title: Malignant peripheral nerve sheath tumor with a t(X;18).
abstract: We describe an ankle tumor arising in a 16-year-old girl. The tumor demonstrated histology typical of a malignant peripheral nerve sheath tumor (MPNST), but exhibited a variant form of the (X;18) translocation associated with synovial sarcoma. Immunohistochemical stains were positive for vimentin, CD57, collagen type IV, and Bcl-2. Routine and molecular cytogenetic studies showed an unbalanced 3-way chromosomal translocation that involved chromosomes X, 18, and 1. Electron microscopic findings were noncontributory. This unusual tumor raises the following questions and possibilities: (1) As the t(X;18) suggests, could this tumor be a monophasic synovial sarcoma with the histologic features of an MPNST? (2) Or, as the histology suggests, is this tumor an MPNST that has a t(X;18)? (3) Finally, could MPNST histology, a t(X;18), and no defining immunohistochemical or electron microscopic features represent an as yet unrecognized part of a spectrum that spans from synovial sarcoma to MPNST or other spindle cell tumors?
authors.affiliation: University of Texas Medical School, Department of Pathology and Laboratory Medicine, Houston 77030, USA.
authors.forename: R
authors.initials: R
authors.lastname: Vang
authors.forename: D A
authors.initials: DA
authors.lastname: Biddle
authors.forename: W R
authors.initials: WR
authors.lastname: Harrison
authors.forename: K
authors.initials: K
authors.lastname: Heck
authors.forename: L D
authors.initials: LD
authors.lastname: Cooley
mesh_terms: D000293:Adolescent; D018959:CD57 Antigens / Q000032:analysis; D002874:Chromosome Mapping; D002887:Chromosomes, Human, Pair 18; D003094:Collagen / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007621:Karyotyping; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology / Q000601:surgery / Q000648:ultrastructure; D018317:Nerve Sheath Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D012086:Reoperation; D013584:Sarcoma, Synovial / Q000235:genetics* / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D014178:Translocation, Genetic; D014746:Vimentin / Q000032:analysis; D014960:X Chromosome
chemical_list: D018959:CD57 Antigens; D019253:Proto-Oncogene Proteins c-bcl-2; D014746:Vimentin; D003094:Collagen