title: p53+/mdm2- atypical lipomatous tumor/well-differentiated liposarcoma in young children: an early expression of Li-Fraumeni syndrome.
abstract: The spectrum of lipomatous tumors differs in the adult and pediatric populations, with liposarcoma being rare in children. Nearly 10% of individuals with Li-Fraumeni syndrome develop sarcomas in the first 2 decades of life; however, the frequency of sarcoma types and subtypes in this syndrome is unknown. Two atypical lipomatous tumors/well-differentiated liposarcomas (ALT/WDLS) were identified in the pathology files of our institution in young children from "classical" Li-Fraumeni and Li-Fraumeni variant kindreds with a known germline TP53 mutation (Y220C) in one of the families. The patients were 5 and 6 years of age and the ALT/WDLSs were the first expression of the syndrome. The tumors had a high degree of cellular atypia and differed from sporadic ALT/WDLS by strong nuclear immunoreactivity for p53 and absent mdm2 expression. This is the first report of 2 ALT/WDLSs presenting in children before 10 years of age, both in association with Li-Fraumeni syndrome/variant. ALT/WDLS in a young child should raise the possibility of a cancer predisposition syndrome and, in this setting, the p53(+)/mdm2(-) immunophenotype might be characteristic. Recognition of this lesion and its association is important for early diagnosis and subsequent tumor surveillance in the proband and affected family members.
authors.affiliation: Department of Pathology, Children's Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA. larisa.debelenko@stjude.org
authors.forename: Larisa V
authors.initials: LV
authors.lastname: Debelenko
authors.forename: Antonio R
authors.initials: AR
authors.lastname: Perez-Atayde
authors.forename: Steven G
authors.initials: SG
authors.lastname: Dubois
authors.forename: Holcombe E
authors.initials: HE
authors.lastname: Grier
authors.forename: Sung-Yun
authors.initials: SY
authors.lastname: Pai
authors.forename: Robert C
authors.initials: RC
authors.lastname: Shamberger
authors.forename: Harry P W
authors.initials: HP
authors.lastname: Kozakewich
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005192:Family Health; D017809:Fatal Outcome; D005260:Female; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation; D006801:Humans; D016864:Li-Fraumeni Syndrome / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008067:Lipoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008080:Liposarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D010375:Pedigree; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2