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Ju Y, Velazquez M, Sherrod A, Wang T. Diagnostic significance and cytological features of NUT carcinoma by EBUS-FNA, a case report and literature review. Cytopathology 2024; 35:497-502. [PMID: 38551146 DOI: 10.1111/cyt.13379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 06/11/2024]
Abstract
Cytomorphological features of NUT carcinoma include sheets or discrete nests of primitive, monotonous, round to oval shaped tumour cells with high N/C ratio and brisk mitotic figures. Abrupt squamous differentiation might be a diagnostic hint. More than 50% positivity of NUT immunohistochemistry staining is diagnostic. NUT carcinoma represents a poorly differentiated malignancy by extremely aggressive clinical course and poor prognosis. It frequently manifests in midline organs, notably in the mediastinum and lung. The rising preferences for utilizing the EBUS-FNA procedure in diagnosing thoracic and lung lesions stems from its high diagnostic yield. Hence, recognizing the cytomorphological features of NUT carcinoma is crucial for timely treatment and improved patient survival.
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Affiliation(s)
- Yaping Ju
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Los Angeles General Medical Center, Los Angeles, California, USA
| | - Miriam Velazquez
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Los Angeles General Medical Center, Los Angeles, California, USA
| | - Andy Sherrod
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Los Angeles General Medical Center, Los Angeles, California, USA
| | - Tiannan Wang
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Los Angeles General Medical Center, Los Angeles, California, USA
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2
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Viswanathan K, Hahn E, Dogan S, Weinreb I, Dickson BC, MacMillan C, Katabi N, Magliocca K, Ghossein R, Xu B. The histological spectrum and immunoprofile of head and neck NUT carcinoma: A multicentre series of 30 cases. Histopathology 2024. [PMID: 38708903 DOI: 10.1111/his.15204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 05/07/2024]
Abstract
BACKGROUND AND AIM Head and neck nuclear protein of testis carcinoma (HN-NUT) is a rare form of carcinoma diagnosed by NUT immunohistochemistry positivity and/or NUTM1 translocation. Although the prototype of HN-NUT is a primitive undifferentiated round cell tumour (URC) with immunopositivity for squamous markers, it is our observation that it may assume variant histology or immunoprofile. METHODS We conducted a detailed clinicopathological review of a large retrospective cohort of 30 HN-NUT, aiming to expand its histological and immunohistochemical spectrum. RESULTS The median age of patients with HN-NUT was 39 years (range = 17-86). It affected the sinonasal tract (43%), major salivary glands (20%), thyroid (13%), oral cavity (7%), larynx (7%), neck (7%) and nasopharynx (3%). Although most cases of HN-NUT (63%) contained a component of primitive URC tumour, 53% showed other histological features and 37% lacked a URC component altogether. Variant histological features included basaloid (33%), differentiated squamous/squamoid (37%), clear cell changes (13%), glandular differentiation (7%) and papillary architecture (10%), which could co-exist. While most HN-NUT were positive for keratins, p63 and p40, occasional cases (5-9%) were entirely negative. Immunopositivity for neuroendocrine markers and thyroid transcription factor-1 was observed in 33 and 36% of cases, respectively. The outcome of HN-NUT was dismal, with a 3-year disease specific survival of 38%. CONCLUSIONS HN-NUT can affect individuals across a wide age range and arise from various head and neck sites. It exhibits a diverse spectrum of histological features and may be positive for neuroendocrine markers, potentially leading to underdiagnosis. A low threshold to perform NUT-specific tests is necessary to accurately diagnose HN-NUT.
