title: Cytogenetic and molecular cytogenetic findings in giant dedifferentiated             liposarcoma of the thigh.
abstract: Non-retroperitoneal dedifferentiated liposarcoma (DDLS) is relatively uncommon and its characterization at the molecular genetic level has been limited. We describe the cyto-genetic and molecular cytogenetic findings of giant DDLS arising in the right thigh of an 83-year-old woman. Magnetic resonance imaging revealed a mass composed of two components with heterogeneous signal intensities, suggesting the coexistence of a fatty area and another soft tissue component. A wide resection of the tumor was performed. The resected, grossly heterogeneous mass, measuring 26x18x8 cm, was histopathologically composed of a well-differentiated liposarcomatous component transitioning abruptly into a dedifferentiated one. Cytogenetic analysis exhibited a complex karyotype with several numerical and structural alterations, including ring and giant marker chromosomes. Metaphase-based comparative genomic hybridization analysis showed high-level amplifications of 1q21-q25 and 12q13-q21. Interphase fluorescence in situ hybridization analysis revealed MDM2 and CDK4 gene amplification in both the well-differentiated and dedifferentiated components. These findings indicate that DDLS of the extremity shares a similar genetic background to retroperitoneal DDLS.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan. jnishio@cis.fukuoka-u.ac.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Nishio
authors.forename: Mikiko
authors.initials: M
authors.lastname: Aoki
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nabeshima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Naito
mesh_terms: D000369:Aged, 80 and over; D002454:Cell Differentiation / Q000235:genetics; D002877:Chromosomes, Human; D055028:Comparative Genomic Hybridization; D051358:Cyclin-Dependent Kinase 4 / Q000235:genetics; D020732:Cytogenetic Analysis / Q000379:methods; D003582:Cytogenetics / Q000379:methods; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D008080:Liposarcoma / Q000235:genetics* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics; D012186:Retroperitoneal Neoplasms / Q000235:genetics / Q000473:pathology; D013848:Thigh
chemical_list: C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4