{"title":"Adult Type Lipoblastoma With a Predominantly Fibroblastic Morphology and a Novel DLEU2::PLAG1 Gene Rearrangement: Two Cases of a Rare Entity","authors":"Tyler Steidl, Michael Michal, David I. Suster","doi":"10.1002/gcc.70064","DOIUrl":"https://doi.org/10.1002/gcc.70064","url":null,"abstract":"<div>\u0000 \u0000 <p>Lipoblastoma is a benign adipocytic lesion with embryonal fat cell differentiation. The tumors most commonly occur in children, however, rare cases have been reported to occur in adults and are generally considered to represent “maturing” or long-standing lipoblastomas. Approximately 60%–80% of these tumors harbor a gene fusion involving the <i>PLAG1</i> gene, which is known to rearrange with numerous unique fusion partners. Herein, we present two additional cases of so-called maturing lipoblastoma with a review of the literature. Both tumors occurred in adult females and both harbored a yet-unreported <i>DLEU2</i>::<i>PLAG1</i> fusion transcript. Clinically, both tumors behaved in a benign fashion. The histology was characterized by a prominence of fibroblastic growth with only partial or minimal lipomatous components. This report serves to provide additional characterization of the clinical, histologic, and molecular features of this rare tumor type.</p>\u0000 </div>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144894207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yamato Suemitsu, Hsin-Yi Chang, Carla Saoud, Josephine K. Dermawan, Meera Hameed, Samuel Singer, William D. Tap, Cristina R. Antonescu
{"title":"Secondary Genetic Alterations in Extraskeletal Myxoid Chondrosarcoma","authors":"Yamato Suemitsu, Hsin-Yi Chang, Carla Saoud, Josephine K. Dermawan, Meera Hameed, Samuel Singer, William D. Tap, Cristina R. Antonescu","doi":"10.1002/gcc.70076","DOIUrl":"https://doi.org/10.1002/gcc.70076","url":null,"abstract":"<div>\u0000 \u0000 <p>Extraskeletal myxoid chondrosarcoma (EMC) is a rare mesenchymal neoplasm of uncertain histogenesis, characterized by recurrent gene fusions involving <i>NR4A3</i> with various gene partners (<i>EWSR1</i>, <i>TAF15, FUS</i>, etc.). Although the impact of fusion variants has been linked to histology and prognosis, no study to date has comprehensively investigated the incidence and spectrum of secondary genetic alterations (SGAs) in EMC with regard to their association with fusion type and clinical impact. Our molecular database was searched for EMC tested on a hybridization capture-based targeted matched tumor-normal DNA NGS assay (MSK-IMPACT, 341-505 gene panel). All tumors had their fusion subtype confirmed either by Archer FusionPlex and/or fluorescence in situ hybridization (FISH). Clinicopathologic data was reviewed. Eighteen EMC patients (20 samples) were selected, with a mean age of 61 years and a male: female ratio of 5:1. By molecular testing, the most common <i>NR4A3</i> fusion subtype involved <i>EWSR1</i> (14/18, 78%), while two cases involved <i>TAF15</i> gene partner, and one each <i>TCF12</i> and <i>FUS</i> genes, respectively. All cases showed a low tumor mutation burden (TMB) (0–2, mean 0.83). Two-thirds of cases had concurrent SGAs, while the remaining showed only the driver <i>NR4A3</i> fusion (0–8, mean 1.67 mut/case). Among the detected SGAs, only <i>TP53</i> alterations were recurrent, seen in 2 cases with <i>EWSR1::NR4A3</i> and <i>TAF15::NR4A3</i> fusions, respectively. Other non-recurrent alterations involved <i>CDKN1B</i>, <i>TERT</i>, and <i>MET</i> genes, among others. Non-<i>EWSR1</i> fusion variant tumors showed a tendency for a higher number of SGAs compared to <i>EWSR1</i>-rearranged tumors (mean 2.75 versus 1.36 mut/case). Patients with ≥ 1 SGA showed lower disease-free survival (DFS) (<i>p</i> = 0.022) and poor overall survival (OS) (<i>p</i> = 0.014), while no statistically significant correlation was detected between OS and fusion subtypes. Most patients (83%) developed distant metastases, which did not correlate with the SGA status. This is the first study addressing the genomic landscape in EMC with regard to prognostication beyond fusion subtypes and histology. Similar to other translocation-associated sarcomas, the number of co-occurring SGAs in EMC is low; however, when present, they are associated with worse survival. Although a higher number of SGAs showed a trend to be associated with non-<i>EWSR1</i> fusion variants, larger multi-institutional studies are needed to further evaluate the correlation between fusion variants with SGAs and survival.</p>\u0000 </div>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144869681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhengyu Samuel Chua, Michael Michal, Fredrik Petersson