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Affiliation(s)
- Kartik Viswanathan
- Department of Pathology, Emory University Hospital Midtown, Atlanta, GA, USA
| | - Elan Hahn
- Department of Pathology and Laboratory Medicine, Sinai Health System, Toronto, ON, Canada
| | - Snjezana Dogan
- Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ilan Weinreb
- Department of Pathology, University Health Network, Toronto, ON, Canada
| | - Brendan C Dickson
- Department of Pathology and Laboratory Medicine, Sinai Health System, Toronto, ON, Canada
| | - Christina MacMillan
- Department of Pathology and Laboratory Medicine, Sinai Health System, Toronto, ON, Canada
| | - Nora Katabi
- Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Kelly Magliocca
- Department of Pathology, Emory University Hospital Midtown, Atlanta, GA, USA
| | - Ronald Ghossein
- Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Bin Xu
- Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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3
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Li CY, Salihoglu S, Civantos FJ, Velez Torres JM. Exploring cytologic features and potential diagnostic challenges of metastatic NUT carcinoma to the parotid gland: A case report and a comprehensive literature review. Diagn Cytopathol 2024. [PMID: 38655736 DOI: 10.1002/dc.25335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024]
Abstract
NUT carcinoma (NC) is a highly aggressive, poorly differentiated carcinoma that harbors a t(15:19) translocation, leading to the fusion of the NUTM1 gene. While the upper aerodigestive tract along the midline (head, neck, thorax, and mediastinum) is commonly reported as the primary site of NC, subsequent cases have emerged in diverse locations. Achieving a definitive diagnosis based solely on morphology is challenging; however, it can be achieved using immunohistochemistry (IHC) specific to the NUT antibody or by demonstrating the characteristic BRD4::NUTM1 fusion. Accurate and timely diagnosis can potentially inform patient management and guide treatment. While histologic documentation of NC is commonly found, there is a limited description of its cytologic features. A 39-year-old male with a history of sinonasal squamous cell carcinoma (SCC) presented with a right parotid mass aspirated via fine needle aspiration cytology (FNA). Histologic examination of the previous sinonasal pathology reviewed at our institution revealed sheets of primitive-appearing, monotonous, undifferentiated cells with distinct, prominent nucleoli. Additionally, there were foci of abrupt keratinization, accompanied by a notable neutrophilic infiltrate. The initial diagnosis of SCC was reclassified to NC and confirmed through NUT IHC and molecular testing. Although the parotid FNA initially suggested the possibility of a variety of small round blue cell tumors, it exhibited morphological similarities to the sinonasal tumor, leading to the diagnosis of metastatic NC. Cytomorphologic features of NC are limited and can overlap with various small round blue cell tumors. Correct classification is especially pivotal in the era of targeted therapy, considering the ongoing development and evaluation of BET inhibitors targeting BRD4.
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Affiliation(s)
- Crystal Y Li
- Department of Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Salih Salihoglu
- Department of Industrial and Systems Engineering, University of Miami College of Engineering, Miami, Florida, USA
| | - Francisco J Civantos
- Department of Otolaryngology - Head and Neck Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jaylou M Velez Torres
- Department of Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
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4
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Ninomiya H, Sato Y, Inamura K, Dobashi A, Takeuchi K, Mitani H, Mun M, Nishio M, Ishikawa Y. Neuroendocrine and squamous cell phenotypes of NUT carcinoma are potential diagnostic pitfalls that discriminating it from mimickers, such as small cell and squamous cell carcinoma. Diagn Pathol 2024; 19:27. [PMID: 38326851 PMCID: PMC10851512 DOI: 10.1186/s13000-024-01448-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/16/2024] [Indexed: 02/09/2024] Open
Abstract
INTRODUCTION NUT carcinoma is a rare cancer associated with a poor prognosis. Because of its rarity, its diagnosis is challenging and is usually made by excluding other diagnoses. Immunohistochemical analysis is a reliable technique that contributes to a correct diagnosis, but overestimating the expression of neuroendocrine (NE) markers may result in an incorrect diagnosis. In this study, we established the immunohistochemical phenotypes of NUT carcinoma compared with tumors that mimic its phenotype to identify potential diagnostic pitfalls. METHODS Eight cases of NUT carcinoma were examined along with eight basaloid squamous cell carcinomas and thirteen cases of small cell carcinoma using an immunohistochemical panel consisting of various antibodies. RESULTS Of the eight NUT carcinomas, three patients had a smoking history. All the cases examined for INSM1 were positive (6/6, 100%), although the staining was somewhat weak. Among the NE markers, synaptophysin was variably positive in two NUT carcinomas (2/6, 33%); however, all cases were negative for ASCL1, chromogranin A, and CD56. Moreover, the squamous cell markers, p40 and CK5/6, were weakly expressed in 4/6 (67%) and 3/6 (50%) of the NUT carcinomas, respectively. CONCLUSIONS For tumors with an ambiguous morphology, applying the neuroendocrine phenotype of NUT carcinoma may be misleading; particularly, when distinguishing it from small-cell carcinoma. Similarly, null or weak expression of squamous cell markers may be observed in NUT carcinoma, but this differs from squamous cell carcinoma, which consistently demonstrates strong positivity for squamous cell markers.
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Affiliation(s)
- Hironori Ninomiya
- Division of Pathology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.
