NUT midline carcinoma of the head and neck: current perspectives

[Research Progress on Pathogenesis and Treatment of NUT Carcinoma]

NUT carcinoma (nuclear protein in testis carcinoma) is a rare and highly invasive malignant tumor, which is most common in midline organs and lungs. The characteristic genetic change of NUT carcinoma is the rearrangement of NUT middle carcinoma family member 1 (NUTM1) gene. In this article, we will review the pathogenic mechanism of its most common fusion form, bromodomaincontaining protein 4 (BRD4)-NUTM1 fusion gene, and the progress in the research and development of targeting drugs.
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A case of fine-needle aspiration of a neck mass with atypical squamous cells and macrophages

Head and neck lesions often undergo fine-needle aspiration to determine the appropriate management and therapeutic decisions. However, there are numerous diagnostic challenges encountered with these specimens, particularly, if atypical squamous cells are identified. Here, we present a case of an enlarging right neck mass in a 38-year-old female and discuss the diagnostic difficulties and potential pitfalls. Additionally, we review the approach to diagnosis, including differential diagnostic considerations as well as available ancillary testing.

Immunotherapy experience in sinonasal NUT midline carcinoma, case report

NUT midline carcinoma (NMC) is an aggressive malignant neoplasm arising from midline structures. Although it is classified as a rare disease, the pathological nonspecific appearance as undifferentiated/poorly differentiated carcinoma and the difficulty in making the definitive diagnosis are probably the reasons for the underdiagnosis; the disease is thought to be more prevalent. There is no standard treatment for the disease. The disease shows a poor response to chemotherapy and radiotherapy, and patients' survival is poor. We present a case of sinonasal NMC treated with chemotherapy and immunotherapy in first-line, which is the first in the literature. The patient presented with metastatic disease and received cisplatin-fluorouracil-docetaxel-pembrolizumab treatment. The tumor's PD-L1 expression was 10%, evaluated by tumor proportion score. The response to the therapy was poor, and the patient died of disease progression 5.4 months after the diagnosis. The efficacy of immunotherapy in NMC is not known. More reports are needed to draw conclusions.

Sinonasal NUT carcinoma: A consecutive case series and systematic review

BACKGROUND

Sinonasal NUT carcinoma is an extremely rare, lethal malignancy with limited literature.

METHODS

A case series was conduction of all patients with sinonasal NUT carcinoma at a single institution between 2010 and 2022. Survival and associated were evaluated. A systematic review of the literature was performed.

RESULTS

In 12 patients, followed for a median of 1.5 years, the median overall survival (OS) and disease-specific survival (DSS) were both 14.6 months. Patients with maxillary sinus tumors were 91% more likely to survive (hazard ratio [HR]: 0.094, 95% confidence interval [CI]: 0.011-0.78, p = 0.011). Patients with higher-stage disease stage had worse OS (stage IVb-c vs. III-IVa, p = 0.05). All three patients who were alive with no evidence of disease received induction chemotherapy.

CONCLUSION

For patients with sinonasal NUT carcinoma, the median survival was 15 months but better with lower-stage and maxillary tumors. Induction chemotherapy may be beneficial.

Current Approach to Undifferentiated Neoplasms, With Focus on New Developments and Novel Immunohistochemical Stains

CONTEXT.—

Workup of the poorly differentiated or undifferentiated tumor remains a significant and challenging entity in the practice of anatomic pathology. Particularly in the setting of small biopsies and limited material, these cases demand a balanced approach that considers the patient's clinical and radiologic presentation, a basic assessment of tumor morphology, a reasonably broad immunohistochemical panel, and diligent preservation of tissue for prognostic and therapeutic studies.

OBJECTIVE.—

To illustrate some of the new and emerging immunohistochemical markers in the evaluation of tumors with undifferentiated or poorly differentiated morphology, with a focus on the workup in limited tissue samples to raise awareness of the issues involved with the pathologic workup in these challenging tumors.

DATA SOURCES.—

A literature review of new ancillary studies that can be applied to cytologic specimens was performed.

CONCLUSIONS.—

Knowledge of the patient's history and communication with the patient's clinical team is essential in formulating a differential diagnosis that can appropriately limit the differential diagnosis based on morphology, especially in small specimens. This information, in conjunction with classifying the tumor morphology (eg, epithelioid, spindled, neuroendocrine, basaloid/biphasic, mixed) gives a logical approach to choosing an initial immunohistochemical panel. Fortunately, immunohistochemistry is evolving quickly in the wake of groundbreaking molecular studies to develop new and better markers to further classify these difficult tumors beyond where we traditionally have been able to go.

