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Dehner CA, Rudzinski ER, Davis JL. Rhabdomyosarcoma: Updates on classification and the necessity of molecular testing beyond immunohistochemistry. Hum Pathol 2024; 147:72-81. [PMID: 38135061 DOI: 10.1016/j.humpath.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/06/2023] [Accepted: 12/19/2023] [Indexed: 12/24/2023]
Abstract
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents under the age of 20. The current World Health Organization (WHO) classification for soft tissue and bone tumors recognizes 4 distinct subtypes of RMS based on clinicopathological and molecular genetic features: embryonal, alveolar, spindle cell/sclerosing and pleomorphic subtypes. However, with the increased use of molecular techniques, the classification of rhabdomyosarcoma has been evolving rapidly. New subtypes such as osseus RMS harboring TFCP2/NCOA2 fusions or RMS arising in inflammatory rhabdomyoblastic tumor have been emerging within the last decade, adding to the complexity of diagnosing skeletal muscle tumors. This review article provides an overview of classically recognized distinctive subtypes as well as new, evolving subtypes and discusses important morphologic, immunophenotypic and molecular genetic features of each subtype including recommendations for a diagnostic approach of malignant skeletal muscle neoplasms.
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Affiliation(s)
- Carina A Dehner
- Department of Pathology & Laboratory Medicine, Indiana University, Indianapolis, IN, USA
| | - Erin R Rudzinski
- Department of Laboratories, Seattle Children's Hospital and Department of Laboratory Medicine and Pathology, University of Washington Medical Center, Seattle, WA, USA
| | - Jessica L Davis
- Department of Pathology & Laboratory Medicine, Indiana University, Indianapolis, IN, USA.
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Warmke LM, Mustafa A, Zou YS, Davis JL, Ulbright TM, Segura SE. Myxoid epithelioid smooth muscle tumor of the vulva: A distinct entity with MEF2D::NCOA2 gene fusion. Genes Chromosomes Cancer 2024; 63:e23209. [PMID: 37870842 DOI: 10.1002/gcc.23209] [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: 09/06/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/24/2023] Open
Abstract
Smooth muscle tumors are the most common mesenchymal tumors of the female genital tract, including the vulva. Since vulvar smooth muscle tumors are rare, our understanding of them compared to their uterine counterparts continues to evolve. Herein, we present two cases of morphologically distinct myxoid epithelioid smooth muscle tumors of the vulva with novel MEF2D::NCOA2 gene fusion. The tumors involved 24 and 37-year-old women. Both tumors presented as palpable vulvar masses that were circumscribed, measuring 2.8 and 5.1 cm in greatest dimension. Histologically, they were composed of epithelioid to spindle-shaped cells with minimal cytologic atypia and prominent myxoid matrix. Rare mitotic figures were present (1-3 mitotic figures per 10 high-power field (HPF)), and no areas of tumor necrosis were identified. By immunohistochemistry, the neoplastic cells strongly expressed smooth muscle actin, calponin, and desmin, confirming smooth muscle origin. Next-generation sequencing identified identical MEF2D::NCOA2 gene fusions. These two cases demonstrate that at least a subset of myxoid epithelioid smooth muscle tumors of the vulva represent a distinct entity characterized by a novel MEF2D::NCOA2 gene fusion. Importantly, recognition of the distinct morphologic and genetic features of these tumors is key to understanding the biological potential of these rare tumors.
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Affiliation(s)
- Laura M Warmke
- Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Amin Mustafa
- Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Ying S Zou
- Department of Pathology, The Johns Hopkins Hospital, Baltimore, Maryland, USA
| | - Jessica L Davis
- Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Thomas M Ulbright
- Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Sheila E Segura
- Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Tauziède-Espariat A, Hasty L, Métais A, Varlet P. Mesenchymal non-meningothelial tumors of the central nervous system: a literature review and diagnostic update of novelties and emerging entities. Acta Neuropathol Commun 2023; 11:22. [PMID: 36737790 PMCID: PMC9896826 DOI: 10.1186/s40478-023-01522-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 01/25/2023] [Indexed: 02/05/2023] Open
Abstract
The fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System (CNS) now includes mesenchymal tumors that occur uniquely or frequently in the CNS. Moreover, this version has aligned the terminology of mesenchymal tumors with their soft tissue counterparts. New tumor types have been added, such as the "intracranial mesenchymal tumor, FET-CREB fusion-positive", the "CIC-rearranged sarcoma", and the "Primary intracranial sarcoma, DICER1-mutant". Other entities (such as rhabdomyosarcoma) have remained in the current WHO classification because these tumor types may present specificities in the CNS as compared to their soft tissue counterparts. Based on an extensive literature review, herein, we will discuss these newly recognized entities in terms of clinical observation, radiology, histopathology, genetics and outcome, and consider strategies for an accurate diagnosis. In light of this literature analysis, we will also introduce some potentially novel tumor types.
