Nuclear protein in testis midline carcinomas: a lethal and underrecognized entity

Therapeutic approaches to sinonasal NUT carcinoma: a systematic review

PURPOSE

Sinonasal nuclear protein in testis carcinoma (SNUTC) is a rare, aggressive malignancy caused by genetic rearrangements in the NUTM1 gene. The prognosis of SNUTC ranks among the most unfavorable within the naso-sinusal district, with an overall survival of 9.7 months. This systematic review aimed to determine the best therapeutic strategy for SNUTC.

METHODS

We reviewed eligible articles for patient demographics, TNM and stage at presentation, best response after primary treatment, disease-free survival and overall survival (OS) times, other following therapy lines, and final outcomes.

RESULTS

Among 472 unique citations, 17 studies were considered eligible, with reported treatment data for 25 patients. Most studies (n = 12) were case reports. The most frequently administered treatment regimen was surgery as primary treatment and combined radiochemotherapy as second-line or adjuvant treatment. Four patients were alive at follow-up.

CONCLUSION

Basing on the existing literature, a standardized line in the treatment of SNUTC is not yet well delineated. A self-personalized strategy of therapy should be drawn on each patient affected by SNUTC.

Immunodetection of NUT Protein: Implementation, Indications, and Results in a Tertiary Reference Center

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.

Clinicopathological molecular characterizations of sinonasal NUT carcinoma: a report of two cases and a literature review

Background

Nuclear protein in testis (NUT) carcinoma (NC) is a rare, aggressive tumor with a typical NUTM1 gene rearrangement.

Methods

Herein, we report a series of 2 cases of sinonasal NC: one in a 16-year-old woman and one in a 37-year-old man. Immunohistochemistry (IHC) staining for NUT (C52B1), fluorescence in situ hybridization (FISH), and next generation sequencing (NGS) sequencing were performed to investigate the morphological and genetic features of sinonasal NC.

Results

The two cases presented similar pathological features and IHC markers, and typical morphological changes, including undifferentiated cells and abrupt keratinization, were observed, with numerous mitotic figures and widespread tumor necrosis. Diffuse expression of NUT, CK, p63, and p40 was noted, while the tumors were negative for synaptophysin, chromogranin A, S-100, EBV-ISH, and PD-L1. Both tumors harbored a NUTM1 rearrangement. Subsequent sequencing revealed a rare BRD3::NUTM1 fusion and a classic BRD4::NUTM1 fusion. In addition, MCL1 copy number gain (2.1), low tumor mutation burden and stable microsatellites, were also confirmed. Case 1 received surgery and chemoradiotherapy but died 13 months after local recurrence and subsequent lung and bone metastasis. Case 2 underwent chemoradiotherapy and unfortunately died from the disease 6 months later. A review of all previously reported cases of sinonasal NCs (n=55) revealed that these tumors occur more frequently in female pediatric patients (n=11, male: female =3:8), whereas this sex difference is not observed in adult patients (n=44, male: female =23:21). The median survival times of pediatric and adult patients were 17 and 13.8 months, respectively.

Conclusion

Sinonasal NC presents typical undifferentiated or poorly differentiated cells, abrupt keratinization features and heterogeneous genotypes, including BRD4::NUTM1 and BRD3::NUTM1 fusions, with low tumor mutation burden and stable microsatellites.

Sinonasal NUT carcinoma: A retrospective case series from a single institution

Purpose

Nuclear protein in testis (NUT) carcinoma is a rare, aggressive tumor defined by the presence of NUT gene rearrangement. The aim of this study was to describe the clinical, radiologic, and biological features of sinonasal NUT carcinoma.

Methods

We retrospectively investigated NUT expression with clinicopathologic features in 145 cases with sinonasal malignancies diagnosed from January 2017 to December 2021 and reviewed the reported cases.