Primary pulmonary NUT midline carcinoma: An elusive and a rare diagnostic entity

Nuclear protein in testis (NUT) midline carcinoma is a poorly differentiated tumor, is more common in midline anatomic sites, and involves young adults and children mainly. Primary pulmonary NUT midline carcinoma (NMC) is a rare and poorly defined entity in the prevailing literature. Being a highly aggressive and fatal neoplasm, it gets incumbent for the oncologists and the pathologists to be aware of this entity as it holds distinct management protocol and prognosis. Currently, BET inhibitors (BETi) and histone deactylase inhibitors have shown promising results as targeted therapies in clinical trials in head and neck NMC. We present a case report of NMC of primary pulmonary location in a young male with widespread bony metastasis.

Nuclear protein in testis carcinoma of the lung

Nuclear protein in testis (NUT) carcinoma is a kind of highly aggressive and fatal solid tumor characterized by a rearrangement of the NUT carcinoma family member 1 (NUTM1) gene located on chromosome 15 q l4, where the most common form of fusion is BRD4-NUT. NUT carcinoma occurred in different organs and was most commonly found in the midline organs and the lungs. NUT carcinoma can occur in patients of almost all ages, having a roughly consistent incidence in both sexes. Most of the patients were diagnosed in advanced stages with an extremely poor prognosis due to the lack of effective treatment. After years of research, the mechanism of NUT carcinoma is still not fully clear, and its therapeutic approaches need to be further studied and explored. In order to gain a more comprehensive understanding of NUT carcinoma and explore the effective treatments, this review aimed to summarize the clinical features, pathological characteristics, differential diagnosis, and treatment strategies for this disease.

The contemporary management of cancers of the sinonasal tract in adults

Sinonasal malignancies make up <5% of all head and neck neoplasms, with an incidence of 0.5-1.0 per 100,000. The outcome of these rare malignancies has been poor, whereas significant progress has been made in the management of other cancers. The objective of the current review was to describe the incidence, causes, presentation, diagnosis, treatment, and recent developments of malignancies of the sinonasal tract. The diagnoses covered in this review included sinonasal undifferentiated carcinoma, sinonasal adenocarcinoma, sinonasal squamous cell carcinoma, and esthesioneuroblastoma, which are exclusive to the sinonasal tract. In addition, the authors covered malignances that are likely to be encountered in the sinonasal tract-primary mucosal melanoma, NUT (nuclear protein of the testis) carcinoma, and extranodal natural killer cell/T-cell lymphoma. For the purpose of keeping this review as concise and focused as possible, sarcomas and malignancies that can be classified as salivary gland neoplasms were excluded.

Multimodality imaging and treatment of paranasal sinuses nuclear protein in testis carcinoma: A case report

BACKGROUND

Nuclear protein in testis (NUT) carcinoma is a rare aggressive malignant epithelial cell tumor, previously known as NUT midline carcinoma (NMC), characterized by an acquired rearrangement of the gene encoding NUT on chromosome 15q14. Due to the lack of characteristic pathological features, it is often underdiagnosed and misdiagnosed. A variety of methods can be used to diagnose NMC, including immunohistochemistry, karyotyping, fluorescence in situ hybridization, reverse transcription-polymerase chain reaction, and next-generation sequencing. So far, there is no standard treatment plan for NMC and the prognosis is poor, related to its rapid progression, easy recurrence, and unsatisfactory treatment outcome.

CASE SUMMARY

A 58-year-old female came to our hospital with a complaint of eye swelling and pain for 8 d. The diagnosis of NMC was confirmed after postoperative pathology and genetic testing. The patient developed nausea and vomiting, headache, and loss of vision in both eyes to blindness after surgery. Magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) performed after 1.5 mo postoperatively suggested tumor recurrence. The patient obtained remission after radiation therapy to some extent and after initial treatment with anti-angiogenic drugs and sonodynamic therapy (SDT), but cannot achieve long-term stability and eventually developed distant metastases, with an overall survival of only 17 mo.

CONCLUSION

For patients with rapidly progressing sinus tumors and poor response to initial treatment, the possibility of NMC should be considered and immunohistochemical staining with anti-NUT should be performed as soon as possible, combined with genetic testing if necessary. CT, MRI, and PET/CT imaging are essential for the staging, management, treatment response assessment and monitoring of NMC. This case is the first attempt to apply heat therapy and SDT in the treatment of NMC, unfortunately, the prognosis remained poor.

