INI-1 (SMARCB1)-Deficient Undifferentiated Sinonasal Carcinoma: Novel Paradigm of Molecular Testing in the Diagnosis and Management of Sinonasal Malignancies

SWI/SNF-Related Matrix-Associated Actin-Dependent Regulator of Chromatin Subfamily B Member 1 (SMARCB1)-Deficient Tumor in the Parapharyngeal Space: A Case Report

SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1) is a tumor suppressor gene, and SMARCB1 deficits have been associated with numerous malignant tumors. Carcinomas with a SMARCB1 deficit generally have a poor prognosis. In the head and neck region, there have been many recent cases of SMARCB1-deficient sinonasal carcinoma, but reports of extrasinonasal sites are extremely rare. This study reports a case of SMARCB1-deficient tumor in the right parapharyngeal space. A 64-year-old woman with right neck swelling was presented to our hospital, and imaging revealed a tumor in the right parapharyngeal space. After four years of follow-up, the tumor had increased in size, and a biopsy revealed deficits in SMARCB1 in the tumor cells. No definitive histological diagnoses were made. Radiation reduced the size of the tumor, and the patient survived without progression, three years after completion of treatment.

SMARCB1 (INI-1) deficient sinonasal carcinoma of the right maxillary sinus - A rare entity

INTRODUCTION AND IMPORTANCE

SMARCB1 (INI-1) is a vital tumour suppressor gene on chromosome 22q11.2, preventing tumour development in the SWI/SNF complex. Mutations cause SMARCB1-deficient tumours with distinct features. Loss of INI-1 expression is seen in malignancies, including sinonasal carcinoma and atypical teratoid/rhabdoid tumours. Recently recognized as a separate entity, SMARCB1-deficient sinonasal carcinomas (SDSC) are rare, clinically aggressive, and mimic other malignancies, emphasizing their significant diagnosis due to poorer prognosis, particularly in the elderly.

CASE PRESENTATION

A 66-year-old male presented with a 4-month-old right cheek swelling, diagnosed initially as a sinonasal neoplastic mass. The biopsy revealed sinonasal mucosal fragments infiltrated by a tumour with plasmacytoid morphology. Immunohistochemistry (IHC) of the tumour cells was positive for p63 and pan-cytokeratin and showed INI-1 loss. Subsequent subtotal maxillectomy was performed, and the patient received adjuvant chemotherapy and radiotherapy. At a thirteen-month follow-up, the patient achieved his daily activities with no signs of recurrence.

CLINICAL DISCUSSION

The loss of protein expression in sinonasal cancer is predominantly attributed to the homozygous deletion of SMARCB1. SDSC, a profoundly invasive malignant carcinoma, tends to infiltrate sinuses and extend into the intracranial regions. The IHC findings of our case were in coherence with previous studies in SMARCB1. The prognosis is particularly unfavourable in males and advanced tumours.

CONCLUSION

The tumour's microscopic and immunohistochemical characteristics indicated the SDSC. Due to its aggressive nature and high mortality rates, dealing with a paranasal mass, one should be suspicious of this tumour.

A unique case of epithelioid sarcoma involving the mandibular alveolar mucosa

Epithelioid sarcoma (ES) is an infrequent, malignant, mesenchymal, soft-tissue neoplasm of uncertain histogenesis characterized by epithelioid cytomorphology. The lack of SMARCB1/INI1 (Integrase interactor 1) expression typifies this pathology. It usually presents as a painless, indolent, slowly enlarging lesion or rarely as an aggressive growth. Epithelioid sarcoma affects mostly pediatric patients or young adults. It recurs quite frequently and possesses a high degree of metastatic potential. Two predominant histomorphologic patterns include classic/conventional type and proximal types. Epithelioid sarcoma immunohistochemically shows vimentin, cytokeratin, epithelial membrane antigen, CD34 positivity, and negative staining with S100 and desmin. Management is generally multimodal, including wide surgical resection, radiotherapy, and chemotherapy. To date, to our knowledge, only 11 instances of head and neck ES have been reported in the literature. Our case deals with the diagnosis of intraoral ES in a 55-year-old female patient, probably the first one to involve the mandibular mucosa, based on relevant clinical-radiologic-pathologic-immunohistochemical findings.