- Department of Pathology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
| | - Yukiko Sato
- Division of Pathology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
- Department of Pathology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Kentaro Inamura
- Division of Pathology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
- Department of Pathology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Akito Dobashi
- Pathology Project for Molecular Targets, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Kengo Takeuchi
- Division of Pathology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
- Department of Pathology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
- Pathology Project for Molecular Targets, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Hiroki Mitani
- Division of Head and Neck Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Mingyon Mun
- Thoracic Surgical Oncology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Makoto Nishio
- Thoracic Medical Oncology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Yuichi Ishikawa
- Division of Pathology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
- Department of Pathology, Mita Hospital, International University of Health and Welfare, Tokyo, Japan
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5
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Noorwali H, Casiraghi O, Classe M, Adam J, Ngo C, Ghigna MR, Kanaan C, Khneisser P, Bani MA, Cotteret S, Scoazec JY. Immunodetection of NUT Protein: Implementation, Indications, and Results in a Tertiary Reference Center. Appl Immunohistochem Mol Morphol 2024; 32:64-70. [PMID: 37972936 DOI: 10.1097/pai.0000000000001172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 10/12/2023] [Indexed: 11/19/2023]
Abstract
The immunodetection of NUT protein is a reliable tool to identify NUT carcinoma, a rare and still underdiagnosed tumor entity. The technique was implemented in 2017 in our department, a tertiary reference center with a large recruitment in all tumor types, including head and neck and thoracic tumors. We evaluated its use over a 6-year period (2017-2022) to (a) describe the indications for the technique, (b) determine the number of NUT carcinomas detected and confirmed by Fluorescence in situ hybridization, and (c) describe briefly the characteristics of these tumors. Over the study period, 382 NUT immunodetections were performed; the annual number of requests varied from 45 to 83. All 21 pathologists of the department made at least one request (range: 1 to 94; annual mean: 18.2). 54.7% of immunodetections were performed for internal cases, 37% for cases submitted for consultation, and 8.3% for cases submitted for confirmation of a suspected diagnosis. The main indications were poorly differentiated tumors of the head and neck region (39%) and the thorax (19.6%), and difficult-to-classify soft tissue tumors (11.8%). Twelve cases of NUT carcinoma were detected by immunohistochemistry and confirmed by Fluorescence in situ hybridization. Seven were from the head and neck region (4.7% of the tumors tested), 4 from lung or mediastinum (5.3%), 1 from an unknown primary at the time of diagnosis. In conclusion, the implementation of NUT immunodetection in the daily workflow of a pathology department improves the detection of NUT carcinoma. This becomes essential with the emergence of potential targeted therapies.
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6
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Vocino Trucco G, Righi L, Volante M, Papotti M. Updates on lung neuroendocrine neoplasm classification. Histopathology 2024; 84:67-85. [PMID: 37794655 DOI: 10.1111/his.15058] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023]
Abstract
Lung neuroendocrine neoplasms (NENs) are a heterogeneous group of pulmonary neoplasms showing different morphological patterns and clinical and biological characteristics. The World Health Organisation (WHO) classification of lung NENs has been recently updated as part of the broader attempt to uniform the classification of NENs. This much-needed update has come at a time when insights from seminal molecular characterisation studies revolutionised our understanding of the biological and pathological architecture of lung NENs, paving the way for the development of novel diagnostic techniques, prognostic factors and therapeutic approaches. In this challenging and rapidly evolving landscape, the relevance of the 2021 WHO classification has been recently questioned, particularly in terms of its morphology-orientated approach and its prognostic implications. Here, we provide a state-of-the-art review on the contemporary understanding of pulmonary NEN morphology and the potential contribution of artificial intelligence, the advances in NEN molecular profiling with their impact on the classification system and, finally, the key current and upcoming prognostic factors.
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Affiliation(s)
| | - Luisella Righi
- Department of Oncology, University of Turin, Turin, Italy
| | - Marco Volante
- Department of Oncology, University of Turin, Turin, Italy
| | - Mauro Papotti
- Department of Oncology, University of Turin, Turin, Italy
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7
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Yoshida A. NUT carcinoma and thoracic SMARCA4-deficient undifferentiated tumour: facts and controversies. Histopathology 2024; 84:86-101. [PMID: 37873676 DOI: 10.1111/his.15063] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/09/2023] [Accepted: 09/24/2023] [Indexed: 10/25/2023]
Abstract
NUT carcinoma and thoracic SMARCA4-deficient undifferentiated tumour are unique entities in the 5th edition of the World Health Organisation (WHO) Classification of Thoracic Tumours, whose definitions include molecular genetic abnormalities. These aggressive tumours require rapid work-ups on biopsies, but a broad list of differential diagnoses poses challenges for practising pathologists. This review provides an update on their key clinicopathological and molecular characteristics, as well as controversies regarding tumour classification and diagnostic strategy. Phenotypical assessment plays a substantial role in diagnosis because recurrent and predictable clinicopathological findings exist, including robust immunohistochemical phenotypes. Accurate diagnosis is crucial for appropriate management and a clearer understanding of the disease.