Supraglottic NUT Carcinoma: A Case Report and Literature Review

Nuclear protein of the testis (NUT) carcinoma is a very rare cancer that occurs in relatively young patients. In this study, we experienced a case of laryngeal NUT carcinoma that followed a rapid course. A 22-year-old woman was diagnosed with supraglottic squamous cell carcinoma, cT3N2bM0. She underwent chemoradiotherapy (CRT) (total dose, 70 Gy; 2 Gy × 35 Fr; 80 mg/m² every 3 weeks with CDDP) as a curative treatment and achieved a complete response. However, 3 weeks after the completion of CRT, she presented to the outpatient clinic complaining of abdominal pain. Magnetic resonance imaging revealed a huge neoplastic lesion in the right ovary. Abdominal right adnexal resection plus partial retreatment was performed. The pathology of ovarian tumor was poorly differentiated squamous cell carcinoma, and NUT protein was positive. The laryngeal carcinoma was also positive for NUT protein; therefore, we diagnosed ovarian tumor is metastasis from supraglottic carcinoma. Peritoneal dissemination was observed in the early postoperative period. She was refractory to subsequent chemotherapy and had a rapid progression. Subsequently, CT showed further thickening of the peritoneum, increased ascites, and increased metastases. She died 32 weeks after initial diagnosis and 14 weeks after abdominal surgery. NUT carcinoma is difficult to diagnose without suspicion. Therefore, the possibility of NUT carcinoma should be considered in young patients with laryngeal carcinoma.

NUT Carcinoma in Children and Adolescents: The Expert European Standard Clinical Practice Harmonized Recommendations

BACKGROUND AND AIMS

Nuclear protein of the testis (NUT) carcinoma (NC) is a rare and highly aggressive tumor mainly occurring in adolescents and young adults, defined by the presence of a somatic NUTM1 rearrangement. The aim is to establish internationally harmonized consensus recommendations for the diagnosis and treatment of adolescents and young adults with NC in the framework of the European Reference Network for Paediatric Oncology.

METHODS

The European Cooperative Study Group for Pediatric Rare Tumors developed recommendations according to the Consensus Conference Standard Operating procedure methodology and reviewed by external "experts." No evidence of level I to II exists. Recommendations were developed based on published prospective (level III), but more frequently retrospective series (level IV), case reports (level V), and personal expertise (level V). In addition, "strength" of recommendations were categorized by grading (grade A to E).

RESULTS

Histology is mandatory for the diagnosis of NC, including immunolabeling with anti-NUT antibodies and molecular biology (NUTM1 rearrangement) (level V; grade A). Treatment of NC usually combines aggressive approaches in multimodal regimens. Chemotherapy should be considered as first-line treatment (neoadjuvant vincristine-adriamycin-ifosfamide/cisplatin-adriamycin-ifsofamide or vincristine-doxorubicin-cyclophosphamide/ifosfamide-etoposide) for unresectable or metastatic tumor (ie, 3 courses), rapidly followed by local treatment (level IV; grade B). Referral to a specialized surgical oncology center is highly recommended (level V; grade A). In localized NC, a complete microscopic surgical resection should be attempted whenever and as soon as possible, followed by primary irradiation (60 to 70 Gy) and involved lymph nodes area (level IV; grade B). For head and neck tumors, a systematic neck dissection might be considered, even if N0 (level V; grade C). Adjuvant postirradiation chemotherapy is recommended, for a total of 9 to 12 courses (level IV; grade B). For first-line resected tumors, concomitant adjuvant chemotherapy to radiotherapy may be discussed (level IV; grade B). Targeted therapies and immunotherapeutic regimens should be delivered in the setting of prospective trials (level V; grade B).

CONCLUSIONS

This project leads to a consensus strategy based on international experience with this very rare disease.

Possible Primary Thyroid Nuclear Protein in Testis Carcinomas with NSD3::NUTM1 Translocation Revealed by RNA Sequencing: A Report of Two Cases

Background: Nuclear protein in testis (NUT) carcinomas (NC) are a rare, highly aggressive, subset of squamous cell carcinomas, characterized by a translocation involving the NUTM1 gene. Thyroid location of NUT carcinomas has rarely been described. Methods: We report here two cases of thyroid NC with NSD3::NUTM1 translocation. Results: The first case presented as a very aggressive undifferentiated thyroid carcinoma in a 38-year-old man who died 21 months after the diagnosis. The second case was diagnosed after multiple lymphadenopathy recurrences mainly in the neck in a 37-year-old woman 7 years after total thyroidectomy for papillary thyroid carcinoma with a classic and a solid/trabecular component. Conclusions: Our case reports highlight the challenges in diagnosing these exceptional carcinomas. The therapeutic impact of the administration of pharmacological compounds with epigenetic action, in line with the physiopathology of these carcinomas, is also discussed.