Results

Three (3/145, 2.07%) cases showed strong nuclear expression for NUT immunohistochemical, including one male and two females with ages from 37 to 57 years (mean, 45.33 years). All three cases involved the nasal cavity and sinuses; one of them involved the orbit and intracranial area. Histologically, all subjects showed poorly differentiated, small round cell morphology with distinct nuclei. All patients received surgery and chemoradiotherapy. One patient died of the disease 13 months after diagnosis, and two survived 12 and 15 months, respectively, without evidence of tumor recurrence. 51 cases of sinonasal NUT carcinoma (mean age 40.96 years) have been described to date. Among them, 28 are male, and 23 are female. Most cases expressed p63, AE1/AE3, as well as p40.

Conclusion

NUT carcinoma is a rare and aggressive disease with a poor prognosis. It is crucial to perform NUT rearrangement-related tests for differential diagnosis of poorly differentiated/undifferentiated tumors in the nasal cavity and sinuses.

Case report: NUT carcinoma with MXI1::NUTM1 fusion characterized by abdominopelvic lesions and ovarian masses in a middle-aged female

Background

Nuclear protein of the testis (NUT) carcinoma is a rare subset of poorly differentiated, highly aggressive malignancy defined by NUTM1 gene rearrangements. Only three NUT cases of probable ovarian origin have been reported.

Case presentation

We report a case of NUT carcinoma in a 53-year-old female who presented with extensive abdominopelvic lesions and bilateral ovarian masses suggestive of advanced ovarian cancer. This patient was admitted to our hospital due to abdominal pain and distension for over two months. Imaging examinations suggested a possible malignancy of bilateral adnexal origin. This patient first underwent diagnostic laparoscopy. After receiving neoadjuvant chemotherapy, she underwent cytoreductive surgery. Surgical pathology showed infiltration of monotonous round tumor cells with no apparent differentiation characteristics. Immunohistochemistry (IHC) revealed nuclear expression of the NUT protein. And MXI1::NUTM1 fusion was identified by next-generation sequencing (NGS). Herein, we introduce an unusual NUT carcinoma and describe the clinical, imaging, and pathological features. In addition, we briefly reviewed the published literature and discussed the possibility of primary gynecological NUT carcinoma.

Conclusions

Identifying a NUT carcinoma arising from the abdominopelvic cavity is essential, and we underscore the need for NUT testing in undifferentiated malignant neoplasms that appear in this clinical setting. Although it is unclear from which origin this tumor arose, proper classification is essential for treatment planning.

Vimentin-positive and Alpha-fetoprotein-elevated Nuclear Protein of the Testis Midline Carcinoma: A Case Report and Review of the Literature

Nuclear protein of the testis (NUT) midline carcinoma (NMC) is a rare malignant tumor expressing NUT with BRD4/3 rearrangements and is sometimes misdiagnosed as germinoma, especially in alpha-fetoprotein (AFP)-elevated cases. A 28-year-old man had a mediastinal tumor with multiple bone metastases and elevated AFP levels. Imaging/laboratory findings led to a pathological diagnosis of extragonadal germinoma. After unsuccessful treatment with etoposide-cisplatin, he was re-diagnosed with sarcoma due to vimentin-positive findings. He was treated with adriamycin-ifosfamide, which resulted in disease-control. A posthumous examination clarified the NUT rearrangement. Even in cases with characteristic findings, such as elevated AFP levels and vimentin positivity, NMC should be considered as a differential diagnosis. We note, however, that adriamycin-ifosfamide has some efficacy in such cases.

Clinicopathological characteristics of primary lung nuclear protein in testis carcinoma: A single-institute experience of 10 cases

BACKGROUND

Nuclear protein in testis (NUT) carcinoma is a rare tumor associated with NUT rearrangement that can present as poorly differentiated to undifferentiated carcinoma, with or without abrupt squamous differentiation. It is often misdiagnosed as poorly differentiated carcinoma or undifferentiated carcinoma if NUT is not suspected. In this study, we retrospectively analyzed pulmonary NUT carcinoma cases diagnosed with NUT immunohistochemical staining and discuss the differential diagnosis to provide information for this rare and aggressive entity.