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Affiliation(s)
- Akihiko Yoshida
- Department of Diagnostic Pathology, National Cancer Center Hospital, Tokyo, Japan
- Rare Cancer Center, National Cancer Center, Tokyo, Japan
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8
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Chen M, Chen X, Zhang Y, Wang W, Jiang L. Clinical and molecular features of pulmonary NUT carcinoma characterizes diverse responses to immunotherapy, with a pathologic complete response case. J Cancer Res Clin Oncol 2023:10.1007/s00432-023-04621-5. [PMID: 36752907 DOI: 10.1007/s00432-023-04621-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/27/2023] [Indexed: 02/09/2023]
Abstract
PURPOSE Nuclear protein in testis (NUT) carcinoma is an uncommon malignant cancer characterized by NUTM1 rearrangement. We aimed to investigate the clinicopathological and molecular features and immunotherapy of pulmonary NUT carcinoma. METHODS Immunohistochemistry (IHC) for NUT (C52B1) and programmed cell death ligand 1 (PD-L1: 22C3) and fluorescence in situ hybridization (FISH) for NUTM1 break and BRD4-NUTM1 fusion were performed on six pulmonary NUT carcinoma samples. RESULTS The 6 pulmonary NUT carcinoma samples were obtained from 5 males and 1 female, with ages ranging from 31 to 73 years (average, 46 years). Five tumors occurred in the lobes, with one in the trachea. Pathologically, all cases showed primitive-appearing round to epithelioid cells growing in nests and sheets. Squamous differentiation and abrupt keratinization were observed. All tumors expressed the NUT protein and p63, and 4 tumors showed focal synaptophysin, but PD-L1 expression was not observed. All cases displayed NUTM1 rearrangement, 5 had BRD4-NUTM1 fusion, and one had an unknown partner. Three patients presented regional lymph node involvement at diagnosis. Five patients underwent intensive radiation and/or chemotherapy. Furthermore, 2 patients (1 and 2) received a combination of PD-L1 inhibitor and chemotherapy. Patient 1 exhibited a poor response and soon showed tumor progression and metastasis; however, patient 2 responded remarkably and achieved pathologic complete response (pCR) without uncontrollable adverse events. The overall survival time was 2.9 months. CONCLUSIONS Pulmonary NUT carcinoma exhibits poorly differentiated morphological features with diffuse NUT staining, low PD-L1 expression, and NUTM1 rearrangement. Despite its poor prognosis, it presents a diverse response to immunotherapy. Immune checkpoint inhibitors (ICIs) need to be further explored in NUT carcinoma.
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Affiliation(s)
- Min Chen
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xiaohua Chen
- Department of Pathology, The Second People's Hospital of Yibin, Yibin, 644000, China
| | - Ying Zhang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Weiya Wang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Lili Jiang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China.
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Diagnosis, Treatment and Prognosis of Primary Pulmonary NUT Carcinoma: A Literature Review. Curr Oncol 2022; 29:6807-6815. [PMID: 36290813 PMCID: PMC9600367 DOI: 10.3390/curroncol29100536] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/13/2022] [Accepted: 09/19/2022] [Indexed: 01/13/2023] Open
Abstract
NUT carcinoma is a rare, highly lethal cancer characterized with the rearrangement of the nuclear protein in testis (NUT) gene on chromosome 15q14, which primarily occurs in the midline organs. Primary pulmonary NUT carcinoma (NC) lacks characteristic clinical manifestations, which leads to the high rate of misdiagnose and nonstandard treatment. To date, fewer than one hundred cases have been reported worldwide. Here, a comprehensive literature search involving a total of 35 articles with 55 patients was conducted in this paper. We reviewed and analyzed the associated clinical and pathological characteristics, the efficacy of various treatment options and the prognosis. Pulmonary NC mainly occurred in middle young-aged men (median age, 36) with no smoking history (2:1) and would present with symptoms of cough (63.6%), dyspnea (29.5%), chest pain (18.2%) and hemoptysis (18.2%). The initial imaging frequently revealed large and irregular lesions in the lower lobe (46.5%) of the left or right lungs; lymph node metastasis was also prevalent (91.9%). A focal squamous differentiation with abrupt keratinization often occurred in the undifferentiated or poorly differentiated (93.75%) tumor cells, with abundant necrosis and numerous neutrophils infiltrated. The mean overall survival (OS) in patients of this malignant disease was 6.21 months, and the median OS was 4.4 months. According to our results, this disease is sensitive to radiotherapy, and chemoradiotherapy (either concurrent chemoradiotherapy or sequential chemoradiotherapy) was the most efficient therapeutic regimen to prolong the OS of patients with pulmonary NC.