Unclassified Neuroendocrine Tumor with a Novel CHD4::AFF2 Fusion: Expanding the Family of AFF2-Rearranged Head and Neck Malignancies

The past decade has seen a dramatic increase in the number of new head and neck tumor entities, most of which are genetically defined. DEK::AFF2 carcinoma is one of the most recently defined neoplasms; it shows a non-keratinizing squamous morphology and occurs in the sinonasal region. We present an unusual neoplasm that was found to harbor a novel fusion involving AFF2. The case was encountered in our clinical practice. Immunohistochemistry was performed along with targeted next generation sequencing (NGS). The case presented as a metastasis to a cervical lymph node from an unknown primary, in a 49-year-old man. The tumor consisted of sheets of primitive round cells which were strongly positive for synaptophysin and chromogranin but negative for cytokeratins, S-100 protein, WT-1, desmin, and many other markers. NGS uncovered CHD4::AFF2. We found a CHD4::AFF2 fusion in a high-grade neuroendocrine tumor. Although it is just a single case, the presence of a novel fusion in a neoplasm that is otherwise not classifiable suggests that it could be a distinct entity within a possible family of AFF2-rearranged tumors. Molecular analysis should be considered for any unclassified round cell tumor in the head and neck, as additional cases will be needed to further elucidate this area.

NUT Carcinoma—An Underdiagnosed Malignancy

NUT carcinoma (NC) is a rare and highly aggressive malignancy with a dismal prognosis and a median survival of 6–9 months only. Although very few cases of NC are reported each year, the true prevalence is estimated to be much higher, with NC potentially widely underdiagnosed due to the lack of awareness. NC primarily occurs in midline structures including thorax, head, and neck; however, other sites such as pancreas and kidney are also affected, albeit at lower frequencies. NC is characterized by a single translocation involving the NUTM1 (NUT midline carcinoma family member 1) gene and different partner genes. The resulting fusion proteins initiate tumorigenesis through a mechanism involving BET (bromo-domain and extra-terminal motif) proteins such as Bromodomain-containing protein 4 (BRD4) and inordinate acetylation of chromatin, leading to the dysregulation of growth and differentiation genes. While no clinical characteristics are specific for NC, some histologic features can be indicative; therefore, patients with these tumor characteristics should be routinely tested for NUTM1. The diagnosis of NC using immunohistochemistry with a highly specific antibody is straightforward. There are currently no standard-of-care treatment options for patients with NC. However, novel therapies specifically addressing the unique tumorigenic mechanism are under investigation, including BET inhibitors. This review aims to raise awareness of this underdiagnosed cancer entity and provide all patients the opportunity to be properly diagnosed and referred to a clinical study.

NUT Carcinoma: Clinicopathologic Features, Molecular Genetics and Epigenetics

Nuclear protein in testis (NUT) carcinoma is a rare, highly aggressive, poorly differentiated carcinoma occurring mostly in adolescents and young adults. This tumor usually arises from the midline structures of the thorax, head, and neck, and exhibits variable degrees of squamous differentiation. NUT carcinoma is defined by the presence of a NUTM1 (15q14) rearrangement with multiple other genes. In about 70-80% of the cases, NUTM1 is involved in a balanced translocation with the BRD4 gene (19p13.12), leading to a BRD4-NUTM1 fusion oncogene. Other variant rearrangements include BRD3-NUTM1 fusion (~15-20%) and NSD3-NUTM1 fusion (~6%), among others. The diagnosis of NUT carcinoma requires the detection of nuclear expression of the NUT protein by immunohistochemistry. Additional methods for diagnosis include the detection of a NUTM1 rearrangement by fluorescence in situ hybridization or by reverse transcriptase PCR. NUT carcinoma is usually underrecognized due to its rarity and lack of characteristic histological features. Therefore, the goal of this review is to provide relevant recent information regarding the clinicopathologic features of NUT carcinoma, the role of the multiple NUTM1 gene rearrangements in carcinogenesis, and the impact of understanding these underlying molecular mechanisms that may result in the development of possible novel targeted therapies.

