression was quite variable in the SNM cases, with H-scores ranging from 0 to 300 (mean 123). While 11 of 23 cases exhibited strong and diffuse staining (H-score > 100) as expected for melanoma, 7 were weak and/or focal (H-score 1–100), and 5 were completely S100 protein-negative. For 10 cases, the negative or focal results were confirmed by reference laboratory staining. In contrast, all 23 SNM cases were diffusely and strongly positive for SOX10 (H-scores 210–300, mean 296). Our study demonstrated that S100 protein immunoexpression is extremely variable in SNM. Weak or even absent S100 protein staining is not uncommon in SNM, and should not dissuade pathologists from that diagnosis. Our data demonstrates that S100 protein is insufficiently sensitive to be used as a screening marker for SNM, but that SOX10 is consistently and robustly positive, and should therefore replace S100 protein for that purpose. Indeed, for any high-grade sinonasal tumor, pathologists must have a low threshold for utilizing additional markers to exclude the possibility of SNM. [ABSTRACT FROM AUTHOR]

Cavernous haemangioma of the maxillary sinus often presents with recurrent epistaxis and nasal obstruction. Clinical features usually mimics sinonasal mass or antrochoanal polyp. We report this case of a 13 years old female patient with unilateral maxillary sinus cavernous haemangioma which was managed successfully by both endoscopic and Caldwell Luc approach. The patient presented with features of antrochoanal polyp. Radiologically, it was suspected to be an Angiomatous Antrochoanal polyp and histologically proved to be a cavernous haemangioma. Postoperative period was uneventful.

Background: High uptake of F18-fluorodeoxyglucose parameters for glucose metabolism is related to shorter survival in sinonasal tract cancer with various histological classifications. We investigated whether F18-fluorodeoxyglucose uptake parameters are associated with survival outcomes for patients with only squamous cell carcinoma (SCC) in the sinonasal tract that are treated either with surgery or nonsurgery. Methods: We retrospectively observed F18-fluorodeoxyglucose uptake parameters on positron emission tomography with computed tomography for the primary tumour of SCC in 39 patients. Log-rank test or a Cox regression model with 95% confidence interval (95%CI) and hazard ratio (HR) were used for monovariable or multivariable analysis, respectively. We determined cut-off values of the F18-fluorodeoxyglucose uptake parameters using the lowest p value for monovariable sinonasal tract cancer-specific survival analysis. Results: Monovariable analysis showed that patients with metabolic tumour volume (MTV) ≥ 21.8 had a shorter cancer-specific, disease-free and local recurrence-free survival than those with MTV < 21.8. After adjusting for age, gender, clinical stage and treatment group in the multivariable analysis, MTV (≥21.8/

Introduction: The sinonasal tract is an area that may be affected by various types of neoplastic lesions with more variety than what is encountered in other parts of the upper airway and food passage. Case Report: An elderly gentleman of 65 years complained of nose block on both sides for 3 months. On examination, he had firm polypoidal masses arising from the middle meatus and septum on both sides. Computed tomography scan of the sinuses revealed polypoidal mucosal thickening in bilateral sinuses with bilateral concha bullosa. The patient underwent functional endoscopic sinus surgery with the complete excision of the masses from the lateral wall and septum under general anesthesia. The results of the histopathological examination showed inflammatory changes in polypoidal tissues from the right maxillary, bilateral ethmoidal sinuses, and bilateral septal masses. The lesion in the left middle meatus showed the features of respiratory epithelial adenomatoid hamartoma (READ). The case had no evidence of residual or recurrent lesion during 6 months after the surgery. Conclusion: The READ is a rare lesion observed in the sinonasal tract. It is a diagnostic dilemma for clinicians as it can be misdiagnosed as neoplastic lesions, such as inverted papilloma or adenocarcinoma, which would warrant radical surgery or sinonasal polyposis and be treated inadequately. [ABSTRACT FROM AUTHOR]

Abstract Background Sinonasal renal cell-like carcinoma (SRCLC) is an extremely rare low malignant tumor arising in the sinonasal tract, with histological mimicry of renal cell carcinoma. Case presentation We present a case of sinonasal renal cell-like carcinoma in a 63-year-old male patient. Computer tomography(CT) scanning revealed a soft tissue mass at the left nasal cavity and choana. Histologically, the predominant tumor architecture was follicular to glandular with intervening fibrous septa. The tumor cells were uniform cuboidal to polyhedral with abundant clear or eosinophilic cytoplasm. Immunohistochemically, the tumor cells were strongly positive for CK7, EMA, vimentin, SOX10, S-100, and focally positive for CA9. During 6 months of follow-up, there was no clinical or radiological evidence of recurrence or metastasis. Conclusion SRCLC has microscopic features which overlap with tumors that contain clear cells. Thus, several other tumors must be considered in the differential diagnosis of a tumor of the sinonasal region with clear cells, especially metastatic renal clear cell carcinoma. SRCLC is an indolent tumor and none of the reported SRCLC patients had metastatic disease.