Clinicopathological features and prognostic outcomes of molecularly defined entities in the new edition of the WHO classification of sinonasal carcinoma

Introduction

We investigated the clinicopathological features and prognoses of the new molecularly defined entities in latest edition of the World Health Organization (WHO) classification of sinonasal carcinoma (SNC).

Methods

Integrated data were combined into an individual patient data (IPD) meta-analysis.

Results

We included 61 studies with 278 SNCs including 25 IDH2-mutant, 41 NUT carcinoma, 187 SWI/SNF loss, and 25 triple negative SNCs (without IDH2 mutation, NUTM1 rearrangement, and SWI/SNF inactivation) for analyses. Compared to other molecular groups, NUT carcinoma was associated with a younger age at presentation and an inferior disease-specific survival. Among SNCs with SWI/SNF inactivation, SMARCB1-deficient tumors presented later in life and were associated with a higher rate of radiotherapy administration. SMARCA4-deficiency was mostly found in teratocarcinosarcoma while SMARCB1-deficient tumors were associated with undifferentiated carcinoma and non-keratinizing squamous cell carcinoma.

Conclusion

Our study facilitates our current understanding of this developing molecular-defined spectrum of tumors and their prognoses.

Molecular Basis and Rationale for the Use of Targeted Agents and Immunotherapy in Sinonasal Cancers

Despite the progress of surgery, radiotherapy, and neoadjuvant chemotherapy, the prognosis for advanced sinonasal cancers (SNCs) remains poor. In the era of precision medicine, more research has been conducted on the molecular pathways and recurrent mutations of SNCs, with the aim of understanding carcinogenesis, helping with diagnosis, identifying prognostic factors, and finding potentially targetable mutations. In the treatment of SNC, immunotherapy is rarely used, and no targeted therapies have been approved, partly because these tumors are usually excluded from major clinical trials. Data on the efficacy of targeted agents and immune checkpoint inhibitors are scarce. Despite those issues, a tumor-agnostic treatment approach based on targeted drugs against a detected genetic mutation is growing in several settings and cancer subtypes, and could also be proposed for SNCs. Our work aims to provide an overview of the main molecular pathways altered in the different epithelial subtypes of sinonasal and skull base tumors, focusing on the possible actionable mutations for which potential target therapies are already approved in other cancer types.

SMARCB1 (INI-1)-Deficient Sinonasal Carcinoma: A Systematic Review and Pooled Analysis of Treatment Outcomes

(1) Background: SMARCB1 (INI-1)-deficient sinonasal carcinoma is a rare sinonasal malignancy; since its discovery and description in 2014, less than 200 cases have been identified. It is almost impossible to perform randomized-controlled trials on novel therapy to improve treatment outcomes in view of its rarity. We performed a systematic review of all the published case reports/series and included our patients for survival analysis. (2) Methods: In this systematic review, we searched from PubMed-MEDLINE, EMBASE, Scopus, Cochrane Library, CINAHL, and Google Scholar for individual patient data to identify and retrieve all reported SMARCB1-deficient sinonasal carcinoma. Clarification on treatment details and the most updated survival outcomes from all authors of the published case reports/series were attempted. Survival analysis for overall survival (OS) and identification of OS prognostic factors were performed. This systematic review was registered with PROSPERO (CRD42022306671). (3) Results: A total of 67 publications were identified from the systematic review and literature search. After excluding other ineligible and duplicated publications, 192 patients reported were considered appropriate for further review. After excluding duplicates and patients with incomplete pretreatment details and survival outcomes, 120 patients were identified to have a complete set of data including baseline demographics, treatment details, and survival outcomes. Together with 8 patients treated in our institution, 128 patients were included into survival analysis. After a median follow up of 17.5 months (range 0.3-149.0), 50 (46.3%) patients died. The 1-year, 2-year and 3-year OS rates were 84.3% (95% CI % 77.6-91.0), 62.9% (95% CI 53.1-72.7), and 51.8% (95% CI 40.8-62.8), respectively, and the median OS was 39.0 months (95% CI 28.5-49.5). Males (p = 0.029) and T4b disease (p = 0.013) were significant OS prognostic factors in univariable analysis, while only T4b disease (p = 0.017) remained significant in multivariable analysis. (4) Conclusions: SMARCB1-deficient sinonasal carcinoma is an extremely aggressive sinonasal malignancy with a dismal prognosis. Early diagnosis and a multimodality treatment strategy are essential for a better treatment and survival outcome.