Intra-, para-, and suprasellar nuclear protein of testis carcinoma with infiltration of cavernous sinus and clivus-a case report

A nuclear protein of testis (NUT) carcinoma, also known as NUT midline carcinoma, is a rare subtype of squamous carcinoma known for its aggressive growth behaviour. It can form anywhere in the body. Although, it usually occurs along midline structures (head, neck, lungs). The authors present the first report of intrasellar NUT carcinoma with cavernous sinus infiltration in a 47-year-old patient. MRI showed an inhomogeneous, gadolinium-enhancing lesion with intra- and suprasellar growth, invasion of the cavernous sinus without clear differentiation from normal pituitary tissue. Given the lymphoma diagnosis in the frozen section and invasion of the cavernous sinus, the patient underwent endoscopic, transnasal, and transsphenoidal subtotal resection only. Local tumour and spinal metastases showed a good response to radio-chemotherapy. Despite combined radio-chemotherapy, the patient died of pulmonary insufficiency due to rapid progression of pulmonary metastasis 6 months after the initial diagnosis.

Measuring the Patient Experience in Rare Disorders: Benefit of Pragmatic Mixed-Methods Research in NUT Carcinoma

Introduction

Patient-centered outcome measurement (PCOM) is essential to capture the outcomes important to patients. However, it presents unique challenges in rare diseases, particularly those that are “young” (not diagnosed before the twenty-first century), with limited literature, lack of disease-specific patient-reported outcome (PRO) measures, and difficult sampling and data collection. One example of this is NUT (nuclear protein in testis) carcinoma (NUTca), a rare and rapidly progressing cancer, with tumors preliminary in the head, neck, and lungs. The published literature on NUTca is scarce. The limited number of case reports focus primarily on the clinical development and presentation of tumors. Currently, there are no publications describing the patient experience of NUTca and no specific PRO measures to assess the patient experience. We conducted mixed-methods research, including concept elicitation interviews, cognitive debriefing, and quantitative data analyses, to fill this evidence gap and describe challenges and solutions in the context of NUTca.

Methods

As published previously, our conceptualization of NUTca was based on elicitation interviews with 27 participants (n = 10 patients; n = 17 caregivers) using a semi-structured format; this framework formed the basis for a bolt-on strategy to develop a bespoke PRO measure based on the EORTC QLQ-C30, supplemented by targeted items from the EORTC Item Library and new items. In this publication, 20 participants were interviewed (n = 10 patients; n = 10 caregivers) to debrief items. Given the variety of tumor locations and related symptoms, and the small sample of patients providing responses to location-specific symptom items, we used response option endorsement frequencies to illuminate the variability of response for the concepts measured.

Results

This study highlights the challenges in implementing patient-centric research to inform and develop PRO measures in rare diseases.

Conclusions

Our mixed-methods research used pragmatic solutions to collect patient experience data and provides an evidence base to inform PCOM in clinical programs in this rapidly progressing rare cancer with high unmet need.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40487-022-00192-6.

Understanding the Patient Experience in NUT Carcinoma: Qualitative Interviews with Patients and Caregivers to Develop a Conceptual Framework

INTRODUCTION

NUT (nuclear protein of the testis) carcinoma (NUTca) is a rare and aggressive cancer that is genetically hallmarked by a chromosomal abnormality in the NUT gene, and presents with tumors in the head, neck, and lungs. Currently there is no standard of care, but patients may undergo surgery, radiation, and/or chemotherapy. There is a lack of published research describing the patient experience of NUTca. The objective of this study was to develop a conceptual framework (CF) that describes patients' experience of NUTca to inform the selection of outcome measures and design of patient-centric endpoints for future clinical research.

METHODS

Individual, semi-structured telephone interviews were conducted with patients and caregivers of patients who have/had NUTca (caregivers interviewed due to recruitment challenges resulting from the rarity of NUTca). Participants were asked about their disease symptoms, impacts, and treatment experience. Interviews were audio-recorded, transcribed, and analyzed using inductive coding. The CF was developed through inductive categorization of concepts, sub-domains, and domains.

RESULTS

Twenty-seven interviews were completed (patients n = 10; caregivers n = 17). Participants reported systemic symptoms (e.g., fatigue) and symptoms related to the location of the tumor (e.g., nose blockage for head/neck tumor). Pain emerged as an important and bothersome symptom across tumor locations. Participants reported impacts on their daily activities (e.g., showering), emotions (e.g., preoccupation), sleep, social life (e.g., isolation), roles (e.g., caring for children), and finances. The final CF was organized into four symptom domains [systemic, location-specific (head/neck, lung), pain, and digestive] and six impact domains (daily activities, emotional, sleep, social, role, and financial).

CONCLUSIONS

This study describes the patient experience of NUTca and proposes an evidence-based CF that informs both the clinical community's understanding of the disease and selection of a patient-reported outcome (PRO) measure to assess treatment benefit in future NUTca trials.