{"title":"TFE3-Altered Perivascular Epithelioid Cell Tumour (PEComa) of the Nasal Cavity With a Novel TRAF3::TFE3 Fusion—A Report of a Case Expanding the Molecular Genetic Spectrum and a Brief Literature Review on PEComas of the Head and Neck Region","authors":"Zhengyu Samuel Chua, Michael Michal, Fredrik Petersson","doi":"10.1002/gcc.70075","DOIUrl":"https://doi.org/10.1002/gcc.70075","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Perivascular epithelioid cell tumours (PEComas) constitute a unique group of neoplasms with a distinctive myomelanocytic immunohistochemical phenotype and uncommonly occur in the head and neck region. We herein report the clinicopathologic features of a case of a sinonasal PEComa occurring in an 18-year-old male with a novel <i>TRAF3::TFE3</i> fusion.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Case Presentation</h3>\u0000 \u0000 <p>The patient presented with an infiltrative nasal cavity tumour. Histologic examination showed a tumour composed of sheets and nests of epithelioid cells with clear to eosinophilic granular cytoplasm, round to oval nuclei, inconspicuous nucleoli and no mitotic activity. The tumour cells featured strong diffuse expression of smooth muscle actin and nuclear TFE3, with patchy expression of HMB45. Neoplastic cells showed no immune-reactivity for Melan A. Molecular genetic analysis revealed a novel <i>TRAF3(ex8)::TFE3(ex6)</i> fusion.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This report contributes to the expanding molecular spectrum of <i>TFE3</i>-altered PEComas of the head and neck region and discusses the differential diagnoses of these tumours. We further describe the evolving understanding of <i>TFE3</i>-altered PEComas.</p>\u0000 </section>\u0000 </div>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144861904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jerome Givi, Daisy Wu, Rania Bakkar, Michelle Afkhami, Diana Bell
{"title":"Pseudoglandular Schwannoma With FUS::KLF17 Fusion: Broadening the Spectrum of FUS-Associated Tumors","authors":"Jerome Givi, Daisy Wu, Rania Bakkar, Michelle Afkhami, Diana Bell","doi":"10.1002/gcc.70077","DOIUrl":"https://doi.org/10.1002/gcc.70077","url":null,"abstract":"<p>We present a case of a 51-year-old male with a pseudoglandular cellular schwannoma arising from the brachial plexus, which contains the expected molecular aberrations for a schwannoma (chromosome 22q loss encompassing the <i>NF2</i> and <i>LZTR1</i> genes) as well as a <i>FUS</i>::<i>KLF17</i> rearrangement. Pseudoglandular schwannomas are rare morphologic variants of schwannomas that contain gland-like spaces lined by S100-positive, cytokeratin-negative pseudocolumnar Schwann cells. Fusions involving <i>FUS</i> and <i>EWSR</i> are commonly found in myoepithelial tumors of bone and soft tissue. While the spectrum of tumors with fusions involving <i>FUS</i> and <i>EWSR</i> is relatively broad, no cases, to our knowledge, have been reported of schwannomas, let alone the morphologically distinct pseudoglandular schwannoma, containing a <i>FUS</i> rearrangement. This case thus expands the spectrum of <i>FUS</i> rearranged tumors, highlighting the need for documentation of similar cases to understand the clinical significance of this combination.</p>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gcc.70077","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eric C. Honaker, Laura M. Warmke, Ameline Baptiste, Daniel Baumhoer, Esther Baranov, Eitan Halper-Stromberg, Carina A. Dehner
{"title":"CD34-Positive Acral Chondromyxoid Mesenchymal Neoplasm Harboring a Novel TCF4::ERG Fusion","authors":"Eric C. Honaker, Laura M. Warmke, Ameline Baptiste, Daniel Baumhoer, Esther Baranov, Eitan Halper-Stromberg, Carina A. Dehner","doi":"10.1002/gcc.70073","DOIUrl":"https://doi.org/10.1002/gcc.70073","url":null,"abstract":"<p>Molecular testing has significantly transformed the field of anatomic pathology over the past several decades. Despite these advances, acral mesenchymal neoplasms remain diagnostically challenging, requiring careful integration of clinical presentation, histologic features, and molecular findings for accurate classification. Herein, we present a case of an acral chondromyxoid mesenchymal neoplasm harboring a novel in-frame <i>TCF4::ERG</i> fusion involving the right index finger of a 26-year-old female. Morphologically, this tumor consisted of nests and sheets of monotonous small round-to-ovoid cells embedded in a background of chondromyxoid stroma and hyalinized collagen. The tumor cells were diffusely CD34, ERG, and focally p63 reactive, while S100 protein, cytokeratin AE1/AE3, Pan-TRK, ALK, smooth muscle actin, and desmin were negative. Albeit short follow-up (3 months), the patient continues to do well without evidence of metastasis or local recurrence.</p>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gcc.70073","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Usui, N. Nakamura, E. Katayama, A. Sato, T. Mukouyama, N. Sakai, S. Otsuka, R. Okuya, Y. Habu, K. Nishikimi, S. Tate, J. Ikeda, K. Koga