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10
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Georgantzoglou N, Aghighi M, Cote G, Hung YP, Kerr DA, Pettus J, Linos K. Primary Spindle Cell Sarcoma of the Lung with MGA::NUTM1 Fusion: An Extremely Rare Case of a Potentially Emerging Entity and Review of the Literature. Int J Surg Pathol 2022; 30:931-938. [PMID: 35388715 DOI: 10.1177/10668969221092125] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Originally described in a rare subset of poorly differentiated squamous cell carcinomas termed NUT carcinomas, NUTM1 rearrangements are now known to characterize a wide spectrum of neoplasms including sarcomas, poromas/porocarcinomas, unclassified adnexal carcinomas and pediatric acute lymphoblastic leukemia. The advent of next-generation sequencing (NGS) has led to the identification of a multitude of novel fusion partners in addition to BRD4, which was initially reported in the majority of NUT carcinomas. NUTM1-rearranged sarcomas usually harbor fusions with the MAD gene family (MXD1, MXD4, MGA) and present as spindle cell proliferations in diverse locations in patients of all ages. Herein, we present a very rare case of spindle cell sarcoma of the lung, which harbored a NUTM1::MGA fusion and offer a comprehensive update of the recent data.
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Affiliation(s)
- Natalia Georgantzoglou
- Department of Pathology and Laboratory Medicine, 22916Dartmouth Hitchcock Medical Center, Lebanon, NH, USA
| | - Maryam Aghighi
- Department of Pathology, 21640Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Gregory Cote
- Department of Hematology/Oncology, 2348Massachusetts General Hospital, Boston, MA, USA
| | - Yin P Hung
- Department of Pathology, 2348Massachusetts General Hospital, Boston, MA, USA
| | - Darcy A Kerr
- Department of Pathology and Laboratory Medicine, 22916Dartmouth Hitchcock Medical Center, Lebanon, NH, USA.,Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Jason Pettus
- Department of Pathology and Laboratory Medicine, 22916Dartmouth Hitchcock Medical Center, Lebanon, NH, USA.,Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Konstantinos Linos
- Department of Pathology and Laboratory Medicine, 22916Dartmouth Hitchcock Medical Center, Lebanon, NH, USA.,Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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11
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Chen M, Zhao S, Liang Z, Wang W, Zhou P, Jiang L. NUT carcinoma of the parotid gland: report of two cases, one with a rare ZNF532-NUTM1 fusion. Virchows Arch 2022; 480:887-897. [DOI: 10.1007/s00428-021-03253-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 12/20/2022]
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12
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Zhou J, Duan M, Jiao Q, Chen C, Xing A, Su P, Tang J, Zhang H, Liu Z. Primary Thyroid NUT Carcinoma With High PD-L1 Expression and Novel Massive IGKV Gene Fusions: A Case Report With Treatment Implications and Literature Review. Front Oncol 2022; 11:778296. [PMID: 35127482 PMCID: PMC8807656 DOI: 10.3389/fonc.2021.778296] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 12/23/2021] [Indexed: 12/17/2022] Open
Abstract
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.
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Affiliation(s)
- Juan Zhou
- Department of Pathology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Miao Duan
- Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Qiong Jiao
- Department of Pathology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Chunyan Chen
- Department of Pathology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Aiyan Xing
- Department of Pathology, Qilu Hospital of Shandong University, Jinan, China
| | - Peng Su
- Department of Pathology, Qilu Hospital of Shandong University, Jinan, China
| | - Juan Tang
- Department of Pathology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Hui Zhang
- Department of Pathology, Qilu Hospital of Shandong University, Jinan, China
- *Correspondence: Hui Zhang, ; Zhiyan Liu,
| | - Zhiyan Liu
- Department of Pathology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
- *Correspondence: Hui Zhang, ; Zhiyan Liu,
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13
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Kazdal D, Hofman V, Christopoulos P, Ilié M, Stenzinger A, Hofman P. Fusion-positive non-small cell lung carcinoma: Biological principles, clinical practice, and diagnostic implications. Genes Chromosomes Cancer 2022; 61:244-260. [PMID: 34997651 DOI: 10.1002/gcc.23022] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/26/2021] [Accepted: 12/27/2021] [Indexed: 12/11/2022] Open
Abstract
Based on superior efficacy and tolerability, targeted therapy is currently preferred over chemotherapy and/or immunotherapy for actionable gene fusions that occur in late-stage non-small cell lung carcinoma (NSCLC). Consequently, current clinical practice guidelines mandate testing for ALK, ROS1, NTRK, and RET gene fusions in all patients with newly diagnosed advanced non-squamous NSCLC (NS-NSCLC). Gene fusions can be detected using different approaches, but today RNA next-generation sequencing (NGS) or combined DNA/RNA NGS is the method of choice. The discovery of other gene fusions (involving, eg, NRG1, NUT, FGFR1, FGFR2, MET, BRAF, EGFR, SMARC fusions) and their partners has increased progressively in recent years, leading to the development of new and promising therapies and mandating the development and implementation of comprehensive detection methods. The purpose of this review is to focus on recent data concerning the main gene fusions identified in NSCLC, followed by the discussion of major challenges in this domain.
