title: Lack of SYT-SSX fusion transcripts in malignant peripheral nerve sheath tumors on RT-PCR analysis of 34 archival cases.
abstract: The translocation t(X;18) is currently regarded as a specific molecular marker of synovial sarcoma (SS). Recently, however, it has been reported that malignant peripheral nerve sheath tumors expressed this marker in 75% of the cases. To test independently this iconoclastic claim, a molecular analysis for the detection of the SYT-SSX fusion genes was carried out using archival material of 34 consecutive cases diagnosed as malignant peripheral nerve sheath tumors and treated in our Institute from 1998 to 2000. In four of these cases, the molecular analysis on fixed tissues was supplemented with an analysis on fresh frozen tissue. RNA extracted from formalin-fixed paraffin-embedded tissue blocks was evaluated for the presence of SYT-SSX1 and SYT-SSX2 fusion transcripts by RT-PCR. This analysis was extended to a wide variety of normal tissues simultaneously extracted and equally processed. Only two of the cases studied harbored SYT-SSX1 and SYT-SSX2 fusion transcripts, respectively. The diagnostic reevaluation of these two cases in light of the molecular data disclosed that one had the features of a monophasic SS and the other was compatible with that entity. Both of these tumors were strongly immunoreactive for bcl-2, confirming the diagnostic utility of this marker in this instance. Our results reaffirm the specificity of SYT-SSX for SS and suggest that an opposite claim made in a recent study may have been due to a faulty interpretation of the molecular results caused by a contamination of the samples.
authors: Department of Pathology, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milano, Italy.
authors: Elena
authors: E
authors: Tamborini
authors: Viviana
authors: V
authors: Agus
authors: Federica
authors: F
authors: Perrone
authors: Daniela
authors: D
authors: Papini
authors: Roberta
authors: R
authors: Romanò
authors: Barbara
authors: B
authors: Pasini
authors: Alessandro
authors: A
authors: Gronchi
authors: Maurizio
authors: M
authors: Colecchia
authors: Juan
authors: J
authors: Rosai
authors: Marco A
authors: MA
authors: Pierotti
authors: Silvana
authors: S
authors: Pilotti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000032:analysis; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D018317:Nerve Sheath Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D015514:Oncogene Proteins, Fusion; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C116512:SYT-SSX fusion protein