{"title":"Macroscopic Monozygotic Androgenetic/Biparental Mosaicism: Molecular Characterization and Clinical Implications","authors":"H. Usui, N. Nakamura, E. Katayama, A. Sato, T. Mukouyama, N. Sakai, S. Otsuka, R. Okuya, Y. Habu, K. Nishikimi, S. Tate, J. Ikeda, K. Koga","doi":"10.1002/gcc.70078","DOIUrl":"https://doi.org/10.1002/gcc.70078","url":null,"abstract":"<div>\u0000 \u0000 <p>Hydatidiform moles represent abnormal pregnancies characterized by trophoblastic hyperproliferation. However, accurate diagnosis of partial hydatidiform moles (PHM) remains challenging. We present a rare case of a monozygotic androgenetic/biparental mosaic in a 26-year-old primigravida. The patient was referred to our institution for a suspected PHM, and ultrasonography revealed a nonviable embryo-like structure alongside villous formations with focal cystic changes. Pathological examination of the evacuated tissue revealed the coexistence of normal and hydropic villi. Histological assessment with p57KIP2 immunohistochemistry initially suggested PHM; however, some cytotrophoblasts and villous stromal cells were negative for p57KIP2 immunoreactivity. Therefore, we conducted short tandem repeat analysis separately for normal villous tissue and cystic villous lesions to elucidate the genetic origin of this unusual presentation. The normal villous portion exhibited biparental diploidy, whereas the cystic villous portion exhibited androgenetic monospermic patterns. Comparisons across all 16 loci revealed concordance between the paternal alleles of biparental diploid villi and the androgenic molar alleles, indicating a single sperm origin. SNP array analysis with B allele frequency plotting confirmed these findings at the whole-genome level; normal villi showed biparental diploid patterns, whereas cystic villi displayed uniparental disomic patterns. These results demonstrate that both components originated from a monozygotic conception rather than from dizygotic twinning. Therefore, we propose a clinical category based on the sequelae of endoduplication and the formation of a tripolar spindle apparatus through the first meiotic division, encompassing macroscopic androgenetic/biparental mosaicism, twin pregnancy with a hydatidiform mole, microscopic androgenetic/biparental mosaicism, and confined placental mosaicism. Given the presence of androgenetic elements and our institutional experience with gestational trophoblastic neoplasia development in a similar case, we recommend that such cases be managed according to complete hydatidiform mole surveillance protocols. This case highlights the diagnostic challenges posed by monozygotic androgenetic/biparental mosaic mechanisms and emphasizes the importance of molecular genetic analysis for the accurate diagnosis and appropriate clinical management of atypical hydatidiform moles.</p>\u0000 </div>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Type B3 Thymoma With a Novel KMT2A::MAML3 Fusion: Expanding the Spectrum of Gene Fusions Beyond the MAML2 Gene","authors":"Ziqi Zhou, Yanqi Yu, Conghao Chen, Jie Lin","doi":"10.1002/gcc.70071","DOIUrl":"https://doi.org/10.1002/gcc.70071","url":null,"abstract":"<div>\u0000 \u0000 <p>Mastermind-like transcriptional coactivator (<i>MAML</i>) gene fusions have been documented in Thymic Epithelial Tumors (TETs). Specifically, lysine methyltransferase 2A (<i>KMT2A)::MAML2</i> gene fusions are associated with type B2 and B3 thymomas. Here, we report for the first time a young patient with invasive type B3 thymoma harboring a novel <i>KMT2A::MAML3</i> gene fusion. <i>MAML3</i> and <i>MAML2</i> are paralogues. In addition to the classic type B3 thymoma histology, this article documents intratumor heterogeneity, characterized by a trabecular and fascicular pattern, as well as areas of clear cells. Immunohistochemistry showed keratin positivity in tumor cells, while neuroendocrine markers were negative in trabecular regions. DNA-based next-generation sequencing failed to identify pathogenic variants, but RNA sequencing detected the <i>KMT2A::MAML3</i> gene fusion. We compared the gene fusion sites of <i>MAML2</i> and <i>MAML3</i>, focusing on exon 2, and found that they share similar functional protein domains. Moreover, the same domain appeared downstream of the <i>KMT2A::MAML2</i> fusion protein. Therefore, we hypothesize that <i>MAML3</i> gene fusions, like <i>MAML2</i>, lead to abnormal Notch signaling pathways and increase the invasive potential of certain thymoma subtypes. Our findings expand the genetic landscape of aggressive thymomas and offer new insights for molecular studies in TETs.