p53+/mdm2- atypical lipomatous tumor/well-differentiated liposarcoma in young children: an early expression of Li-Fraumeni syndrome

Pediatr Dev Pathol. May-Jun 2010;13(3):218-24. doi: 10.2350/09-08-0694-OA.1.


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.

Publication types

  • Case Reports

MeSH terms

  • Biomarkers, Tumor / metabolism
  • Child
  • Child, Preschool
  • Family Health
  • Fatal Outcome
  • Female
  • Genetic Predisposition to Disease
  • Germ-Line Mutation
  • Humans
  • Li-Fraumeni Syndrome / genetics
  • Li-Fraumeni Syndrome / metabolism
  • Li-Fraumeni Syndrome / pathology*
  • Lipoma / genetics
  • Lipoma / metabolism
  • Lipoma / pathology*
  • Liposarcoma / genetics
  • Liposarcoma / metabolism
  • Liposarcoma / pathology*
  • Male
  • Pedigree
  • Proto-Oncogene Proteins c-mdm2 / metabolism*
  • Tumor Suppressor Protein p53 / metabolism*


  • Biomarkers, Tumor
  • Tumor Suppressor Protein p53
  • MDM2 protein, human
  • Proto-Oncogene Proteins c-mdm2