SMARCB1 (INI-1)-Deficient Sinonasal Carcinoma: A Case Report and Literature Review

Background: SWItch/Sucrose Non-Fermentable related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1)-deficient sinonasal carcinoma (SDSC) is a malignant tumor classified as sinonasal undifferentiated carcinoma (SNUC). Purpose: Owing to the high aggressiveness and poor prognosis reported in recent literature, patients diagnosed with SNUC should consider further immunohistochemical examination to screen for SDSC. Timely diagnosis is critical and will contribute to follow-up targeted therapy and improved patient prognosis. Research Design: Case report. Study Sample: A case of SDSC with a history of chronic sinusitis with nasal polyps (CRSwNP). Data Collection: We collected all the clinical data of this patient. Results: The patient underwent planned functional endoscopic sinus surgery (FESS) and received chemotherapy combined with immunotherapy postoperatively. There was no evidence of recurrence or metastasis at the 3-month follow-up. Conclusions: The patient in this case presented with right intermittent epistaxis, and surgical histopathological examination confirmed a diagnosis of right SDSC and left CRSwNP. No related research has been reported.

INI-1-Deficient Sinonasal Carcinoma: Case Report with Emphasis on Differential Diagnosis

SMARCB1-deficient sinonasal carcinoma is a newly described entity, with less than 100 reported cases. It is characterized by basaloid or rhabdoid morphology and is diagnosed by complete loss of nuclear SMARCB1 (INI-1). The morphologic appearance, specific immunophenotypic markers, and unique molecular make-up distinguish this entity from other various malignant neoplasms. We present a case of a 55-year-old male that presented with a large progressing palatine mass. Magnetic resonance imaging showed a heterogeneous mass involving the left maxillary space. The initial biopsy was diagnosed as undifferentiated carcinoma. Resection was performed, and immunohistochemical studies revealed a complete loss of INI-1, refining the diagnosis to SMARCB1-deficient sinonasal carcinoma. Diagnosis of SMARCB1-deficient sinonasal carcinoma should be considered in all undifferentiated sinonasal carcinomas. Immunohistochemistry or molecular studies are mandatory to confirm the diagnosis and exclude other morphologically similar entities.

Towards a Molecular Classification of Sinonasal Carcinomas: Clinical Implications and Opportunities

Simple Summary

In recent years, there have been several molecular and immunohistochemical additions to the pathologic diagnosis of sinonasal malignancies that could facilitate the identification of clinically relevant groups of sinonasal malignancies. Molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this article we review the recent literature on molecular analysis and/or subtyping of sinonasal carcinomas and we discuss the possible clinical implications of a classification of sinonasal tumors based on their molecular features.

Abstract

Sinonasal carcinomas are a heterogeneous group of rare tumors, often with high-grade and/or undifferentiated morphology and aggressive clinical course. In recent years, with increasing molecular testing, unique sinonasal tumor subsets have been identified based on specific genetic alterations, including protein expression, chromosomal translocations, specific gene mutations, or infection by oncogenic viruses. These include, among others, the identification of a subset of sinonasal carcinomas associated with HPV infection, the identification of a subset of squamous cell carcinomas with EGFR alterations, and of rare variants with chromosomal translocations (DEK::AFF2, ETV6::NTRK and others). The group of sinonasal adenocarcinomas remains very heterogeneous at the molecular level, but some recurrent and potentially targetable genetic alterations have been identified. Finally, poorly differentiated and undifferentiated sinonasal carcinomas have undergone a significant refinement of their subtyping, with the identification of several new novel molecular subgroups, such as NUT carcinoma, IDH mutated sinonasal undifferentiated carcinoma and SWI/SNF deficient sinonasal malignancies. Thus, molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this review, we summarize the recent developments in the molecular characterization of sinonasal carcinomas and we discuss how these findings are likely to contribute to the classification of this group of rare tumors, with a focus on the potential new opportunities for treatment.