METHODS

Cases, diagnosed as "NUT carcinoma" in lung pleura and "metastatic NUT carcinoma from the lung" in lymph nodes were diagnosed between 2017 and 2019 at the Samsung Medical Center (SMC). Clinical features such as age, sex, treatment and follow-up period, and pathological reports were obtained by reviewing patients' electronic medical records.

RESULTS

A total of 10 NUT carcinoma cases were found in the SMC pathology database. Seven patients were men and six were non-smokers. Tumor cells showed various cellular features such as round, squamoid, and spindle. Some cases had initially been misdiagnosed as spindle cell neoplasm, round cell sarcoma, squamous cell carcinoma and small cell carcinoma. All cases showed diffuse strong nuclear expression of NUT immunohistochemical staining, and some were positive for p63 staining and negative for CD56 staining.

CONCLUSIONS

NUT carcinoma is often misdiagnosed because of its various morphologies. It is important to consider NUT as one of the differential diagnoses when encountering lung biopsy with undifferentiated morphology.

KEY POINTS

Due to various morphological features, NUT carcinoma can be misdiagnosed It is important to consider NUT carcinoma when diagnosing a poorly differentiated or undifferentiated tumor.

A 47-year-old woman with nuclear protein in testis midline carcinoma masquerading as a sinus infection: a case report and review of the literature

BACKGROUND

Nuclear protein in testis midline carcinoma is a rare, highly metastatic undifferentiated carcinoma that typically arises in midline structures and is characterized by having a fusion involving the nuclear protein in testis, NUT, gene. Nuclear protein in testis midline carcinoma has been identified in patients of all ages and is often initially misdiagnosed due to the rapid timeline of symptom onset.

CASE PRESENTATION

Here we report the case of a 47-year-old Caucasian woman with a nuclear protein in testis midline carcinoma that was initially mistaken for a sinus infection. After symptom progression while on an aggressive antibiotic regimen, the source of her symptoms was correctly identified as a sella mass. Comprehensive analysis of the tumor was performed, and standard cytogenetic analysis identified a translocation of 15q and 19p. Further testing identified a NUT-BRD4 fusion and confirmed the diagnosis of nuclear protein in testis midline carcinoma. Despite definitive diagnosis and surgical, radiation, and, ultimately, systemic therapy, she progressed rapidly, developing widespread metastases, and ultimately died from the disease 5 months after diagnosis.

CONCLUSIONS

Based on this and other previous reports, aggressive therapy should be initiated once nuclear protein in testis midline carcinoma is diagnosed and close surveillance employed in an attempt to prevent and/or recognize metastases as early as possible. Aggressive therapy has shown little efficacy such that the average overall survival for patients with nuclear protein in testis midline carcinoma is very short, often less than 6 months. Thus, early enrollment into clinical trials testing novel therapies for the treatment of nuclear protein in testis midline carcinoma should be considered. Finally, additional reports of nuclear protein in testis midline carcinoma are needed to fully characterize this rare and highly aggressive cancer.

Cytopathologic features of NUT midline carcinoma: A series of 26 specimens from 13 patients

BACKGROUND

NUT midline carcinoma (NMC) is an increasingly recognized neoplasm defined by rearrangements of the nuclear protein in testis (NUT) gene (also known as NUTM1). NMC is important to diagnose for prognostic and diagnostic reasons, but to date, only a small case series and rare case reports of the cytopathologic features of NMC have been published.

METHODS

All NMC specimens (confirmed by molecular testing and/or NUT immunoreactivity) with cytopathologic material available were identified at 2 academic centers. All smears were reviewed, and the cytologic characteristics were described.

