SRF Fusions Other Than With RELA Expand the Molecular Definition of SRF-fused Perivascular Tumors.
Am J Surg Pathol
; 44(12): 1725-1735, 2020 12.
Article
em En
| MEDLINE
| ID: mdl-33021523
ABSTRACT
Pericytic tumors encompass several entities sharing morphologic and immunohistochemical features. A subset of perivascular myoid tumors associated with the SRF-RELA fusion gene was previously described. Herein, we report a series of 13 tumors belonging to this group, in which we have identified new fusion genes by RNA-sequencing, thus expanding the molecular spectrum of this entity. All patients except 1 were children and infants. The tumors, frequently located in the head (n=8), had a mean size of 38 mm (range 10 to 150 mm) and were mostly (n=9) well-circumscribed. Exploration of the follow-up data (ranging from 3 to 68 mo) confirmed the benign behavior of these tumors. These neoplasms presented a spectrum of morphologies, ranging from perivascular patterns to myoid appearance. Tumor cells presented mitotic figures but without marked atypia. Some of these tumors could mimic sarcoma. The immunohistochemical profiles confirmed a pericytic differentiation with the expression of the smooth muscle actin and the h-caldesmon, as well as the frequent positivity for pan-cytokeratin. The molecular analysis identified the expected SRF-RELA fusion gene, in addition to other genetic alterations, all involving SRF fused to CITED1, CITED2, NFKBIE, or NCOA2. The detection of SRF-NCOA2 fusions in spindle cell rhabdomyosarcoma of the infant has previously been described, representing a risk of misdiagnosis, although the cases reported herein did not express MyoD1. Finally, clustering analyses confirmed that this group of SRF-fused perivascular myoid tumors forms a distinct entity, different from other perivascular tumors, spindle cell rhabdomyosarcomas of the infant, and smooth muscle tumors.
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Base de dados:
MEDLINE
Assunto principal:
Biomarcadores Tumorais
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Neoplasias de Tecido Conjuntivo e de Tecidos Moles
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Fator de Resposta Sérica
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Fator de Transcrição RelA
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Fusão Gênica
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article