Clinical diagnosis and treatment analyses on SMARCB1 (INI-1)-deficient sinonasal carcinoma: case series with systematic review of the literature

OBJECTIVE

This study aims to improve the understanding of SMARCB1 (INI-1)-deficient sinonasal carcinoma (SDSC) by analyzing its clinical features, treatment strategies and prognosis.

METHODS

Sixty-nine patients were included in this research: 15 new cases from Beijing Tongren Hospital, and 54 previously reported cases. We analyzed and summarized patients' epidemiological data, clinical features, and treatment regimens. Main outcomes were overall survival (OS) and recurrence-free survival (RFS). Univariate and multivariate analyses were performed using a Cox regression model for OS and RFS.

RESULTS

SDSC was more common in men than womanwith a median age of 52 (ranged from 21 to 89 years). Epistaxis (40.0%) and headache (36.7%) were the major complaints. The most common affected paranasal sinus was the ethmoid sinus (58.0%). For TNM stage, 66.7% cases were first diagnosed as T4N0M0. The tumor cells were complete loss of INI-1 in all cases by immunohistochemical analysis. However, 72.5% cases were first misdiagnosed initially. The 1-year, 3-year, and 5-year OS and RFS were 85.3%, 51.8%, 47.8%; and 56.8%, 38.2%, 35.3% respectively. The RFS of comprehensive treatment based on surgery was better than that of systemic therapy without surgery (P<0.05), Additionally, the OS and RFS of surgery with chemoradiotherapy was better than that of surgery with radiotherapy (P<0.05). Univariate and multivariate analysis identified treatment modality as an independent prognostic factor for SDSC patients.

CONCLUSION

Immunohistochemical analysis of SDSC during initial biopsy can prevent delays in diagnosis and treatment. Radical surgery resection combined with chemoradiotherapy may be the preferred treatment modality.

Primary Thyroid NUT Carcinoma With High PD-L1 Expression and Novel Massive IGKV Gene Fusions: A Case Report With Treatment Implications and Literature Review

Background

Nuclear protein in testis (NUT) carcinoma (NC) is a rare and aggressive undifferentiated carcinoma that typically arises from midline supradiaphragmatic structures. It is uniquely driven by a NUT gene rearrangement on chromosome 15q14. Few thyroid NCs have been reported and there are no established treatment guidelines for NUT carcinoma.

Method

Ultrasound-guided fine needle aspiration smear was performed for the preoperative diagnosis of thyroid lesions. Cytopathology, histology, and immunochemical staining all indicated NC. Fluorescence in situ hybridization (FISH), qRT-PCR, and next-generation sequencing (NGS) were used to analyze the genetic characteristics of NC.

Results

We describe a rare case of thyrogenic NC in a 38-year-old male with cytological, histological, immunohistochemical, and genetic features. Cytological smears and histopathological specimens showed typical features of NC. Immunohistochemistry confirmed strong immunoreactivity with NUT, EMA, P63, TTF-1, and c-myc. CK19 was positive exclusively in sudden keratosis. No immunoreactivity was found for neuroendocrine markers. FISH was applied to isolate the NUT gene on chromosome 15q14. The NGS results revealed a BRD4-NUT gene fusion, which was further confirmed by RT-qPCR. Structural variation (SV) of NUTM1 occurred in the exon region, and the mutation site was 15q14. Moreover, BRD4 single-nucleotide variation (SNV) occurs in the 3′ UTR at mutation site 19p13.12. The PD-L1 combined predictive score was over 30%. The patient received chemotherapy, followed by programmed cell death 1 (PD-1) inhibition with camrelizumab, and died 10 months after surgery.