RESULTS

Twenty-six cytopathologic specimens of NMC were identified from 13 patients: 8 men and 5 women ranging in age from 16 to 68 years (mean, 35 years). The NMCs arose in the mediastinum (n = 4), sinonasal tract (n = 4), neck (n = 2), lung (n = 1), lung and mediastinum (n = 1), and kidney (n = 1). Cytologic specimens included serous cavity effusions (n = 13), fine-needle aspirates (n = 9), bronchial brushings (n = 2), bronchial lavage (n = 1), and bronchial washings (n = 1). Ancillary studies were performed on cell blocks for only 6 samples from 4 patients: immunohistochemistry (n = 6) and flow cytometry (n = 1). All 13 NMCs had corresponding surgical pathology material. The NUT rearrangement status was known in 10 cases, and in 3 cases, the diagnosis was established by immunoreactivity for NUT. On cytologic smears, the NMCs were mostly hypercellular with monotonous, small to midsize, primitive-appearing cells largely distributed singly in a discohesive pattern. The tumor cells had round to oval nuclei that appeared mostly naked and devoid of cytoplasm. The nuclei varied in chromatin density from mostly pale, open chromatin to a hyperchromatic, neuroendocrine-type appearance, often with focal cell-to-cell molding, and most examples had a distinct, small nucleolus.

CONCLUSIONS

NMC is a recently recognized tumor that should be considered in the differential diagnosis of small round cell tumors, especially but not exclusively in the mediastinum and the head and neck. The cytologic features of NMC overlap considerably with those of other neoplasms, and a definitive diagnosis depends on a demonstration of NUT translocation by either immunohistochemical or molecular means. Cancer Cytopathol 2016;124:901-908. © 2016 American Cancer Society.

Small-Molecule Targeting of BET Proteins in Cancer

BET proteins have recently become recognized for their role in a broad range of cancers and are defined by the presence of two acetyl-histone reading bromodomains and an ET domain. This family of proteins includes BRD2, BRD3, BRD4, and BRDT. BRD4 is the most-studied BET protein in cancer, and normally serves as an epigenetic reader that links active chromatin marks to transcriptional elongation through activation of RNA polymerase II. The role of BRD3 and BRD4 first became known in cancer as mutant oncoproteins fused to the p300-recruiting NUT protein in a rare aggressive subtype of squamous cell cancer known as NUT midline carcinoma (NMC). BET inhibitors are acetyl-histone mimetics that specifically bind BET bromodomains, competitively inhibiting its engagement with chromatin. The antineoplastic effects of BET inhibitors were first demonstrated in NMC and have since been shown to be effective at inhibiting the growth of many different cancers, particularly acute leukemia. BET inhibitors have also been instrumental as tool compounds that have demonstrated the key role of BRD4 in driving NMC and non-NMC cancer growth. Many clinical trials enrolling patients with hematologic and solid tumors are ongoing, with encouraging preliminary findings. BET proteins BRD2, BRD3, and BRD4 are expressed in nearly all cells of the body, so there are concerns of toxicity with BET inhibitors, as well as the development of resistance. Toxicity and resistance may be overcome by combining BET inhibitors with other targeted inhibitors, or through the use of novel BET inhibitor derivatives.

NUT protein immunoreactivity in ovarian germ cell tumours

The aim of this study was to investigate NUT (nuclear protein in the testis) expression in ovarian germ cell tumours (GCTs). Immunostaining for NUT protein was performed in 10 mature cystic teratomas and in 49 malignant ovarian GCTs including 15 pure dysgerminomas, six dysgerminomas associated with gonadoblastoma, nine yolk sac tumours, 12 immature teratomas, and seven mixed malignant tumours. Only nuclear staining was considered a positive finding although cytoplasmic staining was noted when present. Thirty-seven (76%) malignant GCTs were NUT positive but staining was usually of weak to moderate intensity and observed in a relatively small proportion of neoplastic cells. Staining in immature teratomas and yolk sac tumours was restricted to foci of hepatoid and intestinal/glandular differentiation, where both nuclear and cytoplasmic reactivity were observed. In dysgerminoma associated with gonadoblastoma only the in situ and invasive germ cell elements were NUT positive. Nuclear staining was not seen in benign teratomas. Most malignant ovarian GCTs express NUT protein, albeit focally, and this should be considered when evaluating immunostaining in the differential diagnosis of poorly differentiated malignancies, particularly NUT midline carcinoma. Since NUT protein appears to play a role in normal germ cell maturation it may influence intestinal or hepatoid differentiation within malignant GCTs.