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Affiliation(s)
- Daniel Kazdal
- Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.,Translational Lung Research Center (TLRC) Heidelberg, Heidelberg, Germany.,German Center for Lung Research (DZL), Heidelberg, Germany
| | - Véronique Hofman
- Laboratory of Clinical and Experimental Pathology, Pasteur Hospital, Université Côte d'Azur, FHU OncoAge, Nice, France.,Centre Antoine Lacassagne Cancer Center, Université Côte d'Azur, CNRS, INSERM, IRCAN, FHU OncoAge, Nice, France.,Hospital-Integrated Biobank BB-0033-00025, Université Côte d'Azur, CHU Nice, FHU OncoAge, Nice, France
| | - Petros Christopoulos
- Translational Lung Research Center (TLRC) Heidelberg, Heidelberg, Germany.,German Center for Lung Research (DZL), Heidelberg, Germany.,Thoraxklinik and National Center for Tumor Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Marius Ilié
- Laboratory of Clinical and Experimental Pathology, Pasteur Hospital, Université Côte d'Azur, FHU OncoAge, Nice, France.,Centre Antoine Lacassagne Cancer Center, Université Côte d'Azur, CNRS, INSERM, IRCAN, FHU OncoAge, Nice, France.,Hospital-Integrated Biobank BB-0033-00025, Université Côte d'Azur, CHU Nice, FHU OncoAge, Nice, France
| | - Albrecht Stenzinger
- Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Lung Research (DZL), Heidelberg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Paul Hofman
- Laboratory of Clinical and Experimental Pathology, Pasteur Hospital, Université Côte d'Azur, FHU OncoAge, Nice, France.,Centre Antoine Lacassagne Cancer Center, Université Côte d'Azur, CNRS, INSERM, IRCAN, FHU OncoAge, Nice, France.,Hospital-Integrated Biobank BB-0033-00025, Université Côte d'Azur, CHU Nice, FHU OncoAge, Nice, France
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14
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Rekhtman N. Lung neuroendocrine neoplasms: recent progress and persistent challenges. Mod Pathol 2022; 35:36-50. [PMID: 34663914 PMCID: PMC8695375 DOI: 10.1038/s41379-021-00943-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/28/2021] [Accepted: 09/28/2021] [Indexed: 02/07/2023]
Abstract
This review summarizes key recent developments relevant to the pathologic diagnosis of lung neuroendocrine neoplasms, including carcinoids, small cell lung carcinoma (SCLC), and large cell neuroendocrine carcinoma (LCNEC). Covered are recent insights into the biological subtypes within each main tumor type, progress in pathological diagnosis and immunohistochemical markers, and persistent challenging areas. Highlighted topics include highly proliferative carcinoids and their distinction from small cell and large cell neuroendocrine carcinomas (NECs), the evolving role of Ki67, the update on the differential diagnosis of NEC to include thoracic SMARCA4-deficient undifferentiated tumors, the recent data on SCLC transcriptional subtypes with the emergence of POU2F3 as a novel marker for the diagnosis of SCLC with low/negative expression of standard neuroendocrine markers, and the update on the diagnosis of LCNEC, particularly in biopsies. There has been remarkable recent progress in the understanding of the genetic and expression-based profiles within each type of lung neuroendocrine neoplasm, and it is hoped that these insights will enable the development of novel diagnostic, prognostic, and predictive biomarkers to aid in the pathologic assessment of these tumors in the future.
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Affiliation(s)
- Natasha Rekhtman
- Department of Pathology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY, 10065, USA.
