title: Malignant peripheral nerve sheath tumors with t(X;18). A pathologic and molecular genetic study.
abstract: Spindle cell sarcomas often present the surgical pathologist with a considerable diagnostic challenge. Malignant peripheral nerve sheath tumor, leiomyosarcoma, fibrosarcoma, and monophasic synovial sarcoma may all appear similar histologically. The application of ancillary diagnostic modalities, such as immunohistochemistry and electron microscopy, may be helpful in the differentiation of these tumors, but in cases in which these adjunctive techniques fail to demonstrate any more definitive evidence of differentiation, tumor categorization may remain difficult. Cytogenetic and molecular genetic characterization of tumors have provided the basis for the application of molecular assays as the newest components of the diagnostic armamentarium. Because the chromosomal translocation t(X;18) has been observed repeatedly in many synovial sarcomas, it has been heralded as a diagnostic hallmark of synovial sarcoma. To formally test the specificity of this translocation for the diagnosis of synovial sarcoma, RNA extracted from formalin-fixed, paraffin-embedded tissue from a variety of soft tissue and spindle cell tumors was evaluated for the presence of t(X;18) by reverse transcriptase-polymerase chain reaction. Although 85% of the synovial sarcomas studied demonstrated t(X;18), 75% of the malignant peripheral nerve sheath tumors in our cohort also demonstrated this translocation. We conclude that the translocation t(X;18) is not specific to synovial sarcoma and discuss the implications of the demonstration of t(X;18) in a majority of malignant peripheral nerve sheath tumors.
authors.affiliation: L.V. Ackerman Laboratory of Surgical Pathology, Washington University Medical Center, St. Louis, Missouri 63110, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: M
authors.initials: M
authors.lastname: Kyriakos
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: M R
authors.initials: MR
authors.lastname: Wick
authors.forename: P E
authors.initials: PE
authors.lastname: Swanson
authors.forename: L P
authors.initials: LP
authors.lastname: Dehner
authors.forename: P A
authors.initials: PA
authors.lastname: Humphrey
authors.forename: J D
authors.initials: JD
authors.lastname: Pfeifer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D008967:Molecular Biology; D018317:Nerve Sheath Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D010524:Peripheral Nervous System Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D013584:Sarcoma, Synovial / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D014178:Translocation, Genetic
chemical_list: D004273:DNA, Neoplasm