Cytological Features of a Variant NUT Midline Carcinoma of the Lung Harboring the NSD3-NUT Fusion Gene: A Case Report and Literature Review

Background. Nuclear protein in testis (NUT) midline carcinoma (NMC) is a very rare and aggressive malignancy. In more than two-thirds of these NMC cases, a fusion between NUT and BRD4 or BRD3 has been documented; other variants are rare. The cytology of NMC itself has been sparsely documented and that of variant NMC has never been reported. Case Presentation. A 36-year-old woman was admitted because of a rapidly progressing lung tumor with metastases to the breast and bone. We recently reported this patient as the first case of a variant NMC of the lung harboring an NSD3-NUT fusion, based on immunohistochemical and genetic analyses. Cytological material was available for the present review. A highly cellular smear contained a predominantly noncohesive pattern of monomorphic cells with diameters 2–2.5 times greater than those of small lymphocytes, with a round-to-oval nucleus, slightly irregular nuclear contours, variably prominent nucleoli, scant cytoplasm, and identifiable mitotic figures. Foci of stratification and overt pearl formation, including a dyskeratocyte, were occasionally observed. The necrotic background contained naked nuclei, karyorrhectic debris, apoptotic cells, and macrophages phagocytizing karyorrhectic debris; nuclear crushing was noted. Conclusion. The cytological features of a variant NMC of the lung are described for the first time.

Squamous cell carcinoma variants of the upper aerodigestive tract: a comprehensive review with a focus on genetic alterations

CONTEXT

Squamous cell carcinoma of the upper aerodigestive tract is a heterogenous entity. Although conventional squamous cell carcinomas are easily recognized, the morphologic variants of squamous cell carcinoma can present a diagnostic challenge. Familiarity with these variants is necessary because many are associated with unique risk factors and are characterized by specific molecular alterations (eg, nuclear protein in testis midline carcinomas). Perhaps the most important distinction is in identifying viral-related from nonviral-related carcinomas. The accurate diagnosis of these variants is necessary for prognostic and therapeutic reasons.

OBJECTIVES

To provide a clinicopathologic overview and summary of the molecular alterations of the common squamous cell carcinoma variants, including verrucous, spindle cell, acantholytic, adenosquamous, basaloid, and papillary squamous cell carcinoma, as well as nuclear protein in testis midline carcinoma, and to discuss the distinguishing features of human papillomavirus- and Epstein-Barr virus-related squamous cell carcinomas.

DATA SOURCES

Published peer-reviewed literature.

CONCLUSIONS

Familiarity with squamous cell carcinoma variants is essential for proper diagnosis and to guide appropriate clinical management. Further insight into the molecular alterations underlying those variants may lead to alterations in existing treatment approaches and to evolution of novel treatment modalities.

A rare Japanese case with a NUT midline carcinoma in the nasal cavity: a case report with immunohistochemical and genetic analyses

BACKGROUND

NUT (nuclear protein in testis) midline carcinoma (NMC) is a recently described aggressive malignancy that is genetically defined by rearrangements of the NUT locus at 15q14. In approximately two-thirds of cases, the characteristic t(15;19) results in the fusion oncogene BRD4-NUT. Only 10 sinonasal NMCs have been documented, none of which were Japanese cases.

CASE PRESENTATION

An 18-year-old woman was admitted because of a rapidly progressing tumor in the nasal cavity. A biopsy revealed an undifferentiated neoplasm without squamous differentiation. The tumor cells had round to oval nuclei with vesicular chromatin, prominent nucleoli, and scant cytoplasm. Immunohistochemical staining demonstrated a strong positivity for vimentin and NUT, with focal CD138 and only spotty EMA and cytokeratin AE1/AE3 staining. Cytogenetic and fluorescence in situ hybridization analyses revealed a t(15;19) and BRD4-NUT gene rearrangement. Direct sequencing identified the in-frame fusion of exon11 of BRD4 with exon2 of NUT. The patient was transferred to another hospital for chemoradiotherapy.

CONCLUSION

We herein describe the first Japanese case with an NMC of the sinonasal cavity, providing detailed and unambiguous cyto- and molecular genetic information on BRD4-NUT-rearrangement. The accumulation of cases with well-documented genetic data should provide clues to the treatment of this tumor entity.