A 23-year-old male presented with a 3-month history of left purulent rhinorrhea, progressive nasal obstruction, and intermittent epistaxis. A fiberoptic examination revealed a large vascular polypoid mass completely filling the left nasal cavity. CT and MRI scans showed a large hypervascular mass involving the left nasal airway, maxillary antrum, and the anterior ethmoid cells. There was no bony erosion or contiguous spread, and the remaining sinuses, orbit, and cranial fossa were uninvolved. The patient underwent complete removal of the mass via an external lateral rhinotomy approach. The soft mass was large and vascular. A microscopic analysis revealed an undifferentiated tumor consisting of a solid sheet of small, round blue cells. Mitotic figures were also present. Immunohistochemically, the tumor cells were strongly positive for CD99. Molecular studies using a PCR confirmed the chromosomal translocation of FLI1 (exon 6). These findings were considered diagnostic for Ewing’s sarcoma. Postoperatively, the patient was treated with combined chemotherapy and radiotherapy. Adjuvant chemotherapy consisting of vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (total: 7 cycles) was commenced. He also received radiation therapy for local control (total dose: 50.4 Gy). The patient is currently alive without any evidence of recurrence or metastasis.

Background  Meningiomas are usually benign tumors and account for 15% of the overall intracranial tumors. Less than 3% of them extend up to the sinonasal region. Case Report  A 61-year-old woman, operated on for a huge olfactory meningioma 8 years before, came for progressive nasal obstruction. On physical examination, a mass that completely obliterated the right nasal passage was detected. A c.e. cranial MRI confirmed the presence of an enhancing mass completely occupying the right nostril, without intracranial extension. A biopsy of the mass revealed a meningioma (WHO grade I) and the patient was admitted to our department for the surgical removal of the endonasal recurrent tumor. Results  The meningioma was approached and excised by endonasal endoscopic approach using a microdebrider and electrocautery. A linear residual of tumor was left attached to the previous anterior skull base' vascularized galeal flap, in order to avoid a communication with the intracranial compartment and a possible cerebrospinal fluid (CSF) leak. The postoperative course was uneventful, and the patient immediately referred an improvement in breathing. A c.e. postoperative MRI confirmed the nearly total removal of tumor. Conclusions  We present a video with the most relevant steps of transnasal endoscopic surgical removal of a quite rare case of a recurrent olfactory groove meningioma, completely obliterating the right nostril. [ABSTRACT FROM AUTHOR]

EWSR1::POU2AF3 (COLCA2) sarcomas are a recently identified group of undifferentiated round/spindle cell neoplasms with a predilection for the head and neck region. Herein, we report our experience with 8 cases, occurring in 5 men and 3 women (age range, 37-74 years; median, 60 years). Tumors involved the head/neck (4 cases), and one each the thigh, thoracic wall, fibula, and lung. Seven patients received multimodal therapy; 1 patient was treated only with surgery. Clinical follow-up (8 patients; range, 4-122 months; median, 32 months) showed 5 patients with metastases (often multifocal, with a latency ranging from 7 to 119 months), and 3 of them also with local recurrence. The median local recurrence-free and metastasis-free survival rates were 24 months and 29 months, respectively. Of the 8 patients, 1 died of an unknown cause, 4 were alive with metastatic disease, 1 was alive with unresectable local disease, and 2 were without disease. The tumors were composed of 2 morphologic subgroups: (1) relatively bland tumors consisting of spindled to stellate cells with varying cellularity and fibromyxoid stroma (2 cases) and (2) overtly malignant tumors composed of nests of "neuroendocrine-appearing" round cells surrounded by spindled cells (6 cases). Individual cases in the second group showed glandular, osteogenic, or rhabdomyoblastic differentiation. Immunohistochemical results included CD56 (4/4 cases), GFAP (5/8), SATB2 (4/6), keratin (AE1/AE3) (5/8), and S100 protein (4/7). RNA sequencing identified EWSR1::POU2AF3 gene fusion in all cases. EWSR1 gene rearrangement was confirmed by fluorescence in situ hybridization in 5 cases. Our findings confirm the head/neck predilection and aggressive clinical behavior of EWSR1::POU2AF3 sarcomas and widen the morphologic spectrum of these rare lesions to include relatively bland spindle cell tumors and tumors with divergent differentiation., (Copyright © 2023 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights reserved.)

Background: Head and neck mucosal melanomas are rare malignancies. Although the prognosis is poor owing to the high incidence of distant metastases, locoregional control remains important. It is difficult to obtain results in a large cohort because of its rarity. This study aimed to elucidate the survival outcomes of patients with head and neck mucosal melanoma treated with surgery in Japan., Methods: Patients with head and neck mucosal melanoma who were surgically treated between 2007 and 2021 at the National Cancer Center Hospital were retrospectively analyzed., Results: A total of 47 patients were included in this study. The 5-year overall survival, disease-specific survival, locoregional control and relapse-free survival rates were 42%, 50%, 79% and 13%, respectively. The disease-specific survival of the oral mucosal melanoma group was significantly better than that of the sinonasal mucosal melanoma group (5-year disease-specific survival rate: 70% versus 37%, respectively; P = 0.04). Multivariate analyses revealed that sinonasal mucosal melanoma were independently significant adverse prognostic factor, for overall survival and disease-specific survival. Patients with oral mucosal melanoma patients had a higher incidence of lymph node metastasis than those with sinonasal mucosal melanoma patients (P < 0.0001)., Conclusion: This study demonstrated the survival outcomes of the largest cohort of patients with head and neck mucosal melanomas treated surgically at a single institution within the past 20 years in Japan. We found that survival outcomes and incidence of nodal metastases varied by site., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)