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Affiliation(s)
- Arnault Tauziède-Espariat
- Department of Neuropathology, Sainte-Anne Hospital, 1, rue Cabanis, 75014, Paris, France. .,Inserm, UMR 1266, IMA-Brain, Institut de Psychiatrie et Neurosciences de Paris, Paris, France.
| | - Lauren Hasty
- grid.414435.30000 0001 2200 9055Department of Neuropathology, Sainte-Anne Hospital, 1, rue Cabanis, 75014 Paris, France ,grid.512035.0Inserm, UMR 1266, IMA-Brain, Institut de Psychiatrie et Neurosciences de Paris, Paris, France
| | - Alice Métais
- grid.414435.30000 0001 2200 9055Department of Neuropathology, Sainte-Anne Hospital, 1, rue Cabanis, 75014 Paris, France ,grid.512035.0Inserm, UMR 1266, IMA-Brain, Institut de Psychiatrie et Neurosciences de Paris, Paris, France
| | - Pascale Varlet
- grid.414435.30000 0001 2200 9055Department of Neuropathology, Sainte-Anne Hospital, 1, rue Cabanis, 75014 Paris, France ,grid.512035.0Inserm, UMR 1266, IMA-Brain, Institut de Psychiatrie et Neurosciences de Paris, Paris, France
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Han R, Dermawan JK, Demicco EG, Ferguson PC, Griffin AM, Swanson D, Antonescu CR, Dickson BC. ZFP64::NCOA3 gene fusion defines a novel subset of spindle cell rhabdomyosarcoma. Genes Chromosomes Cancer 2022; 61:645-652. [PMID: 35521817 PMCID: PMC9811222 DOI: 10.1002/gcc.23052] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/28/2022] [Accepted: 05/02/2022] [Indexed: 01/07/2023] Open
Abstract
Spindle cell rhabdomyosarcoma represents a rare neoplasm characterized by monomorphic spindle cells with a fascicular architecture and variable skeletal muscle differentiation. Following incidental identification of a ZFP64::NCOA3 gene fusion in an unclassified spindle cell sarcoma resembling adult-type fibrosarcoma, we performed a retrospective archival review and identified four additional cases with a similar histology and identical gene fusion. All tumors arose in adult males (28-71 years). The neoplasms were found in the deep soft tissues, two were gluteal, and one each arose in the thigh, abdominal wall, and chest wall. Morphologically, the tumors were characterized by spindle cells with a distinctive herringbone pattern and variable collagenous to myxoid stroma. The nuclei were relatively monomorphic with variable mitotic activity. Three tumors had immunoreactivity for MyoD1, and four contained variable expression of desmin and smooth muscle actin. All cases tested for myogenin, CD34, S100, pankeratin, and epithelial membrane antigen were negative. Targeted RNA sequencing revealed a ZFP64::NCOA3 fusion product in all five tumors. Three patients developed distant metastases, and two ultimately succumbed to their disease within 2 years of initial diagnosis. This study suggests ZFP64::NCOA3 fusions define a novel subtype of rhabdomyosarcoma with a spindle cell morphology and aggressive clinical behavior. The potential for morphologic and immunohistochemical overlap with several other sarcoma types underscores the value of molecular testing as a diagnostic adjunct to ensure accurate classification and management of these neoplasms.
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Affiliation(s)
- Rachel Han
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | | | - Elizabeth G. Demicco
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
| | - Peter C. Ferguson
- Division of Orthopaedics, Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Anthony M. Griffin
- Division of Orthopaedics, Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - David Swanson
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
| | | | - Brendan C. Dickson
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
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