The small round blue cell tumors of the sinonasal area: histological and immunohistochemical findings

Background

Primary Small round blue cell tumors (SRBCT) in sinonasal comprise histogenetically diverse entities with overlapping morphologic features. Because of the limited initial biopsy tissue materials, differential diagnostic difficulties may arise, and as they have different management, exact diagnosis and classification are very important.

Objectives

In this study, we analyzed the immunohistochemical expression of a panel of markers in the classification and diagnosis of sinonasal SRBCTs.

Material and Methods

This cross sectional study was performed on 36 paraffin embedded tissue samples. Histologic and immunohistochemical slides from 36 patients with SRBCT were analyzed retrospectively. The patients were admitted in Khalili hospital, Shiraz from 1383 to 1388.

Results

There were 13 women and 23 men with the mean age of 53 ±12.1. There were 9 malignant melanoma, seven poorly differentiated SCC; six lymphoma (DLBL); 4 SCNEC; three SNUC; two ON; two Ewing/PNET; two embryonal rhabdomyosarcoma, and one plasmacytoma. Pan-cytokeratin was strongly expressed poorly differentiated SCC and all cases of SNUC. Coexpression of desmin and nuclear myoD1 was only detected in rhabdomyosarcoma. HMB45 was only expressed in sinonasal melanoma. CD99 expression was identified only in Ewing/PNET. FLI-1 was detected in 50% of PNET. P63 was expressed in poorly differentiated SCC (2/7) and SNUC (1/3).

Conclusions

The results of our study indicate that the integration of histopathologic findings with application of limited but highly specific markers led to the separation of carcinomas, lymphoma and melanomas from other small cell tumors. Using a panel of keratin, LCA, desmin, and HMB45 is the most practical and economic approach to accurately classify these tumors.

NUT midline carcinomas of the sinonasal tract

NUT midline carcinoma (NMC) is a highly lethal tumor defined by translocations involving the NUT gene on chromosome 15q14. NMC involves midline structures including the sinonasal tract, but its overall incidence at this midline site and its full morphologic profile are largely unknown because sinonasal tumors are not routinely tested for the NUT gene translocation. The recent availability of an immunohistochemical probe for the NUT protein now permits a more complete characterization of sinonasal NMCs. The archival files of The Johns Hopkins Hospital Surgical Pathology were searched for all cases of primary sinonasal carcinomas diagnosed from 1995 to 2011. Tissue microarrays were constructed, and NUT immunohistochemical analysis was performed. All NUT-positive cases underwent a more detailed microscopic and immunohistochemical analysis. Among 151 primary sinonasal carcinomas, only 3 (2%) were NUT positive. NUT positivity was detected in 2 of 13 (15%) carcinomas diagnosed as sinonasal undifferentiated carcinoma and in 1 of 87 (1%) carcinomas diagnosed as squamous cell carcinoma. All occurred in men (26, 33, and 48 y of age). The NMCs grew as nests and sheets of cells with a high mitotic rate and extensive necrosis. Two were entirely undifferentiated, and 1 tumor showed abrupt areas of squamous differentiation. Each case had areas of cell spindling, and 2 were heavily infiltrated by neutrophils. Immunohistochemical staining was observed for cytokeratins (3 of 3), epithelial membrane antigen (3 of 3), p63 (2 of 3), CD34 (1 of 3), and synaptophysin (1 of 3). All patients died of the disease (survival time range, 8 to 16 mo; mean, 12 mo) despite combined surgery and chemoradiation. NMC represents a rare form of primary sinonasal carcinoma, but its incidence is significantly increased in those carcinomas that exhibit an undifferentiated component. Indiscriminant analysis for evidence of the NUT translocation is unwarranted. Instead, NUT analysis can be restricted to those carcinomas that demonstrate undifferentiated areas. The availability of an immunohistochemical probe has greatly facilitated this analysis and is helping to define the full demographic, morphologic, and immunohistochemical spectrum of sinonasal NMC.