Carrillo-Ng H, Liang Y, Chang S, Afkhami M, Gernon T, Bell D, Arias-Stella JA. Complete mimicry: Rhabdomyosarcoma with FUS::TFCP2 fusion masquerading as carcinoma-diagnostic challenge and report of two cases.
Genes Chromosomes Cancer 2023;
62:430-436. [PMID:
37057803 DOI:
10.1002/gcc.23145]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 04/04/2023] [Indexed: 04/15/2023] Open
Abstract
Rhabdomyosarcomas (RMS) are malignant mesenchymal tumors with skeletal muscle differentiation which are classified into alveolar, embryonal, pleomorphic, and spindle cell/sclerosing RMS. Within the spindle cell/sclerosing RMS tumor type there is a recently recognized sub-type categorized as intraosseous spindle cell RMS with TFCP2/NCOA2 gene fusion. This rare tumor is highly aggressive with predominant involvement of the craniofacial and pelvic bones with approximately 30 cases reported to date. Histopathologic features include spindle cell and epithelioid morphology with a characteristic co-expression of epithelial markers, myogenic markers, and ALK1 expression. We report two cases of gnathic spindle cell/sclerosing RMS with FUS::TFCP2 gene fusion that were initially interpreted as carcinomas by referring institutions and later reclassified when encountered in our practice after additional work-up and molecular characterization.
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