title: Cryptic SYT/SXX1 fusion gene in high-grade biphasic synovial sarcoma with unique complex rearrangement and extensive BCL2 overexpression.
abstract: Synovial sarcomas are high-grade malignant mesenchymal tumors that account for 10% of all soft-tissue sarcomas. Almost 95% of these tumors are characterized by a nonrandom chromosomal abnormality, t(X;18)(p11.2;q11.2), that is observed in both biphasic and monophasic variants. In this article, we present the case of a 57-year-old woman diagnosed with high-grade biphasic synovial sarcoma in which conventional cytogenetic analysis revealed the constant presence of a unique t(18;22)(q12;q13), in addition to trisomy 8. The rearrangement was confirmed by fluorescence in situ hybridization. The use of the whole chromosome painting probes WCPX did not detect any rearrangements involving chromosome X, although reverse-transcriptase polymerase chain reaction (PCR) analysis demonstrated the conspicuous presence of a SYT/SXX1 fusion gene. Spectral karyotyping (SKY) was also performed and revealed an insertion of material from chromosome 18 into one of the X chromosomes at position Xp11.2. Thus, the karyotype was subsequently interpreted as 47,X,der(X)ins(X;18)(p11.2;q11.2q11.2),der(18)del(18)(q11.2q11.2)t(18;22)(q12;q13),der(22)t(18;22). Real-time PCR analysis of BCL2 expression in the tumor sample showed a 433-fold increase. This rare finding exemplifies that thorough molecular-cytogenetic analyses are required to elucidate complex and/or cryptic tumor-specific translocations.
authors.affiliation: Division of Pediatric Oncology, Department of Pediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Bloco G. Av. Bandeirantes, 3900, Bairro Monte Alegre, CEP 14048-900, Ribeirão Preto - São Paulo, Brazil. marsol@rge.fmrp.usp.br
authors.forename: María Sol
authors.initials: MS
authors.lastname: Brassesco
authors.forename: Maria Angélica
authors.initials: MA
authors.lastname: Cortez
authors.forename: Elvis Terci
authors.initials: ET
authors.lastname: Valera
authors.forename: Edgard Eduard
authors.initials: EE
authors.lastname: Engel
authors.forename: Marcello Henrique
authors.initials: MH
authors.lastname: Nogueira-Barbosa
authors.forename: Aline Paixão
authors.initials: AP
authors.lastname: Becker
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Scrideli
authors.forename: Luiz Gonzaga
authors.initials: LG
authors.lastname: Tone
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D050939:Gene Fusion; D015321:Gene Rearrangement; D019254:Genes, bcl-2; D006801:Humans; D008875:Middle Aged; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000235:genetics*
chemical_list: D017931:DNA Primers; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; C093961:SS18 protein, human