Immunotherapy and Targeting the Tumor Microenvironment: Current Place and New Insights in Primary Pulmonary NUT Carcinoma

Primary pulmonary nuclear protein of testis carcinoma is a rare and highly aggressive malignant tumor. It accounts for approximately 0.22% of primary thoracic tumors and is little known, so it is often misdiagnosed as pulmonary squamous cell carcinoma. No effective treatment has been formed yet, and the prognosis is extremely poor. This review aims to summarize the etiology, pathogenesis, diagnosis, treatment, and prognosis of primary pulmonary nuclear protein of testis carcinoma in order to better recognize it and discuss the current and innovative strategies to overcome it. With the increasing importance of cancer immunotherapy and tumor microenvironment, the review also discusses whether immunotherapy and targeting the tumor microenvironment can improve the prognosis of primary pulmonary nuclear protein of testis carcinoma and possible treatment strategies. We reviewed and summarized the clinicopathological features of all patients with primary pulmonary nuclear protein of testis carcinoma who received immunotherapy, including initial misdiagnosis, disease stage, immunohistochemical markers related to tumor neovascularization, and biomarkers related to immunotherapy, such as PD-L1 (programmed death-ligand 1) and TMB (tumor mutational burden). In the meanwhile, we summarized and analyzed the progression-free survival (PFS) and the overall survival (OS) of patients with primary pulmonary nuclear protein of testis carcinoma treated with PD-1 (programmed cell death protein 1)/PD-L1 inhibitors and explored potential population that may benefit from immunotherapy. To the best of our knowledge, this is the first review on the exploration of the tumor microenvironment and immunotherapy effectiveness in primary pulmonary nuclear protein of testis carcinoma.

Skin adnexal carcinoma with BRD3-NUTM2B fusion

NUT carcinomas are genetically defined epithelial neoplasms. Most tumors harbor fusions of NUTM1 with BRD4 or BRD3. Their histopathologic features have been predominantly reported as undifferentiated or poorly differentiated squamous cell carcinoma, and clinically they tend to be aggressive cancers. However, recent studies have revealed a broader spectrum of NUTM1-rearranged neoplasms with several new fusion partners and associated variable histopathologic phenotypes and clinical behaviors, including benign and malignant cutaneous poroid tumors. We report herein a primary invasive carcinoma of skin adnexal origin with a previously undescribed fusion between BRD3 and NUTM2B. The tumor occurred on the shoulder of a 7-year-old girl and was excised with negative margins. A sentinel lymph node was positive. After follow-up of 23 months, and without systemic treatment, the child remains free of tumor. This case expands the spectrum of NUT carcinomas by including a skin adnexal variant with follicular infundibular differentiation, a novel genomic aberration, and preliminary evidence of a less aggressive clinical course.

Diagnostic discrepancy in second opinion reviews of primary epithelial neoplasms involving salivary gland: An 11-year experience from a tertiary referral center focusing on useful pathologic approaches and potential clinical impacts

AIMS

In the era of precision medicine, accurate pathologic diagnoses are crucial for appropriate management.

METHODS

We herein described the histologic features and clinical impacts of 66 salivary gland epithelial neoplasms in which the diagnosis was altered after expert review.

RESULTS

The most common revised diagnosis was that of salivary duct carcinoma (SDC, n = 12), adenoid cystic carcinoma (n = 12), and myoepithelial carcinoma (n = 10). The most common initial diagnosis was mucoepidermoid carcinoma (n = 19) with SDC being the most common revised diagnosis (7/19). Thirteen salivary gland carcinomas were initially diagnosed as benign entities, whereas five benign tumors were initially interpreted as carcinoma. The change in diagnosis was considered to be clinically significant in 65 (97%) cases.

CONCLUSIONS

Given their rarity, salivary gland neoplasms are prone to diagnostic inaccuracy and discrepancy. A constellation of histologic features and ancillary studies are useful in reaching the correct diagnosis, which can have significant clinical impacts.

Sinonasal NUT Carcinoma: Delayed Diagnosis Due to the COVID-19 Pandemic and a Review of the Literature

NUT carcinoma (NUT-C) is a relatively new malignancy that was recently listed in the 4th edition of the WHO Classification of Head and Neck Tumors in 2017. NUT carcinoma is a rare, aggressive, poorly differentiated carcinoma genetically defined by chromosomal rearrangement of the nuclear protein in testis (NUTM1) gene. The prognosis is extremely poor, with a mean survival < 1 year. Recent publications suggest a multimodality treatment approach. In the existing literature, only a few reports of sinonasal NUT-C have been reported. Sinonasal NUT-C is considered a very rare entity, but because of its recent inclusion as a head and neck malignancy, its true prevalence is unknown. We report the case of a 56-year-old woman with NUT-C of the sinonasal cavities. In the case reported, the coexistence of Coronavirus disease 2019 (COVID-19)-related nasal congestion delayed the diagnosis of NUT-C. Clinical presentation, diagnosis and treatment modalities are discussed together with a review of the literature.