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15
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Unusual lung tumors-from morphology to genetics. Mod Pathol 2022; 35:57-65. [PMID: 34518633 DOI: 10.1038/s41379-021-00914-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 11/08/2022]
Abstract
Most pathologists are well versed in the diagnosis of lung cancer, given the common nature of the disease. Occasionally more unusual neoplasms are encountered in lung biopsies and resections, which may be difficult to distinguish from "run of the mill" lung cancer cases based on overlapping morphologic and immunophenotypic features. The accurate diagnosis of these rare entities is quite challenging and requires careful morphological examination paired with judicious use of ancillary immunohistochemical and genetic studies. Herein, the clinicopathological and genetic features of five unusual lung tumors will be reviewed, including thoracic SMARCA4-deficient undifferentiated tumor, NUT carcinoma, sclerosing pneumocytoma, primary pulmonary myxoid sarcoma/angiomatoid fibrous histiocytoma, and bronchiolar adenoma/ ciliated muconodular papillary tumor. Since recognition of these entities by pathologists is of increasing importance to guide prognosis and therapy, emphasis will be placed on practical tips to reach these rare diagnoses with confidence.
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16
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NUTM1-Rearranged Neoplasms-A Heterogeneous Group of Primitive Tumors with Expanding Spectrum of Histology and Molecular Alterations-An Updated Review. Curr Oncol 2021; 28:4485-4503. [PMID: 34898574 PMCID: PMC8628659 DOI: 10.3390/curroncol28060381] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/03/2021] [Accepted: 11/05/2021] [Indexed: 12/13/2022] Open
Abstract
Nuclear protein of testis (NUT), a protein product of the NUTM1 gene (located on the long arm of chromosome 15) with highly restricted physiologic expression in post-meiotic spermatids, is the oncogenic driver of a group of emerging neoplasms when fused with genes involved in transcription regulation. Although initially identified in a group of lethal midline carcinomas in which NUT forms fusion proteins with bromodomain proteins, NUTM1-rearrangement has since been identified in tumors at non-midline locations, with non-bromodomain partners and with varied morphology. The histologic features of these tumors have also expanded to include sarcoma, skin adnexal tumors, and hematologic malignancies that harbor various fusion partners and are associated with markedly different clinical courses varying from benign to malignant. Most of these tumors have nondescript primitive morphology and therefore should be routinely considered in any undifferentiated neoplasm. The diagnosis is facilitated by the immunohistochemical use of the monoclonal C52 antibody, fluorescence in situ hybridization (FISH), and, recently, RNA-sequencing. The pathogenesis is believed to be altered expression of oncogenes or tumor suppressor genes by NUT-mediated genome-wide histone modification. NUTM1-rearranged neoplasms respond poorly to classical chemotherapy and radiation therapy. Targeted therapies such as bromodomain and extraterminal domain inhibitor (BETi) therapy are being developed. This current review provides an update on NUTM1-rearranged neoplasms, focusing on the correlation between basic sciences and clinical aspects.
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17
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Gasljevic G, Matter MS, Blatnik O, Unk M, Dirnhofer S. NUT Carcinoma: A Clinical, Morphological and Immunohistochemical Mimicker-The Role of RNA Sequencing in the Diagnostic Procedure. Int J Surg Pathol 2021; 30:273-277. [PMID: 34738485 PMCID: PMC9003774 DOI: 10.1177/10668969211047981] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Background: NUT carcinoma is a highly aggressive and rare subset of squamous cell carcinoma with grim prognosis. It is under-recognized by both pathologists and oncologists. Recognition is challenging due to its rareness and the fact that its clinical and laboratory features as well as morphological and immunohistochemical characteristics may mimic other malignancies. Case presentation: An interesting case of NUT carcinoma in a 47-year-old male with a large tumor mass in the inferior part of the mediastinum and left lung and increased levels of serum alpha fetoprotein (AFP) is described. Immunohistochemical analysis of both the primary tumor in a bronchoscopy specimen and an excisional biopsy of a subcutaneous metastasis showed positivity for AFP and leukocyte common antigen (LCA) that were misleading and resulted in diagnostic pitfalls of mediastinal germ cell tumor (clinically) and hematolymphoid neoplasm (pathologic report). Immunohistochemical demonstration of NUT protein expression revealed the proper diagnosis, which was further confirmed by RNA sequencing revealing a BRD4-NUTM1 gene fusion.Conclusions: Since NUT carcinoma can show a wide spectrum of histological and immunophenotypic features and can clinically mimic other tumors, use of RNA sequencing with identification of specific NUTM1 fusion partner could be crucial when there are discrepant clinical and histopathological findings. As well, since the category of so-called NUTM1-rearranged neoplasms is rapidly expanding, identification of NUTM1 fusion partner may be essential for the appropriate clinical management.
