title: Retroperitoneal dedifferentiated liposarcoma lacking MDM2 amplification in a patient with a germ line CHEK2 mutation.
abstract: Germ line mutations in genes that encode proteins involved in the DNA damage response predispose patients to a variety of tumors. Checkpoint kinase 2, encoded by the CHEK2 gene, is important in transducing the DNA damage response. Germ line CHEK2 mutations are seen in a subset of patients with a familial breast cancer and sarcoma phenotype. We report a case of retroperitoneal dedifferentiated liposarcoma in a 61-year-old female with germ line CHEK2 mutation. MDM2 gene amplification normally present and used to aid in the diagnosis of retroperitoneal dedifferentiated liposarcoma was absent in this case. Lack of MDM2 overexpression has similarly been reported in liposarcomas arising in patients with germ line TP53 mutations. We propose this case may highlight a nonamplified MDM2 phenotype in well- and dedifferentiated liposarcomas arising in patients with germ line mutations of genes involved in p53-associated DNA damage response pathways.
authors.affiliation: Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, 19104, USA, navid.sadri@uphs.upenn.edu.
authors.forename: Navid
authors.initials: N
authors.lastname: Sadri
authors.forename: Lea F
authors.initials: LF
authors.lastname: Surrey
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Fraker
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Zhang
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics; D064447:Checkpoint Kinase 2 / Q000235:genetics*; D005260:Female; D005784:Gene Amplification; D018095:Germ-Line Mutation; D006801:Humans; D008080:Liposarcoma / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics*
chemical_list: C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; D064447:Checkpoint Kinase 2