NUT Carcinoma Arising from the Parotid Gland: A Case Report and Review of the Literature

NUT carcinoma is an aggressive carcinoma with an overall poor survival outcome. The mediastinum and head and neck area, especially the sinonasal region, are among the common sites of disease. Histopathological diagnosis of NUT carcinoma is often very challenging due to its overlapping features with other poorly differentiated carcinomas. We report a case of NUT carcinoma arising from the parotid gland of a young female patient. Primary NUT carcinoma of salivary gland is very rare, with only 15 such cases reported in the literature to date. Our case highlights the diagnostic challenges associated with such lesions.

P63-negative pulmonary NUT carcinoma arising in the elderly: a case report

Background

Pulmonary NUT carcinoma is rare, but lethal, thus, must not be overlooked. The definitive diagnosis is made by a NUT monoclonal antibody or gene analysis, but these are not always routinely available. Therefore, the diagnosis depends on this rare disease being suspected from the clinical and pathological findings. Generally, NUT carcinoma of the lung occurs near the hilum in younger adults with severe subjective symptoms. Histologically, it is characterized by the monomorphic growth of small cells which showed positivity of p63 immunohistochemistry.

Case presentation

An 82-year-old man was referred for an incidental finding of an abnormal shadow at the peripheral apex of the right lung on computed tomography for a regular follow-up examination of renal cancer. Microscopically, small cell carcinoma was initially suspected; however, immunohistochemistry was not typical. NUT carcinoma with BRD4-NUT fusion was ultimately diagnosed using a NUT monoclonal antibody, fluorescence in situ hybridization, and RNA-seq. p63 and p40 protein expression was not detected.

Conclusions

This is the first case of pulmonary NUT carcinoma to show negativity for p63 and is the oldest among previously reported cases. The present case suggests that NUT carcinoma should be suspected when the morphology of monomorphic growth of small cells without lineage-specific differentiation, regardless of age, clinical symptoms, the tumor location, or p63 expression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-020-01053-4.

Sinonasal NUT midline carcinoma: A new histological entity

Nuclear protein in testis (NUT) midline carcinoma is poorly differentiated carcinoma defined by rearrangement of NUT gene on 15 to other genes, usually BRD4 on 19. It is first described in 1991. These tumors are most commonly seen in the mediastinum and 35% occur in head and neck. It is a highly aggressive tumor with a median survival of 7 months because of ineffective chemotherapy and undefined treatment. Hence, we must differentiate these tumors from other poorly differentiated tumors. Here, we present a case of NUT midline carcinoma of 44-year male, who presented with headache and dizziness, confirmed by immunohistochemistry of NUT antibody. The aim of this case report is to increase the awareness about this entity in adults with brief review of relevant literature.

NUT Carcinoma in a Patient with Unusually Long Survival and False Negative FISH Results

Nuclear protein in testis (NUT) carcinoma is a rare and highly aggressive epithelial malignancy defined by rearrangement of the NUTM1 gene on chromosome 15q14. Histologically, NUT carcinoma is an undifferentiated carcinoma formed by sheets and nests of primitive and monotonous "round blue cells" with foci of abrupt keratinization in a subset. NUT carcinoma runs a fulminant clinical course and is almost always quickly lethal, with a median overall survival of only 6.7 months. There is no consensus regarding treatment for this disease, and most patients respond poorly to conventional chemotherapy and radiation. We report a case of NUT carcinoma in an African-American man who initially presented in 2009 with a tracheal mass at age 28. Although fluorescence in situ hybridization (FISH) assays for NUTM1 and BRD4 rearrangements were negative, he was diagnosed based on diffusely positive NUT immunostaining and BRD4-NUTM1 on RNA sequencing. Since his initial presentation, he has undergone multiple surgical procedures and radiation therapy. His tumor has recurred twice, but he has survived for 129 months and is currently alive without disease. Long-term survival of patients with NUT carcinoma is incredibly unusual, especially in patients with tumors that exhibit a BRD4 rearrangement. False negative FISH is a pitfall in diagnosing NUT carcinoma; NUT immunostaining and RNA sequencing are more sensitive diagnostic methods.

