title: A well-differentiated liposarcoma with a new type of chromosome 12-derived markers.
abstract: Well-differentiated liposarcomas (WDLPS) are cytogenetically characterized by the presence of supernumerary ring or giant rod marker chromosomes. These supernumerary chromosomes are composed of amplified sequences from chromosome 12 (12q14 approximately 15) in association with amplified segments from various other chromosomes, and contain alterations of the alpha satellite sequences. We report a case of WDLPS of the lipoma-like and sclerosing subtype that contains a novel type of supernumerary marker chromosome. Instead of rings or giant rods, these cells had three apparently identical copies of a subtelocentric supernumerary marker with a size and shape similar to C-group chromosomes. Fluorescence in situ hybridization analysis revealed that the markers were composed of amplified material from 12q14 approximately 15, including the genes MDM2 and CDK4. Similar to the rings and giant rods observed in other WDLPS cases, these unusual markers had no alpha satellite repeats at the primary constriction site, but centromeric activity could be demonstrated by using anti-centromere protein C antibodies. These findings show that the supernumerary markers of WDLPS may be variable in size and shape, but consistently share the same genomic structure, specifically 12q amplified sequences together with centromere alterations, and underline the importance of molecular methods in the diagnosis of adipose tissue tumors.
authors.affiliation: Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, 0310, Oslo, Norway. anne.forus@labmed.uio.no
authors.forename: A
authors.initials: A
authors.lastname: Forus
authors.forename: B
authors.initials: B
authors.lastname: Bjerkehagen
authors.forename: N
authors.initials: N
authors.lastname: Sirvent
authors.forename: L A
authors.initials: LA
authors.lastname: Meza-Zepeda
authors.forename: J M
authors.initials: JM
authors.lastname: Coindre
authors.forename: J M
authors.initials: JM
authors.lastname: Berner
authors.forename: O
authors.initials: O
authors.lastname: Myklebost
authors.forename: F
authors.initials: F
authors.lastname: Pedeutour
mesh_terms: D000368:Aged; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D020732:Cytogenetic Analysis / Q000379:methods*; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008080:Liposarcoma / Q000235:genetics* / Q000473:pathology*; D008677:Metaphase; D009693:Nucleic Acid Hybridization; D012186:Retroperitoneal Neoplasms / Q000235:genetics
chemical_list: D005819:Genetic Markers