</p>\u0000 </div>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
James A Watkins, Patrick Tarpey, Maria O'Donovan, John A Tadross, Nadia Mohammed
{"title":"Widening the Spectrum of Fusion Events in Schwannoma: Identification of a Novel TANC1::HTRA1 Fusion.","authors":"James A Watkins, Patrick Tarpey, Maria O'Donovan, John A Tadross, Nadia Mohammed","doi":"10.1002/gcc.70072","DOIUrl":"10.1002/gcc.70072","url":null,"abstract":"<p><p>A range of genomic drivers have been identified in schwannomas, including a number of translocations, most commonly SH3PXD2A::HTRA1. To date, despite the analysis of large numbers of cases, no examples of variant HTRA1 partners have been described. We describe a schwannoma arising in the periportal region in which a novel TANC1::HTRA1 fusion was identified. The identification of this variant expands the range of fusion drivers in schwannoma and offers insight into the pathogenic mechanism of HTRA1 fusions and their utility in molecular diagnosis.</p>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 8","pages":"e70072"},"PeriodicalIF":2.8,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144951560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Selina Glaser, Rabea Wagener, Shannon K. Harkins, Claudia Voena, Susanne Bens, Wolfram Klapper, Camille Laurent, Stephan Mathas, Meiqi Ren, Sandrine Sander, Charlotte Schnaudt-Mastrangelo, Wilhelm Wößmann, Luc Xerri, Ole Ammerpohl, Andrew D. Zelenetz, Abner Louissaint Jr, Roberto Chiarle, Reiner Siebert
{"title":"Comparative DNA Methylation Profiling of Human and Murine ALK-Positive B-Cell Neoplasms","authors":"Selina Glaser, Rabea Wagener, Shannon K. Harkins, Claudia Voena, Susanne Bens, Wolfram Klapper, Camille Laurent, Stephan Mathas, Meiqi Ren, Sandrine Sander, Charlotte Schnaudt-Mastrangelo, Wilhelm Wößmann, Luc Xerri, Ole Ammerpohl, Andrew D. Zelenetz, Abner Louissaint Jr, Roberto Chiarle, Reiner Siebert","doi":"10.1002/gcc.70060","DOIUrl":"https://doi.org/10.1002/gcc.70060","url":null,"abstract":"<p>Structural genomic variants leading to anaplastic lymphoma kinase (ALK) gene fusions and aberrant expression of the ALK tyrosine kinase are the hallmark of subtypes of T- and B-lineage neoplasms, namely ALK-positive anaplastic large lymphoma (ALCL) and ALK-positive large B-cell lymphoma (LBCL). The latter is a rare aggressive lymphoma, which has been initially identified as a variant of diffuse LBCL (DLBCL) with plasmablastic features. Here, we performed comparative DNA methylation profiling of human and murine ALK-positive B-cell neoplasms. Array-based DNA methylation data from ALK-positive LBCL samples of eight patients were compared to that of DLBCL (<i>n</i> = 75), multiple myeloma (MM, <i>n</i> = 24), ALK-positive ALCL (<i>n</i> = 12) and normal B-cell populations (<i>n</i> = 93). ALK-positive LBCLs share a distinct DNA methylation signature similar to that of MM, characterized by lower global DNA methylation levels compared to DLBCLs and normal B-cell populations. DNA methylation alterations in ALK-positive LBCL were predominantly located in heterochromatic and polycomb-repressed regions. The epigenetic age and relative proliferative history of ALK-positive LBCL were intermediate between MM and DLBCL. B-cell neoplasms in <i>NPM</i>::<i>ALK</i> transgenic mice showed a similar hypomethylated signature when compared to normal murine B cells. Cross-species comparison indicated conservation of chromatin states and pathways affected by hypomethylation. Together, the findings suggest that in line with their phenotypical appearance human and murine ALK-positive B-cell lymphomas share an epigenetic profile more closely resembling that of plasma cell neoplasias than that of DLBCLs.</p>","PeriodicalId":12700,"journal":{"name":"Genes, Chromosomes & Cancer","volume":"64 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gcc.70060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}