Middle Ear and Temporal Bone Nonkeratinizing Squamous Cell Carcinomas With DEK-AFF2 Fusion: An Emerging Entity

Primary squamous cell carcinomas (SCCs) of the middle ear and temporal bone are rare and usually keratinizing by morphology. Nonkeratinizing, basaloid SCCs arising in this area are exceedingly rare, and, due to the anatomic proximity to the skull base, nasopharynx, and nasal sinuses, the differential diagnosis is broad. Most tumors with squamous differentiation arising in these subsites are either viral-induced (human papillomavirus/Epstein-Barr virus) or rarely may have specific molecular alterations (BRD4-NUT, EWSR1-FLI translocations). Occasional tumors are negative for these findings, and their pathogenesis is unknown. A recently discovered DEK-AFF2 fusion was clinically detected in a series of 2 cases known to the authors. This fusion has been previously reported in the literature in a patient with a base of skull tumor who was an exceptional responder to programmed cell death protein 1 inhibitor therapy. We examine here the histomorphologic and molecular findings of 2 additional cases of an emerging entity. Two male patients were identified. Each had a primary middle ear/temporal bone mass with locally advanced disease. The histology was reviewed, and immunohistochemistry was performed. RNA-based next-generation sequencing was performed for clinical detection of diagnostic or actionable fusions. Both patients had basaloid/nonkeratinizing tumors on biopsy. They were positive for markers of squamous differentiation (HMWK, CK5, and p40). By RNA sequencing, they demonstrated the presence of a DEK-AFF2 fusion and were negative for EWSR1 and NUT translocations. The DEK-AFF2 fusion may define a novel diagnostic category of middle ear and temporal bone nonkeratinizing/basaloid SCCs. This fusion also may represent a potential avenue for immunotherapy in these patients. Further studies are needed to fully explore whether this fusion defines a location-specific clinicopathologic entity.

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.

Emerging entities in NUTM1-rearranged neoplasms

Structural alterations of NUTM1 were originally thought to be restricted to poorly differentiated carcinomas with variable squamous differentiation originating in the midline organs of children and adolescents. Termed NUT carcinomas (NCs), they were defined by a t(15;19) chromosomal rearrangement that was found to result in a BRD4-NUTM1 gene fusion. However, the use of DNA and RNA-based next-generation sequencing has recently revealed a multitude of new NUTM1 fusion partners in a diverse array of neoplasms including sarcoma-like tumors, poromas, and acute lymphoblastic leukemias (ALLs) that we propose to call NUTM1-rearranged neoplasms (NRNs). Intriguingly, the nosology of NRNs often correlates with the functional classification of the fusion partner, suggesting different oncogenic mechanisms within each NRN division. Indeed, whereas NCs are characterized by their aggressiveness and intransigence to standard therapeutic measures, the more positive clinical outcomes seen in some sarcoma and ALL NRNs may reflect these mechanistic differences. Here we provide a broad overview of the molecular, nosological, and clinical features in these newly discovered neoplastic entities. We describe how aberrant expression of NUTM1 due to fusion with an N-terminal DNA/chromatin-binding protein can generate a potentially powerful chromatin modifier that can give rise to oncogenic transformation in numerous cellular contexts. We also conclude that classification, clinical behavior, and therapeutic options may be best defined by the NUTM1 fusion partner rather than by tumor morphology or immunohistochemical profile.

HDAC Overexpression in a NUT Midline Carcinoma of the Parotid Gland with Exceptional Survival: A Case Report

NUT midline carcinoma (NMC) is a recently described entity with a predilection for young individuals, characterised by a rearrangement of NUT, most commonly with BRD4. It usually involves midline structures, with a minority of cases presenting outside the midline axis. Given its dismal prognosis, new molecularly targeted therapies (eg, HDAC inhibitors) are gaining ground, but the HDAC expression pattern remains unknown. We describe the exceptional evolution of a NMC arising in the parotid gland. A 34-year-old male presented with a rapidly growing 35 mm left-parotid mass. Parotidectomy and lymphadenectomy were performed. The tumour invaded the surrounding soft tissue and lay adjacent to the surgical margin. No lymph node metastases were identified. Histology revealed blue nests of undifferentiated cells merging with foci of necrosis and occasional abrupt foci of keratinising squamous epithelium. FISH analysis confirmed a rearrangement of NUT, but not of BRD4. A diagnosis of NMC was rendered. Currently, after adjuvant chemoradiotherapy and 47 months after diagnosis, the patient is alive and well. The tumour was found to have increased immunoexpression of HDAC2, 4 and 6 and phospho-HDAC4/5/7. This case emphasises the importance of considering NMC in the differential diagnosis of poorly differentiated carcinomas of the head and neck region in young adults, even away from midline structures. As molecular targets hold the promise of successful therapy for the vast majority of NMC patients, the knowledge of their HDAC expression patterns will probably be relevant.