Conclusion

Thyroid NC is an extremely rare and fatal malignant tumor. It is necessary to consider NC when squamous differentiation is observed cytologically or histologically. NGS is an effective tool for obtaining the final diagnosis and obtaining a better understanding of tumor pathogenesis. A large number of IGKV gene fusions in addition to the BRD4-NUT fusion may play a role in the pathogenesis and immunotherapy response of NC. Immunotherapy for NC remains to be explored due to the rarity of this aggressive malignancy.

SMARCB1(INI1)-deficient sinonasal adenocarcinoma: Report of a case previously diagnosed as high-grade non-intestinal-type sinonasal adenocarcinoma

SMARCB1(INI1)-deficient sinonasal carcinoma is a recently recognized entity with wide histomorphologic spectrum. The classification of sinonasal adenocarcinoma (SNAC) is complex and yet to be redefined, especially the category of high-grade non-intestinal-type SNAC. Recently SMARCB1(INI1)-deficient SNACs with an unique oncocytoid/rhabdoid cytomorphology and variable degrees of glandular formation have been reported. Here we described a rare case of SMARCB1(INI1)-deficient SNAC composed of mainly oncocytoid/rhabdoid cells with mixed solid and cribriform patterns. This case was originally diagnosed as non-intestinal-type SNAC and was reclassified due to complete loss expression of SMARCB1(INI1) by immunohistochemistry (IHC). The SMARCB1(INI1) stain provides a valuable tool for identification of this specific type of SNAC. We compared this case with other SNACs diagnosed in our department and reviewed relevant literature for this specific type of SNAC.

Sinonasal SMARCB1 (INI1) Deficient Carcinoma with Yolk Sac Tumor Differentiation: A Case Report and Treatment Options

SMARCB1 (INI1) deficient carcinoma (SDC) is a newly-described, aggressive, high-grade malignancy of the adult population. Rarely, these tumors demonstrate yolk sac differentiation. Treatment protocols are not defined due to the rarity of this entity. A 55 year-old-male presented with a tumor originating in the maxillary sinus. He was treated with neoadjuvant therapy followed by radical surgery and adjuvant treatment. We review the literature and discuss the course of disease and treatments of sinonasal SDC with yolk sac tumor differentiation. To our knowledge, this is the sixth reported case of sinonasal SDC with yolk sac tumor differentiation. This is the first publication describing the clinical course and efficacy of therapeutic interventions.

Case Report: SMARCB1 (INI-1)-Deficient Carcinoma of the Nasal Cavity with Pure Yolk Sac Tumor Differentiation and Elevated Serum AFP Levels

In adults, yolk sac tumors (YSTs) in the nasal cavity and paranasal sinuses are very rare. To date, only six cases have been reported in the English literature. YSTs in adults are often accompanied by cancer, teratocarcinosarcoma, and other malignant components. Here, we have reported a case of nasal tumor in a 55-year-old man with nasal obstruction and epistaxis. Morphologically, the tumor showed histological characteristics of pure YST. Immunohistochemical staining showed diffuse expression of SALL4, CDX2, and GPC-3 accompanied by sporadic expression of alpha-fetoprotein (AFP) and CD117. After 20 and 40 days of operation, the serum AFP level was 220.30 and 43.60 ng/mL (normal, <7 ng/mL), respectively, which supported the pathological diagnosis of YST. However, we further performed immunohistochemical staining and fluorescence in situ hybridization using an INI-1 probe to detect the status of INI-1 in tumor cells. The results revealed that INI-1 was absent in tumor cells. Hence, we corrected the diagnosis to SMARCB1 (INI-1)-deficient carcinoma of the nasal cavity with YST differentiation. The patient underwent surgery and adjuvant radiotherapy in our hospital without evidence of recurrence or metastasis at the 6-month follow-up. The serum AFP level had also normalized. In conclusion, our case demonstrates that INI-1-deficient carcinoma may exhibit, a pure YST differentiation and immunophenotype, and elevated serum AFP levels. In adults, YST in the nasal cavity may represent INI-1-deficient carcinoma, which may be a potential diagnostic pitfall.