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Affiliation(s)
- Gorana Gasljevic
- 68196Department of Pathology, Zaloska 2, Ljubljana 1000, Slovenia
| | - Matthias S Matter
- 30262University Hospital Basel, University of Basel, Basel, Switzerland
| | - Olga Blatnik
- 68196Department of Pathology, Zaloska 2, Ljubljana 1000, Slovenia
| | - Mojca Unk
- Department of Medical Oncology, Zaloska 2, Ljubljana 1000, Slovenia
| | - Stefan Dirnhofer
- 30262University Hospital Basel, University of Basel, Basel, Switzerland
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18
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Li X, Shi H, Zhang W, Bai C, He M, Ta N, Huang H, Ning Y, Fang C, Qin H, Dong Y. Immunotherapy and Targeting the Tumor Microenvironment: Current Place and New Insights in Primary Pulmonary NUT Carcinoma. Front Oncol 2021; 11:690115. [PMID: 34660264 PMCID: PMC8515126 DOI: 10.3389/fonc.2021.690115] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
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.
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Affiliation(s)
- Xiang Li
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Hui Shi
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Wei Zhang
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Chong Bai
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Miaoxia He
- Department of Pathology, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Na Ta
- Department of Pathology, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Haidong Huang
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Yunye Ning
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Chen Fang
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Hao Qin
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
| | - Yuchao Dong
- Department of Respiratory and Critical Care Medicine, Changhai Hospital (The First Affiliated Hospital of Naval Medical University), Naval Medical University (Second Military Medical University), Shanghai, China
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19
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What Is New in Biomarker Testing at Diagnosis of Advanced Non-Squamous Non-Small Cell Lung Carcinoma? Implications for Cytology and Liquid Biopsy. JOURNAL OF MOLECULAR PATHOLOGY 2021. [DOI: 10.3390/jmp2020015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The discovery and clinical validation of biomarkers predictive of the response of non-squamous non-small-cell lung carcinomas (NS-NSCLC) to therapeutic strategies continue to provide new data. The evaluation of novel treatments is based on molecular analyses aimed at determining their efficacy. These tests are increasing in number, but the tissue specimens are smaller and smaller and/or can have few tumor cells. Indeed, in addition to tissue samples, complementary cytological and/or blood samples can also give access to these biomarkers. To date, it is recommended and necessary to look for the status of five genomic molecular biomarkers (EGFR, ALK, ROS1, BRAFV600, NTRK) and of a protein biomarker (PD-L1). However, the short- and more or less long-term emergence of new targeted treatments of genomic alterations on RET and MET, but also on others’ genomic alteration, notably on KRAS, HER2, NRG1, SMARCA4, and NUT, have made cellular and blood samples essential for molecular testing. The aim of this review is to present the interest in using cytological and/or liquid biopsies as complementary biological material, or as an alternative to tissue specimens, for detection at diagnosis of new predictive biomarkers of NS-NSCLC.
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20
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Chatzopoulos K, Boland JM. Update on genetically defined lung neoplasms: NUT carcinoma and thoracic SMARCA4-deficient undifferentiated tumors. Virchows Arch 2021; 478:21-30. [PMID: 33409598 DOI: 10.1007/s00428-020-03011-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/07/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022]
Abstract
NUT carcinoma, also known as NUT midline carcinoma, is an aggressive malignancy mainly affecting the midline structures of younger patients and almost invariably leading to death within a few months of the diagnosis. Morphologically, NUT carcinoma consists of sheets of monomorphous small or medium size cells with scant cytoplasm, commonly featuring areas of abrupt squamous differentiation with keratinization. Immunohistochemistry for NUT protein is sensitive and specific, typically showing a speckled nuclear reactivity, assisting in diagnosis. The molecular background of NUT carcinoma includes the reciprocal translocation t(15;19) leading to expression of the BRD4-NUT fusion transcript with oncogenic properties. Other less common genes may occasionally be fused with NUT not only in NUT carcinoma but also in other soft tissue tumors, highlighting the fact that NUT-rearranged tumors may represent a larger and more diverse family of neoplasms. Thoracic SMARCA4-deficient undifferentiated tumors are aggressive malignancies diagnosed more often in young male smokers, which often lead to death within a few months. SMARCA4-deficient tumors show undifferentiated morphology with occasional hepatoid and rhabdoid features. Immunohistochemically, the hallmark of diagnosis is loss of expression of SMARCA4 (BRG1). Concurrent loss of SMARCA2 expression, as well as expression of one or more stem cell markers SOX2, CD34, or SALL4 is common. Truncating mutations in SMARCA4, a catalytic subunit of the mammalian BAF (SWI/SNF) complex, are the dominant oncogenic molecular event underlying the pathogenesis of these tumors. SMARCA4 deficiency can also be seen as a passenger somatic event in multiple solid neoplasms manifesting as focal dedifferentiation and rhabdoid morphology.
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Affiliation(s)
- Kyriakos Chatzopoulos
- Division of Anatomic Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Jennifer M Boland
- Division of Anatomic Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
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